diff --git a/solr/CHANGES.txt b/solr/CHANGES.txt
index 6a99ddc..556ac61 100644
--- a/solr/CHANGES.txt
+++ b/solr/CHANGES.txt
@@ -333,6 +333,8 @@
 
 * SOLR-13843: The MOVEREPLICA API ignores replica type and always adds 'nrt' replicas (Amrit Sarkar via shalin)
 
+* SOLR-13677: All Metrics Gauges should be unregistered by components that registered them. (noble, ab)
+
 Other Changes
 ----------------------
 
diff --git a/solr/contrib/dataimporthandler/src/java/org/apache/solr/handler/dataimport/DataImportHandler.java b/solr/contrib/dataimporthandler/src/java/org/apache/solr/handler/dataimport/DataImportHandler.java
index 50938e4..8b64b6f 100644
--- a/solr/contrib/dataimporthandler/src/java/org/apache/solr/handler/dataimport/DataImportHandler.java
+++ b/solr/contrib/dataimporthandler/src/java/org/apache/solr/handler/dataimport/DataImportHandler.java
@@ -36,7 +36,7 @@
 import org.apache.solr.core.SolrResourceLoader;
 import org.apache.solr.handler.RequestHandlerBase;
 import org.apache.solr.metrics.MetricsMap;
-import org.apache.solr.metrics.SolrMetricManager;
+import org.apache.solr.metrics.SolrMetricsContext;
 import org.apache.solr.request.SolrQueryRequest;
 import org.apache.solr.response.RawResponseWriter;
 import org.apache.solr.response.SolrQueryResponse;
@@ -275,8 +275,8 @@
   }
 
   @Override
-  public void initializeMetrics(SolrMetricManager manager, String registryName, String tag, String scope) {
-    super.initializeMetrics(manager, registryName, tag, scope);
+  public void initializeMetrics(SolrMetricsContext parentContext, String scope) {
+    super.initializeMetrics(parentContext, scope);
     metrics = new MetricsMap((detailed, map) -> {
       if (importer != null) {
         DocBuilder.Statistics cumulative = importer.cumulativeStatistics;
@@ -299,7 +299,7 @@
         map.put(DataImporter.MSG.TOTAL_DOCS_SKIPPED, cumulative.skipDocCount);
       }
     });
-    manager.registerGauge(this, registryName, metrics, tag, true, "importer", getCategory().toString(), scope);
+    solrMetricsContext.gauge(this, metrics, true, "importer", getCategory().toString(), scope);
   }
 
   // //////////////////////SolrInfoMBeans methods //////////////////////
diff --git a/solr/core/src/java/org/apache/solr/cloud/ReplicateFromLeader.java b/solr/core/src/java/org/apache/solr/cloud/ReplicateFromLeader.java
index 957b321..17a6ec3 100644
--- a/solr/core/src/java/org/apache/solr/cloud/ReplicateFromLeader.java
+++ b/solr/core/src/java/org/apache/solr/cloud/ReplicateFromLeader.java
@@ -133,7 +133,7 @@
 
   public void stopReplication() {
     if (replicationProcess != null) {
-      replicationProcess.close();
+      replicationProcess.shutdown();
     }
   }
 }
diff --git a/solr/core/src/java/org/apache/solr/core/CoreContainer.java b/solr/core/src/java/org/apache/solr/core/CoreContainer.java
index 054bd67..e9c6273 100644
--- a/solr/core/src/java/org/apache/solr/core/CoreContainer.java
+++ b/solr/core/src/java/org/apache/solr/core/CoreContainer.java
@@ -100,6 +100,7 @@
 import org.apache.solr.metrics.SolrCoreMetricManager;
 import org.apache.solr.metrics.SolrMetricManager;
 import org.apache.solr.metrics.SolrMetricProducer;
+import org.apache.solr.metrics.SolrMetricsContext;
 import org.apache.solr.request.SolrRequestHandler;
 import org.apache.solr.request.SolrRequestInfo;
 import org.apache.solr.search.SolrFieldCacheBean;
@@ -210,7 +211,9 @@
 
   protected volatile SolrMetricManager metricManager;
 
-  protected volatile String metricTag = Integer.toHexString(hashCode());
+  protected volatile String metricTag = SolrMetricProducer.getUniqueMetricTag(this, null);
+
+  protected volatile SolrMetricsContext solrMetricsContext;
 
   protected MetricsHandler metricsHandler;
 
@@ -612,6 +615,8 @@
     containerHandlers.getApiBag().register(new AnnotatedApi(packageStoreAPI.writeAPI), Collections.EMPTY_MAP);
 
     metricManager = new SolrMetricManager(loader, cfg.getMetricsConfig());
+    String registryName = SolrMetricManager.getRegistryName(SolrInfoBean.Group.node);
+    solrMetricsContext = new SolrMetricsContext(metricManager, registryName, metricTag);
 
     coreContainerWorkExecutor = MetricUtils.instrumentedExecutorService(
         coreContainerWorkExecutor, null,
@@ -625,7 +630,7 @@
     }
 
     updateShardHandler = new UpdateShardHandler(cfg.getUpdateShardHandlerConfig());
-    updateShardHandler.initializeMetrics(metricManager, SolrInfoBean.Group.node.toString(), metricTag, "updateShardHandler");
+    updateShardHandler.initializeMetrics(solrMetricsContext, "updateShardHandler");
 
     solrCores.load(loader);
 
@@ -638,7 +643,9 @@
     if (isZooKeeperAware()) {
       pkiAuthenticationPlugin = new PKIAuthenticationPlugin(this, zkSys.getZkController().getNodeName(),
           (PublicKeyHandler) containerHandlers.get(PublicKeyHandler.PATH));
-      pkiAuthenticationPlugin.initializeMetrics(metricManager, SolrInfoBean.Group.node.toString(), metricTag, "/authentication/pki");
+      // use deprecated API for back-compat, remove in 9.0
+      pkiAuthenticationPlugin.initializeMetrics(
+          solrMetricsContext.metricManager, solrMetricsContext.registry, solrMetricsContext.tag, "/authentication/pki");
       TracerConfigurator.loadTracer(loader, cfg.getTracerConfiguratorPluginInfo(), getZkController().getZkStateReader());
     }
 
@@ -668,7 +675,7 @@
     metricsCollectorHandler.init(null);
 
     containerHandlers.put(AUTHZ_PATH, securityConfHandler);
-    securityConfHandler.initializeMetrics(metricManager, SolrInfoBean.Group.node.toString(), metricTag, AUTHZ_PATH);
+    securityConfHandler.initializeMetrics(solrMetricsContext, AUTHZ_PATH);
     containerHandlers.put(AUTHC_PATH, securityConfHandler);
 
 
@@ -683,22 +690,20 @@
 
     // initialize gauges for reporting the number of cores and disk total/free
 
-    String registryName = SolrMetricManager.getRegistryName(SolrInfoBean.Group.node);
-    String metricTag = Integer.toHexString(hashCode());
-    metricManager.registerGauge(null, registryName, () -> solrCores.getCores().size(),
-        metricTag, true, "loaded", SolrInfoBean.Category.CONTAINER.toString(), "cores");
-    metricManager.registerGauge(null, registryName, () -> solrCores.getLoadedCoreNames().size() - solrCores.getCores().size(),
-        metricTag, true, "lazy", SolrInfoBean.Category.CONTAINER.toString(), "cores");
-    metricManager.registerGauge(null, registryName, () -> solrCores.getAllCoreNames().size() - solrCores.getLoadedCoreNames().size(),
-        metricTag, true, "unloaded", SolrInfoBean.Category.CONTAINER.toString(), "cores");
+    solrMetricsContext.gauge(null, () -> solrCores.getCores().size(),
+        true, "loaded", SolrInfoBean.Category.CONTAINER.toString(), "cores");
+    solrMetricsContext.gauge(null, () -> solrCores.getLoadedCoreNames().size() - solrCores.getCores().size(),
+        true, "lazy", SolrInfoBean.Category.CONTAINER.toString(), "cores");
+    solrMetricsContext.gauge(null, () -> solrCores.getAllCoreNames().size() - solrCores.getLoadedCoreNames().size(),
+        true, "unloaded", SolrInfoBean.Category.CONTAINER.toString(), "cores");
     Path dataHome = cfg.getSolrDataHome() != null ? cfg.getSolrDataHome() : cfg.getCoreRootDirectory();
-    metricManager.registerGauge(null, registryName, () -> dataHome.toFile().getTotalSpace(),
-        metricTag, true, "totalSpace", SolrInfoBean.Category.CONTAINER.toString(), "fs");
-    metricManager.registerGauge(null, registryName, () -> dataHome.toFile().getUsableSpace(),
-        metricTag, true, "usableSpace", SolrInfoBean.Category.CONTAINER.toString(), "fs");
-    metricManager.registerGauge(null, registryName, () -> dataHome.toAbsolutePath().toString(),
-        metricTag, true, "path", SolrInfoBean.Category.CONTAINER.toString(), "fs");
-    metricManager.registerGauge(null, registryName, () -> {
+    solrMetricsContext.gauge(null, () -> dataHome.toFile().getTotalSpace(),
+        true, "totalSpace", SolrInfoBean.Category.CONTAINER.toString(), "fs");
+    solrMetricsContext.gauge(null, () -> dataHome.toFile().getUsableSpace(),
+        true, "usableSpace", SolrInfoBean.Category.CONTAINER.toString(), "fs");
+    solrMetricsContext.gauge(null, () -> dataHome.toAbsolutePath().toString(),
+        true, "path", SolrInfoBean.Category.CONTAINER.toString(), "fs");
+    solrMetricsContext.gauge(null, () -> {
           try {
             return org.apache.lucene.util.IOUtils.spins(dataHome.toAbsolutePath());
           } catch (IOException e) {
@@ -706,14 +711,14 @@
             return true;
           }
         },
-        metricTag, true, "spins", SolrInfoBean.Category.CONTAINER.toString(), "fs");
-    metricManager.registerGauge(null, registryName, () -> cfg.getCoreRootDirectory().toFile().getTotalSpace(),
-        metricTag, true, "totalSpace", SolrInfoBean.Category.CONTAINER.toString(), "fs", "coreRoot");
-    metricManager.registerGauge(null, registryName, () -> cfg.getCoreRootDirectory().toFile().getUsableSpace(),
-        metricTag, true, "usableSpace", SolrInfoBean.Category.CONTAINER.toString(), "fs", "coreRoot");
-    metricManager.registerGauge(null, registryName, () -> cfg.getCoreRootDirectory().toAbsolutePath().toString(),
-        metricTag, true, "path", SolrInfoBean.Category.CONTAINER.toString(), "fs", "coreRoot");
-    metricManager.registerGauge(null, registryName, () -> {
+        true, "spins", SolrInfoBean.Category.CONTAINER.toString(), "fs");
+    solrMetricsContext.gauge(null, () -> cfg.getCoreRootDirectory().toFile().getTotalSpace(),
+        true, "totalSpace", SolrInfoBean.Category.CONTAINER.toString(), "fs", "coreRoot");
+    solrMetricsContext.gauge(null, () -> cfg.getCoreRootDirectory().toFile().getUsableSpace(),
+        true, "usableSpace", SolrInfoBean.Category.CONTAINER.toString(), "fs", "coreRoot");
+    solrMetricsContext.gauge(null, () -> cfg.getCoreRootDirectory().toAbsolutePath().toString(),
+        true, "path", SolrInfoBean.Category.CONTAINER.toString(), "fs", "coreRoot");
+    solrMetricsContext.gauge(null, () -> {
           try {
             return org.apache.lucene.util.IOUtils.spins(cfg.getCoreRootDirectory().toAbsolutePath());
           } catch (IOException e) {
@@ -721,15 +726,15 @@
             return true;
           }
         },
-        metricTag, true, "spins", SolrInfoBean.Category.CONTAINER.toString(), "fs", "coreRoot");
+        true, "spins", SolrInfoBean.Category.CONTAINER.toString(), "fs", "coreRoot");
     // add version information
-    metricManager.registerGauge(null, registryName, () -> this.getClass().getPackage().getSpecificationVersion(),
-        metricTag, true, "specification", SolrInfoBean.Category.CONTAINER.toString(), "version");
-    metricManager.registerGauge(null, registryName, () -> this.getClass().getPackage().getImplementationVersion(),
-        metricTag, true, "implementation", SolrInfoBean.Category.CONTAINER.toString(), "version");
+    solrMetricsContext.gauge(null, () -> this.getClass().getPackage().getSpecificationVersion(),
+        true, "specification", SolrInfoBean.Category.CONTAINER.toString(), "version");
+    solrMetricsContext.gauge(null, () -> this.getClass().getPackage().getImplementationVersion(),
+        true, "implementation", SolrInfoBean.Category.CONTAINER.toString(), "version");
 
     SolrFieldCacheBean fieldCacheBean = new SolrFieldCacheBean();
-    fieldCacheBean.initializeMetrics(metricManager, registryName, metricTag, null);
+    fieldCacheBean.initializeMetrics(solrMetricsContext, null);
 
     if (isZooKeeperAware()) {
       metricManager.loadClusterReporters(metricReporters, this);
@@ -818,7 +823,7 @@
       // initialize this handler here when SolrCloudManager is ready
       autoScalingHandler = new AutoScalingHandler(getZkController().getSolrCloudManager(), loader);
       containerHandlers.put(AutoScalingHandler.HANDLER_PATH, autoScalingHandler);
-      autoScalingHandler.initializeMetrics(metricManager, SolrInfoBean.Group.node.toString(), metricTag, AutoScalingHandler.HANDLER_PATH);
+      autoScalingHandler.initializeMetrics(solrMetricsContext, AutoScalingHandler.HANDLER_PATH);
     }
     // This is a bit redundant but these are two distinct concepts for all they're accomplished at the same time.
     status |= LOAD_COMPLETE | INITIAL_CORE_LOAD_COMPLETE;
@@ -866,7 +871,7 @@
     metricsHistoryHandler = new MetricsHistoryHandler(name, metricsHandler,
         client, cloudManager, initArgs);
     containerHandlers.put(METRICS_HISTORY_PATH, metricsHistoryHandler);
-    metricsHistoryHandler.initializeMetrics(metricManager, SolrInfoBean.Group.node.toString(), metricTag, METRICS_HISTORY_PATH);
+    metricsHistoryHandler.initializeMetrics(solrMetricsContext, METRICS_HISTORY_PATH);
   }
 
   public void securityNodeChanged() {
@@ -1788,7 +1793,9 @@
       containerHandlers.put(path, (SolrRequestHandler) handler);
     }
     if (handler instanceof SolrMetricProducer) {
-      ((SolrMetricProducer) handler).initializeMetrics(metricManager, SolrInfoBean.Group.node.toString(), metricTag, path);
+      // use deprecated method for back-compat, remove in 9.0
+      ((SolrMetricProducer) handler).initializeMetrics(solrMetricsContext.metricManager,
+          solrMetricsContext.registry, solrMetricsContext.tag, path);
     }
     return handler;
   }
diff --git a/solr/core/src/java/org/apache/solr/core/HdfsDirectoryFactory.java b/solr/core/src/java/org/apache/solr/core/HdfsDirectoryFactory.java
index 464b030..942f429 100644
--- a/solr/core/src/java/org/apache/solr/core/HdfsDirectoryFactory.java
+++ b/solr/core/src/java/org/apache/solr/core/HdfsDirectoryFactory.java
@@ -53,8 +53,8 @@
 import org.apache.solr.common.params.SolrParams;
 import org.apache.solr.common.util.IOUtils;
 import org.apache.solr.common.util.NamedList;
-import org.apache.solr.metrics.SolrMetricManager;
 import org.apache.solr.metrics.SolrMetricProducer;
+import org.apache.solr.metrics.SolrMetricsContext;
 import org.apache.solr.store.blockcache.BlockCache;
 import org.apache.solr.store.blockcache.BlockDirectory;
 import org.apache.solr.store.blockcache.BlockDirectoryCache;
@@ -141,6 +141,13 @@
     }
     tmpFsCache.invalidateAll();
     tmpFsCache.cleanUp();
+    try {
+      SolrMetricProducer.super.close();
+      MetricsHolder.metrics.close();
+      LocalityHolder.reporter.close();
+    } catch (Exception e) {
+      throw new IOException(e);
+    }
   }
 
   private final static class LocalityHolder {
@@ -497,9 +504,9 @@
   }
 
   @Override
-  public void initializeMetrics(SolrMetricManager manager, String registry, String tag, String scope) {
-    MetricsHolder.metrics.initializeMetrics(manager, registry, tag, scope);
-    LocalityHolder.reporter.initializeMetrics(manager, registry, tag, scope);
+  public void initializeMetrics(SolrMetricsContext parentContext, String scope) {
+    MetricsHolder.metrics.initializeMetrics(parentContext, scope);
+    LocalityHolder.reporter.initializeMetrics(parentContext, scope);
   }
 
   @Override
diff --git a/solr/core/src/java/org/apache/solr/core/PluginBag.java b/solr/core/src/java/org/apache/solr/core/PluginBag.java
index 6088f52..fa2c3e3 100644
--- a/solr/core/src/java/org/apache/solr/core/PluginBag.java
+++ b/solr/core/src/java/org/apache/solr/core/PluginBag.java
@@ -195,7 +195,7 @@
     return old == null ? null : old.get();
   }
 
-  PluginHolder<T> put(String name, PluginHolder<T> plugin) {
+  public PluginHolder<T> put(String name, PluginHolder<T> plugin) {
     Boolean registerApi = null;
     Boolean disableHandler = null;
     if (plugin.pluginInfo != null) {
@@ -231,11 +231,15 @@
           apiBag.registerLazy((PluginHolder<SolrRequestHandler>) plugin, plugin.pluginInfo);
       }
     }
-    if(disableHandler == null) disableHandler = Boolean.FALSE;
+    if (disableHandler == null) disableHandler = Boolean.FALSE;
     PluginHolder<T> old = null;
-    if(!disableHandler) old = registry.put(name, plugin);
+    if (!disableHandler) old = registry.put(name, plugin);
     if (plugin.pluginInfo != null && plugin.pluginInfo.isDefault()) setDefault(name);
     if (plugin.isLoaded()) registerMBean(plugin.get(), core, name);
+    // old instance has been replaced - close it to prevent mem leaks
+    if (old != null && old != plugin) {
+      closeQuietly(old);
+    }
     return old;
   }
 
@@ -324,6 +328,14 @@
     }
   }
 
+  public static void closeQuietly(Object inst)  {
+    try {
+      if (inst != null && inst instanceof AutoCloseable) ((AutoCloseable) inst).close();
+    } catch (Exception e) {
+      log.error("Error closing "+ inst , e);
+    }
+  }
+
   /**
    * An indirect reference to a plugin. It just wraps a plugin instance.
    * subclasses may choose to lazily load the plugin
diff --git a/solr/core/src/java/org/apache/solr/core/SolrCore.java b/solr/core/src/java/org/apache/solr/core/SolrCore.java
index 3e2fb1e..ce018a5 100644
--- a/solr/core/src/java/org/apache/solr/core/SolrCore.java
+++ b/solr/core/src/java/org/apache/solr/core/SolrCore.java
@@ -108,8 +108,8 @@
 import org.apache.solr.handler.component.SearchComponent;
 import org.apache.solr.logging.MDCLoggingContext;
 import org.apache.solr.metrics.SolrCoreMetricManager;
-import org.apache.solr.metrics.SolrMetricManager;
 import org.apache.solr.metrics.SolrMetricProducer;
+import org.apache.solr.metrics.SolrMetricsContext;
 import org.apache.solr.request.SolrQueryRequest;
 import org.apache.solr.request.SolrRequestHandler;
 import org.apache.solr.response.BinaryResponseWriter;
@@ -231,7 +231,8 @@
   private final CoreContainer coreContainer;
 
   private Set<String> metricNames = ConcurrentHashMap.newKeySet();
-  private String metricTag = Integer.toHexString(hashCode());
+  private final String metricTag = SolrMetricProducer.getUniqueMetricTag(this, null);
+  private final SolrMetricsContext solrMetricsContext;
 
   public volatile boolean searchEnabled = true;
   public volatile boolean indexEnabled = true;
@@ -919,6 +920,7 @@
       this.configSetProperties = configSetProperties;
       // Initialize the metrics manager
       this.coreMetricManager = initCoreMetricManager(config);
+      solrMetricsContext = coreMetricManager.getSolrMetricsContext();
       this.coreMetricManager.loadReporters();
 
       if (updateHandler == null) {
@@ -940,15 +942,13 @@
 
       checkVersionFieldExistsInSchema(schema, coreDescriptor);
 
-      SolrMetricManager metricManager = coreContainer.getMetricManager();
-
       // initialize searcher-related metrics
-      initializeMetrics(metricManager, coreMetricManager.getRegistryName(), metricTag, null);
+      initializeMetrics(solrMetricsContext, null);
 
       SolrFieldCacheBean solrFieldCacheBean = new SolrFieldCacheBean();
       // this is registered at the CONTAINER level because it's not core-specific - for now we
       // also register it here for back-compat
-      solrFieldCacheBean.initializeMetrics(metricManager, coreMetricManager.getRegistryName(), metricTag, "core");
+      solrFieldCacheBean.initializeMetrics(solrMetricsContext, "core");
       infoRegistry.put("fieldCache", solrFieldCacheBean);
 
       initSchema(config, schema);
@@ -1015,8 +1015,9 @@
 
       // Allow the directory factory to report metrics
       if (directoryFactory instanceof SolrMetricProducer) {
-        ((SolrMetricProducer) directoryFactory).initializeMetrics(metricManager, coreMetricManager.getRegistryName(),
-            metricTag, "directoryFactory");
+        // XXX use deprecated method for back-compat, remove in 9.0
+        ((SolrMetricProducer) directoryFactory).initializeMetrics(
+            solrMetricsContext.metricManager, solrMetricsContext.registry, solrMetricsContext.tag, "directoryFactory");
       }
 
       // seed version buckets with max from index during core initialization ... requires a searcher!
@@ -1163,61 +1164,66 @@
   }
 
   @Override
-  public void initializeMetrics(SolrMetricManager manager, String registry, String tag, String scope) {
-    newSearcherCounter = manager.counter(this, registry, "new", Category.SEARCHER.toString());
-    newSearcherTimer = manager.timer(this, registry, "time", Category.SEARCHER.toString(), "new");
-    newSearcherWarmupTimer = manager.timer(this, registry, "warmup", Category.SEARCHER.toString(), "new");
-    newSearcherMaxReachedCounter = manager.counter(this, registry, "maxReached", Category.SEARCHER.toString(), "new");
-    newSearcherOtherErrorsCounter = manager.counter(this, registry, "errors", Category.SEARCHER.toString(), "new");
+  public void initializeMetrics(SolrMetricsContext parentContext, String scope) {
+    newSearcherCounter = parentContext.counter(this, "new", Category.SEARCHER.toString());
+    newSearcherTimer = parentContext.timer(this, "time", Category.SEARCHER.toString(), "new");
+    newSearcherWarmupTimer = parentContext.timer(this, "warmup", Category.SEARCHER.toString(), "new");
+    newSearcherMaxReachedCounter = parentContext.counter(this, "maxReached", Category.SEARCHER.toString(), "new");
+    newSearcherOtherErrorsCounter = parentContext.counter(this, "errors", Category.SEARCHER.toString(), "new");
 
-    manager.registerGauge(this, registry, () -> name == null ? "(null)" : name, getMetricTag(), true, "coreName", Category.CORE.toString());
-    manager.registerGauge(this, registry, () -> startTime, getMetricTag(), true, "startTime", Category.CORE.toString());
-    manager.registerGauge(this, registry, () -> getOpenCount(), getMetricTag(), true, "refCount", Category.CORE.toString());
-    manager.registerGauge(this, registry, () -> resourceLoader.getInstancePath().toString(), getMetricTag(), true, "instanceDir", Category.CORE.toString());
-    manager.registerGauge(this, registry, () -> isClosed() ? "(closed)" : getIndexDir(), getMetricTag(), true, "indexDir", Category.CORE.toString());
-    manager.registerGauge(this, registry, () -> isClosed() ? 0 : getIndexSize(), getMetricTag(), true, "sizeInBytes", Category.INDEX.toString());
-    manager.registerGauge(this, registry, () -> isClosed() ? "(closed)" : NumberUtils.readableSize(getIndexSize()), getMetricTag(), true, "size", Category.INDEX.toString());
+    parentContext.gauge(this, () -> name == null ? "(null)" : name, true, "coreName", Category.CORE.toString());
+    parentContext.gauge(this, () -> startTime, true, "startTime", Category.CORE.toString());
+    parentContext.gauge(this, () -> getOpenCount(), true, "refCount", Category.CORE.toString());
+    parentContext.gauge(this, () -> resourceLoader.getInstancePath().toString(), true, "instanceDir", Category.CORE.toString());
+    parentContext.gauge(this, () -> isClosed() ? "(closed)" : getIndexDir(), true, "indexDir", Category.CORE.toString());
+    parentContext.gauge(this, () -> isClosed() ? 0 : getIndexSize(), true, "sizeInBytes", Category.INDEX.toString());
+    parentContext.gauge(this, () -> isClosed() ? "(closed)" : NumberUtils.readableSize(getIndexSize()), true, "size", Category.INDEX.toString());
     if (coreContainer != null) {
-      manager.registerGauge(this, registry, () -> coreContainer.getNamesForCore(this), getMetricTag(), true, "aliases", Category.CORE.toString());
+      parentContext.gauge(this, () -> coreContainer.getNamesForCore(this), true, "aliases", Category.CORE.toString());
       final CloudDescriptor cd = getCoreDescriptor().getCloudDescriptor();
       if (cd != null) {
-        manager.registerGauge(this, registry, () -> {
+        parentContext.gauge(this, () -> {
           if (cd.getCollectionName() != null) {
             return cd.getCollectionName();
           } else {
             return "_notset_";
           }
-        }, getMetricTag(), true, "collection", Category.CORE.toString());
+        }, true, "collection", Category.CORE.toString());
 
-        manager.registerGauge(this, registry, () -> {
+        parentContext.gauge(this, () -> {
           if (cd.getShardId() != null) {
             return cd.getShardId();
           } else {
             return "_auto_";
           }
-        }, getMetricTag(), true, "shard", Category.CORE.toString());
+        }, true, "shard", Category.CORE.toString());
       }
     }
     // initialize disk total / free metrics
     Path dataDirPath = Paths.get(dataDir);
     File dataDirFile = dataDirPath.toFile();
-    manager.registerGauge(this, registry, () -> dataDirFile.getTotalSpace(), getMetricTag(), true, "totalSpace", Category.CORE.toString(), "fs");
-    manager.registerGauge(this, registry, () -> dataDirFile.getUsableSpace(), getMetricTag(), true, "usableSpace", Category.CORE.toString(), "fs");
-    manager.registerGauge(this, registry, () -> dataDirPath.toAbsolutePath().toString(), getMetricTag(), true, "path", Category.CORE.toString(), "fs");
-    manager.registerGauge(this, registry, () -> {
+    parentContext.gauge(this, () -> dataDirFile.getTotalSpace(), true, "totalSpace", Category.CORE.toString(), "fs");
+    parentContext.gauge(this, () -> dataDirFile.getUsableSpace(), true, "usableSpace", Category.CORE.toString(), "fs");
+    parentContext.gauge(this, () -> dataDirPath.toAbsolutePath().toString(), true, "path", Category.CORE.toString(), "fs");
+    parentContext.gauge(this, () -> {
       try {
         return org.apache.lucene.util.IOUtils.spins(dataDirPath.toAbsolutePath());
       } catch (IOException e) {
         // default to spinning
         return true;
       }
-    }, getMetricTag(), true, "spins", Category.CORE.toString(), "fs");
+    }, true, "spins", Category.CORE.toString(), "fs");
   }
 
   public String getMetricTag() {
     return metricTag;
   }
 
+  @Override
+  public SolrMetricsContext getSolrMetricsContext() {
+    return solrMetricsContext;
+  }
+
   private void checkVersionFieldExistsInSchema(IndexSchema schema, CoreDescriptor coreDescriptor) {
     if (null != coreDescriptor.getCloudDescriptor()) {
       // we are evidently running in cloud mode.  
diff --git a/solr/core/src/java/org/apache/solr/core/SolrInfoBean.java b/solr/core/src/java/org/apache/solr/core/SolrInfoBean.java
index bfb3428..dc0f599 100644
--- a/solr/core/src/java/org/apache/solr/core/SolrInfoBean.java
+++ b/solr/core/src/java/org/apache/solr/core/SolrInfoBean.java
@@ -21,6 +21,8 @@
 
 import com.codahale.metrics.MetricRegistry;
 import org.apache.solr.metrics.SolrMetricManager;
+import org.apache.solr.metrics.SolrMetricProducer;
+import org.apache.solr.metrics.SolrMetricsContext;
 import org.apache.solr.util.stats.MetricUtils;
 
 /**
@@ -77,6 +79,10 @@
    * (default is null, which means no registry).
    */
   default MetricRegistry getMetricRegistry() {
+    if (this instanceof SolrMetricProducer) {
+      SolrMetricsContext context = ((SolrMetricProducer)this).getSolrMetricsContext();
+      return context != null ? context.getMetricRegistry() : null;
+    }
     return null;
   }
 
diff --git a/solr/core/src/java/org/apache/solr/handler/ReplicationHandler.java b/solr/core/src/java/org/apache/solr/handler/ReplicationHandler.java
index dc1d1b1..6f905c7 100644
--- a/solr/core/src/java/org/apache/solr/handler/ReplicationHandler.java
+++ b/solr/core/src/java/org/apache/solr/handler/ReplicationHandler.java
@@ -92,7 +92,7 @@
 import org.apache.solr.core.backup.repository.LocalFileSystemRepository;
 import org.apache.solr.handler.IndexFetcher.IndexFetchResult;
 import org.apache.solr.metrics.MetricsMap;
-import org.apache.solr.metrics.SolrMetricManager;
+import org.apache.solr.metrics.SolrMetricsContext;
 import org.apache.solr.request.SolrQueryRequest;
 import org.apache.solr.response.SolrQueryResponse;
 import org.apache.solr.search.SolrIndexSearcher;
@@ -863,21 +863,20 @@
   }
 
   @Override
-  public void initializeMetrics(SolrMetricManager manager, String registry, String tag, String scope) {
-    super.initializeMetrics(manager, registry, tag, scope);
-
-    manager.registerGauge(this, registry, () -> (core != null && !core.isClosed() ? NumberUtils.readableSize(core.getIndexSize()) : ""),
-        tag, true, "indexSize", getCategory().toString(), scope);
-    manager.registerGauge(this, registry, () -> (core != null && !core.isClosed() ? getIndexVersion().toString() : ""),
-        tag, true, "indexVersion", getCategory().toString(), scope);
-    manager.registerGauge(this, registry, () -> (core != null && !core.isClosed() ? getIndexVersion().generation : 0),
-        tag, true, GENERATION, getCategory().toString(), scope);
-    manager.registerGauge(this, registry, () -> (core != null && !core.isClosed() ? core.getIndexDir() : ""),
-        tag, true, "indexPath", getCategory().toString(), scope);
-    manager.registerGauge(this, registry, () -> isMaster,
-        tag, true, "isMaster", getCategory().toString(), scope);
-    manager.registerGauge(this, registry, () -> isSlave,
-        tag, true, "isSlave", getCategory().toString(), scope);
+  public void initializeMetrics(SolrMetricsContext parentContext, String scope) {
+    super.initializeMetrics(parentContext, scope);
+    solrMetricsContext.gauge(this,  () -> (core != null && !core.isClosed() ? NumberUtils.readableSize(core.getIndexSize()) : ""),
+        true, "indexSize", getCategory().toString(), scope);
+    solrMetricsContext.gauge(this, () -> (core != null && !core.isClosed() ? getIndexVersion().toString() : ""),
+         true, "indexVersion", getCategory().toString(), scope);
+    solrMetricsContext.gauge(this, () -> (core != null && !core.isClosed() ? getIndexVersion().generation : 0),
+        true, GENERATION, getCategory().toString(), scope);
+    solrMetricsContext.gauge(this, () -> (core != null && !core.isClosed() ? core.getIndexDir() : ""),
+        true, "indexPath", getCategory().toString(), scope);
+    solrMetricsContext.gauge(this, () -> isMaster,
+         true, "isMaster", getCategory().toString(), scope);
+    solrMetricsContext.gauge(this, () -> isSlave,
+         true, "isSlave", getCategory().toString(), scope);
     final MetricsMap fetcherMap = new MetricsMap((detailed, map) -> {
       IndexFetcher fetcher = currentIndexFetcher;
       if (fetcher != null) {
@@ -906,13 +905,13 @@
         addVal(map, IndexFetcher.CONF_FILES_REPLICATED, props, String.class);
       }
     });
-    manager.registerGauge(this, registry, fetcherMap, tag, true, "fetcher", getCategory().toString(), scope);
-    manager.registerGauge(this, registry, () -> isMaster && includeConfFiles != null ? includeConfFiles : "",
-        tag, true, "confFilesToReplicate", getCategory().toString(), scope);
-    manager.registerGauge(this, registry, () -> isMaster ? getReplicateAfterStrings() : Collections.<String>emptyList(),
-        tag, true, REPLICATE_AFTER, getCategory().toString(), scope);
-    manager.registerGauge(this, registry, () -> isMaster && replicationEnabled.get(),
-        tag, true, "replicationEnabled", getCategory().toString(), scope);
+    solrMetricsContext.gauge(this , fetcherMap, true, "fetcher", getCategory().toString(), scope);
+    solrMetricsContext.gauge(this, () -> isMaster && includeConfFiles != null ? includeConfFiles : "",
+         true, "confFilesToReplicate", getCategory().toString(), scope);
+    solrMetricsContext.gauge(this, () -> isMaster ? getReplicateAfterStrings() : Collections.<String>emptyList(),
+        true, REPLICATE_AFTER, getCategory().toString(), scope);
+    solrMetricsContext.gauge(this,  () -> isMaster && replicationEnabled.get(),
+        true, "replicationEnabled", getCategory().toString(), scope);
   }
 
   //TODO Should a failure retrieving any piece of info mark the overall request as a failure?  Is there a core set of values that are required to make a response here useful?
@@ -1387,7 +1386,7 @@
     });
   }
 
-  public void close() {
+  public void shutdown() {
     if (executorService != null) executorService.shutdown();
     if (pollingIndexFetcher != null) {
       pollingIndexFetcher.destroy();
diff --git a/solr/core/src/java/org/apache/solr/handler/RequestHandlerBase.java b/solr/core/src/java/org/apache/solr/handler/RequestHandlerBase.java
index eca391b..4d9e96b 100644
--- a/solr/core/src/java/org/apache/solr/handler/RequestHandlerBase.java
+++ b/solr/core/src/java/org/apache/solr/handler/RequestHandlerBase.java
@@ -22,11 +22,13 @@
 import java.util.Set;
 import java.util.concurrent.ConcurrentHashMap;
 
-import com.codahale.metrics.MetricRegistry;
-import com.google.common.collect.ImmutableList;
 import com.codahale.metrics.Counter;
 import com.codahale.metrics.Meter;
 import com.codahale.metrics.Timer;
+import com.google.common.collect.ImmutableList;
+import org.apache.solr.api.Api;
+import org.apache.solr.api.ApiBag;
+import org.apache.solr.api.ApiSupport;
 import org.apache.solr.common.SolrException;
 import org.apache.solr.common.params.ShardParams;
 import org.apache.solr.common.params.SolrParams;
@@ -36,16 +38,13 @@
 import org.apache.solr.core.PluginInfo;
 import org.apache.solr.core.SolrInfoBean;
 import org.apache.solr.metrics.MetricsMap;
-import org.apache.solr.metrics.SolrMetricManager;
 import org.apache.solr.metrics.SolrMetricProducer;
+import org.apache.solr.metrics.SolrMetricsContext;
 import org.apache.solr.request.SolrQueryRequest;
 import org.apache.solr.request.SolrRequestHandler;
 import org.apache.solr.response.SolrQueryResponse;
 import org.apache.solr.search.SyntaxError;
 import org.apache.solr.util.SolrPluginUtils;
-import org.apache.solr.api.Api;
-import org.apache.solr.api.ApiBag;
-import org.apache.solr.api.ApiSupport;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
@@ -79,9 +78,7 @@
   private PluginInfo pluginInfo;
 
   private Set<String> metricNames = ConcurrentHashMap.newKeySet();
-  private MetricRegistry registry;
-  protected String registryName;
-  protected SolrMetricManager metricManager;
+  protected SolrMetricsContext solrMetricsContext;
 
 
   @SuppressForbidden(reason = "Need currentTimeMillis, used only for stats output")
@@ -144,21 +141,24 @@
   }
 
   @Override
-  public void initializeMetrics(SolrMetricManager manager, String registryName, String tag, final String scope) {
-    this.metricManager = manager;
-    this.registryName = registryName;
-    this.registry = manager.registry(registryName);
-    numErrors = manager.meter(this, registryName, "errors", getCategory().toString(), scope);
-    numServerErrors = manager.meter(this, registryName, "serverErrors", getCategory().toString(), scope);
-    numClientErrors = manager.meter(this, registryName, "clientErrors", getCategory().toString(), scope);
-    numTimeouts = manager.meter(this, registryName, "timeouts", getCategory().toString(), scope);
-    requests = manager.counter(this, registryName, "requests", getCategory().toString(), scope);
+  public SolrMetricsContext getSolrMetricsContext() {
+    return solrMetricsContext;
+  }
+
+  @Override
+  public void initializeMetrics(SolrMetricsContext parentContext, String scope) {
+    this.solrMetricsContext = parentContext.getChildContext(this);
+    numErrors = solrMetricsContext.meter(this, "errors", getCategory().toString(), scope);
+    numServerErrors = solrMetricsContext.meter(this, "serverErrors", getCategory().toString(), scope);
+    numClientErrors = solrMetricsContext.meter(this, "clientErrors", getCategory().toString(), scope);
+    numTimeouts = solrMetricsContext.meter(this, "timeouts", getCategory().toString(), scope);
+    requests = solrMetricsContext.counter(this, "requests", getCategory().toString(), scope);
     MetricsMap metricsMap = new MetricsMap((detail, map) ->
         shardPurposes.forEach((k, v) -> map.put(k, v.getCount())));
-    manager.registerGauge(this, registryName, metricsMap, tag, true, "shardRequests", getCategory().toString(), scope);
-    requestTimes = manager.timer(this, registryName, "requestTimes", getCategory().toString(), scope);
-    totalTime = manager.counter(this, registryName, "totalTime", getCategory().toString(), scope);
-    manager.registerGauge(this, registryName, () -> handlerStart, tag, true, "handlerStart", getCategory().toString(), scope);
+    solrMetricsContext.gauge(this, metricsMap, true, "shardRequests", getCategory().toString(), scope);
+    requestTimes = solrMetricsContext.timer(this,"requestTimes", getCategory().toString(), scope);
+    totalTime = solrMetricsContext.counter(this, "totalTime", getCategory().toString(), scope);
+    solrMetricsContext.gauge(this, () -> handlerStart, true, "handlerStart", getCategory().toString(), scope);
   }
 
   public static SolrParams getSolrParamsFromNamedList(NamedList args, String key) {
@@ -273,11 +273,6 @@
   }
 
   @Override
-  public MetricRegistry getMetricRegistry() {
-    return registry;
-  }
-
-  @Override
   public SolrRequestHandler getSubHandler(String subPath) {
     return null;
   }
diff --git a/solr/core/src/java/org/apache/solr/handler/admin/CoreAdminHandler.java b/solr/core/src/java/org/apache/solr/handler/admin/CoreAdminHandler.java
index cd6cd38..589a1ca 100644
--- a/solr/core/src/java/org/apache/solr/handler/admin/CoreAdminHandler.java
+++ b/solr/core/src/java/org/apache/solr/handler/admin/CoreAdminHandler.java
@@ -46,6 +46,7 @@
 import org.apache.solr.handler.RequestHandlerBase;
 import org.apache.solr.logging.MDCLoggingContext;
 import org.apache.solr.metrics.SolrMetricManager;
+import org.apache.solr.metrics.SolrMetricsContext;
 import org.apache.solr.request.SolrQueryRequest;
 import org.apache.solr.response.SolrQueryResponse;
 import org.apache.solr.security.AuthorizationContext;
@@ -120,10 +121,10 @@
   }
 
   @Override
-  public void initializeMetrics(SolrMetricManager manager, String registryName, String tag, String scope) {
-    super.initializeMetrics(manager, registryName, tag, scope);
-    parallelExecutor = MetricUtils.instrumentedExecutorService(parallelExecutor, this, manager.registry(registryName),
-        SolrMetricManager.mkName("parallelCoreAdminExecutor", getCategory().name(),scope, "threadPool"));
+  public void initializeMetrics(SolrMetricsContext parentContext, String scope) {
+    super.initializeMetrics(parentContext, scope);
+    parallelExecutor = MetricUtils.instrumentedExecutorService(parallelExecutor, this, solrMetricsContext.getMetricRegistry(),
+        SolrMetricManager.mkName("parallelCoreAdminExecutor", getCategory().name(), scope, "threadPool"));
   }
   @Override
   public Boolean registerV2() {
diff --git a/solr/core/src/java/org/apache/solr/handler/component/SuggestComponent.java b/solr/core/src/java/org/apache/solr/handler/component/SuggestComponent.java
index 2d6fdb1..d70cf99 100644
--- a/solr/core/src/java/org/apache/solr/handler/component/SuggestComponent.java
+++ b/solr/core/src/java/org/apache/solr/handler/component/SuggestComponent.java
@@ -48,8 +48,8 @@
 import org.apache.solr.core.SolrCore;
 import org.apache.solr.core.SolrEventListener;
 import org.apache.solr.metrics.MetricsMap;
-import org.apache.solr.metrics.SolrMetricManager;
 import org.apache.solr.metrics.SolrMetricProducer;
+import org.apache.solr.metrics.SolrMetricsContext;
 import org.apache.solr.search.SolrIndexSearcher;
 import org.apache.solr.spelling.suggest.SolrSuggester;
 import org.apache.solr.spelling.suggest.SuggesterOptions;
@@ -88,9 +88,8 @@
   @SuppressWarnings("unchecked")
   protected NamedList initParams;
 
-  protected SolrMetricManager metricManager;
-  protected String registryName;
-  
+  protected SolrMetricsContext metricsContext;
+
   /**
    * Key is the dictionary name used in SolrConfig, value is the corresponding {@link SolrSuggester}
    */
@@ -351,18 +350,22 @@
   }
 
   @Override
-  public void initializeMetrics(SolrMetricManager manager, String registryName, String tag, String scope) {
-    this.registryName = registryName;
-    this.metricManager = manager;
-    registry = manager.registry(registryName);
-    manager.registerGauge(this, registryName, () -> ramBytesUsed(), tag, true, "totalSizeInBytes", getCategory().toString(), scope);
+  public SolrMetricsContext getSolrMetricsContext() {
+    return metricsContext;
+  }
+
+  @Override
+  public void initializeMetrics(SolrMetricsContext parentContext, String scope) {
+    this.metricsContext = parentContext.getChildContext(this);
+
+    this.metricsContext.gauge(this, () -> ramBytesUsed(), true, "totalSizeInBytes", getCategory().toString());
     MetricsMap suggestersMap = new MetricsMap((detailed, map) -> {
       for (Map.Entry<String, SolrSuggester> entry : suggesters.entrySet()) {
         SolrSuggester suggester = entry.getValue();
         map.put(entry.getKey(), suggester.toString());
       }
     });
-    manager.registerGauge(this, registryName, suggestersMap, tag, true, "suggesters", getCategory().toString(), scope);
+    this.metricsContext.gauge(this, suggestersMap, true, "suggesters", getCategory().toString(), scope);
   }
 
   @Override
diff --git a/solr/core/src/java/org/apache/solr/metrics/SolrCoreMetricManager.java b/solr/core/src/java/org/apache/solr/metrics/SolrCoreMetricManager.java
index c57a704..c318b8c 100644
--- a/solr/core/src/java/org/apache/solr/metrics/SolrCoreMetricManager.java
+++ b/solr/core/src/java/org/apache/solr/metrics/SolrCoreMetricManager.java
@@ -40,9 +40,8 @@
   private static final Logger log = LoggerFactory.getLogger(MethodHandles.lookup().lookupClass());
 
   private final SolrCore core;
-  private final String tag;
-  private final SolrMetricManager metricManager;
-  private String registryName;
+  private SolrMetricsContext solrMetricsContext;
+  private SolrMetricManager metricManager;
   private String collectionName;
   private String shardName;
   private String replicaName;
@@ -56,10 +55,10 @@
    */
   public SolrCoreMetricManager(SolrCore core) {
     this.core = core;
-    this.tag = core.getMetricTag();
-    this.metricManager = core.getCoreContainer().getMetricManager();
     initCloudMode();
-    registryName = createRegistryName(cloudMode, collectionName, shardName, replicaName, core.getName());
+    metricManager = core.getCoreContainer().getMetricManager();
+    String registryName = createRegistryName(cloudMode, collectionName, shardName, replicaName, core.getName());
+    solrMetricsContext = new SolrMetricsContext(metricManager, registryName, core.getMetricTag());
     leaderRegistryName = createLeaderRegistryName(cloudMode, collectionName, shardName);
   }
 
@@ -86,8 +85,8 @@
     CoreContainer coreContainer = core.getCoreContainer();
     NodeConfig nodeConfig = coreContainer.getConfig();
     PluginInfo[] pluginInfos = nodeConfig.getMetricsConfig().getMetricReporters();
-    metricManager.loadReporters(pluginInfos, core.getResourceLoader(), coreContainer, core, tag,
-        SolrInfoBean.Group.core, registryName);
+    metricManager.loadReporters(pluginInfos, core.getResourceLoader(), coreContainer, core, solrMetricsContext.tag,
+        SolrInfoBean.Group.core, solrMetricsContext.registry);
     if (cloudMode) {
       metricManager.loadShardReporters(pluginInfos, core);
     }
@@ -99,19 +98,20 @@
    * This method also reloads reporters so that they use the new core name.
    */
   public void afterCoreSetName() {
-    String oldRegistryName = registryName;
+    String oldRegistryName = solrMetricsContext.registry;
     String oldLeaderRegistryName = leaderRegistryName;
     initCloudMode();
-    registryName = createRegistryName(cloudMode, collectionName, shardName, replicaName, core.getName());
+    String newRegistryName = createRegistryName(cloudMode, collectionName, shardName, replicaName, core.getName());
     leaderRegistryName = createLeaderRegistryName(cloudMode, collectionName, shardName);
-    if (oldRegistryName.equals(registryName)) {
+    if (oldRegistryName.equals(newRegistryName)) {
       return;
     }
     // close old reporters
-    metricManager.closeReporters(oldRegistryName, tag);
+    metricManager.closeReporters(oldRegistryName, solrMetricsContext.tag);
     if (oldLeaderRegistryName != null) {
-      metricManager.closeReporters(oldLeaderRegistryName, tag);
+      metricManager.closeReporters(oldLeaderRegistryName, solrMetricsContext.tag);
     }
+    solrMetricsContext = new SolrMetricsContext(metricManager, newRegistryName, solrMetricsContext.tag);
     // load reporters again, using the new core name
     loadReporters();
   }
@@ -127,15 +127,16 @@
       throw new IllegalArgumentException("registerMetricProducer() called with illegal arguments: " +
           "scope = " + scope + ", producer = " + producer);
     }
-    producer.initializeMetrics(metricManager, getRegistryName(), tag, scope);
+    // use deprecated method for back-compat, remove in 9.0
+    producer.initializeMetrics(solrMetricsContext.metricManager, solrMetricsContext.registry, solrMetricsContext.tag, scope);
   }
 
   /**
    * Return the registry used by this SolrCore.
    */
   public MetricRegistry getRegistry() {
-    if (registryName != null) {
-      return metricManager.registry(registryName);
+    if (solrMetricsContext != null) {
+      return solrMetricsContext.getMetricRegistry();
     } else {
       return null;
     }
@@ -146,11 +147,15 @@
    */
   @Override
   public void close() throws IOException {
-    metricManager.closeReporters(getRegistryName(), tag);
+    metricManager.closeReporters(solrMetricsContext.registry, solrMetricsContext.tag);
     if (getLeaderRegistryName() != null) {
-      metricManager.closeReporters(getLeaderRegistryName(), tag);
+      metricManager.closeReporters(getLeaderRegistryName(), solrMetricsContext.tag);
     }
-    metricManager.unregisterGauges(getRegistryName(), tag);
+    metricManager.unregisterGauges(solrMetricsContext.registry, solrMetricsContext.tag);
+  }
+
+  public SolrMetricsContext getSolrMetricsContext() {
+    return solrMetricsContext;
   }
 
   public SolrCore getCore() {
@@ -175,7 +180,7 @@
    * @return the metric registry name of the manager.
    */
   public String getRegistryName() {
-    return registryName;
+    return solrMetricsContext != null ? solrMetricsContext.registry : null;
   }
 
   /**
@@ -190,7 +195,7 @@
    * Return a tag specific to this instance.
    */
   public String getTag() {
-    return tag;
+    return solrMetricsContext.tag;
   }
 
   public static String createRegistryName(boolean cloud, String collectionName, String shardName, String replicaName, String coreName) {
diff --git a/solr/core/src/java/org/apache/solr/metrics/SolrMetricManager.java b/solr/core/src/java/org/apache/solr/metrics/SolrMetricManager.java
index 7d2877d..977b0ca 100644
--- a/solr/core/src/java/org/apache/solr/metrics/SolrMetricManager.java
+++ b/solr/core/src/java/org/apache/solr/metrics/SolrMetricManager.java
@@ -724,20 +724,24 @@
     registerMetric(info, registry, new GaugeWrapper(gauge, tag), force, metricName, metricPath);
   }
 
-  public int unregisterGauges(String registryName, String tag) {
-    if (tag == null) {
+  public int unregisterGauges(String registryName, String tagSegment) {
+    if (tagSegment == null) {
       return 0;
     }
     MetricRegistry registry = registry(registryName);
+    if (registry == null) return 0;
     AtomicInteger removed = new AtomicInteger();
     registry.removeMatching((name, metric) -> {
-      if (metric instanceof GaugeWrapper &&
-          tag.equals(((GaugeWrapper) metric).getTag())) {
-        removed.incrementAndGet();
-        return true;
-      } else {
-        return false;
+      if (metric instanceof GaugeWrapper) {
+        GaugeWrapper wrapper = (GaugeWrapper) metric;
+        boolean toRemove = wrapper.getTag().contains(tagSegment);
+        if (toRemove) {
+          removed.incrementAndGet();
+        }
+        return toRemove;
       }
+      return false;
+
     });
     return removed.get();
   }
@@ -752,10 +756,16 @@
    * segments prepended to the name.
    */
   public static String mkName(String name, String... path) {
+    return makeName(path == null || path.length == 0 ? Collections.emptyList() : Arrays.asList(path),
+        name);
+
+  }
+
+  public static String makeName(List<String> path, String name) {
     if (name == null || name.isEmpty()) {
       throw new IllegalArgumentException("name must not be empty");
     }
-    if (path == null || path.length == 0) {
+    if (path == null || path.size() == 0) {
       return name;
     } else {
       StringBuilder sb = new StringBuilder();
diff --git a/solr/core/src/java/org/apache/solr/metrics/SolrMetricProducer.java b/solr/core/src/java/org/apache/solr/metrics/SolrMetricProducer.java
index 265d7e4..29c14ce 100644
--- a/solr/core/src/java/org/apache/solr/metrics/SolrMetricProducer.java
+++ b/solr/core/src/java/org/apache/solr/metrics/SolrMetricProducer.java
@@ -19,17 +19,83 @@
 /**
  * Used by objects that expose metrics through {@link SolrMetricManager}.
  */
-public interface SolrMetricProducer {
+public interface SolrMetricProducer extends AutoCloseable {
+
+  /**
+   * Unique metric tag identifies components with the same life-cycle, which should
+   * be registered / unregistered together. It is in the format of A:B:C, where
+   * A is the parent of B is the parent of C and so on.
+   * If object "B" is unregistered C also must get unregistered.
+   * If object "A" is unregistered B and C also must get unregistered.
+   * @param o object to create a tag for
+   * @param parentName parent object name, or null if no parent exists
+   */
+  static String getUniqueMetricTag(Object o, String parentName) {
+    String name = o.getClass().getSimpleName() + "@" + Integer.toHexString(o.hashCode());
+    if (parentName != null && parentName.contains(name)) {
+      throw new RuntimeException("Parent already includes this component! parent=" + parentName + ", this=" + name);
+    }
+    return parentName == null ?
+        name :
+        parentName + ":" + name;
+  }
 
   /**
    * Initializes metrics specific to this producer
-   * @param manager an instance of {@link SolrMetricManager}
+   *
+   * @param manager  an instance of {@link SolrMetricManager}
    * @param registry registry name where metrics are registered
-   * @param tag a symbolic tag that represents this instance of the producer,
-   * or a group of related instances that have the same life-cycle. This tag is
-   * used when managing life-cycle of some metrics and is set when
-   * {@link #initializeMetrics(SolrMetricManager, String, String, String)} is called.
-   * @param scope scope of the metrics (eg. handler name) to separate metrics of
+   * @param tag      a symbolic tag that represents this instance of the producer,
+   *                 or a group of related instances that have the same life-cycle. This tag is
+   *                 used when managing life-cycle of some metrics.
+   * @param scope    scope of the metrics (eg. handler name) to separate metrics of components with
+   *                 the same implementation but different scope.
+   * @deprecated use {@link #initializeMetrics(SolrMetricsContext, String)} instead
    */
-  void initializeMetrics(SolrMetricManager manager, String registry, String tag, String scope);
+  @Deprecated
+  default void initializeMetrics(SolrMetricManager manager, String registry, String tag, String scope) {
+    initializeMetrics(new SolrMetricsContext(manager, registry, tag), scope);
+
+  }
+
+  /**
+   * Initialize metrics specific to this producer.
+   * @param parentContext parent metrics context. If this component has the same life-cycle as the parent
+   *                it can simply use the parent context, otherwise it should obtain a child context
+   *                using {@link SolrMetricsContext#getChildContext(Object)} passing <code>this</code>
+   *                as the child.
+   * @param scope component scope
+   */
+  default void initializeMetrics(SolrMetricsContext parentContext, String scope) {
+    throw new RuntimeException("In class " + getClass().getName() +
+        " you must implement either initializeMetrics(SolrMetricsContext, String) or " +
+        "initializeMetrics(SolrMetricManager, String, String, String)");
+
+  }
+
+  /**
+   * Implementing classes should override this method to provide the context obtained in
+   * {@link #initializeMetrics(SolrMetricsContext, String)} to ensure proper cleanup of metrics
+   * at the end of the life-cycle of this component.
+   */
+  default SolrMetricsContext getSolrMetricsContext() {
+    return null;
+  }
+
+  /**
+   * Implementations should always call <code>SolrMetricProducer.super.close()</code> to ensure that
+   * metrics with the same life-cycle as this component are properly unregistered. This prevents
+   * obscure memory leaks.
+   */
+  @Override
+  default void close() throws Exception {
+    SolrMetricsContext context = getSolrMetricsContext();
+    if (context == null) {
+      return;
+    } else {
+      context.unregister();
+    }
+    // ??? (ab) no idea what this was supposed to avoid
+    //if (info == null || info.tag.indexOf(':') == -1) return;//this will end up unregistering the root itself
+  }
 }
diff --git a/solr/core/src/java/org/apache/solr/metrics/SolrMetricsContext.java b/solr/core/src/java/org/apache/solr/metrics/SolrMetricsContext.java
new file mode 100644
index 0000000..dd37e1f
--- /dev/null
+++ b/solr/core/src/java/org/apache/solr/metrics/SolrMetricsContext.java
@@ -0,0 +1,114 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.apache.solr.metrics;
+
+import com.codahale.metrics.Counter;
+import com.codahale.metrics.Gauge;
+import com.codahale.metrics.Histogram;
+import com.codahale.metrics.Meter;
+import com.codahale.metrics.MetricRegistry;
+import com.codahale.metrics.Timer;
+import org.apache.solr.core.SolrInfoBean;
+
+/**
+ * This class represents a metrics context that ties together components with the same life-cycle
+ * and provides convenient access to the metric registry.
+ */
+public class SolrMetricsContext {
+  public final String registry;
+  public final SolrMetricManager metricManager;
+  public final String tag;
+
+  public SolrMetricsContext(SolrMetricManager metricManager, String registry, String tag) {
+    this.registry = registry;
+    this.metricManager = metricManager;
+    this.tag = tag;
+  }
+
+  /**
+   * Metrics tag that represents objects with the same life-cycle.
+   */
+  public String getTag() {
+    return tag;
+  }
+
+  /**
+   * Unregister all {@link Gauge} metrics that use this context's tag.
+   *
+   * <p><b>NOTE: This method MUST be called at the end of a life-cycle (typically in <code>close()</code>)
+   * of components that register gauge metrics with references to the current object's instance. Failure to
+   * do so may result in hard-to-debug memory leaks.</b></p>
+   */
+  public void unregister() {
+    metricManager.unregisterGauges(registry, tag);
+  }
+
+  /**
+   * Get a context with the same registry name but a tag that represents a parent-child relationship.
+   * Since it's a different tag than the parent's context it is assumed that the life-cycle of the parent
+   * and child are different.
+   * @param child child object that produces metrics with a different life-cycle than the parent.
+   */
+  public SolrMetricsContext getChildContext(Object child) {
+    SolrMetricsContext childContext = new SolrMetricsContext(metricManager, registry, SolrMetricProducer.getUniqueMetricTag(child, tag));
+    return childContext;
+  }
+
+  /**
+   * Convenience method for {@link SolrMetricManager#meter(SolrInfoBean, String, String, String...)}.
+   */
+  public Meter meter(SolrInfoBean info, String metricName, String... metricPath) {
+    return metricManager.meter(info, registry, metricName, metricPath);
+  }
+
+  /**
+   * Convenience method for {@link SolrMetricManager#counter(SolrInfoBean, String, String, String...)}.
+   */
+  public Counter counter(SolrInfoBean info, String metricName, String... metricPath) {
+    return metricManager.counter(info, registry, metricName, metricPath);
+
+  }
+
+  /**
+   * Convenience method for {@link SolrMetricManager#registerGauge(SolrInfoBean, String, Gauge, String, boolean, String, String...)}.
+   */
+  public void gauge(SolrInfoBean info, Gauge<?> gauge, boolean force, String metricName, String... metricPath) {
+    metricManager.registerGauge(info, registry, gauge, tag, force, metricName, metricPath);
+  }
+
+  /**
+   * Convenience method for {@link SolrMetricManager#meter(SolrInfoBean, String, String, String...)}.
+   */
+  public Timer timer(SolrInfoBean info, String metricName, String... metricPath) {
+    return metricManager.timer(info, registry, metricName, metricPath);
+  }
+
+  /**
+   * Convenience method for {@link SolrMetricManager#histogram(SolrInfoBean, String, String, String...)}.
+   */
+  public Histogram histogram(SolrInfoBean info, String metricName, String... metricPath) {
+    return metricManager.histogram(info, registry, metricName, metricPath);
+  }
+
+  /**
+   * Get the MetricRegistry instance that is used for registering metrics in this context.
+   */
+  public MetricRegistry getMetricRegistry() {
+    return metricManager.registry(registry);
+  }
+}
diff --git a/solr/core/src/java/org/apache/solr/search/CaffeineCache.java b/solr/core/src/java/org/apache/solr/search/CaffeineCache.java
index 71eb86f..f3c4c66 100644
--- a/solr/core/src/java/org/apache/solr/search/CaffeineCache.java
+++ b/solr/core/src/java/org/apache/solr/search/CaffeineCache.java
@@ -31,14 +31,13 @@
 import java.util.concurrent.TimeUnit;
 import java.util.concurrent.atomic.LongAdder;
 
-import com.codahale.metrics.MetricRegistry;
 import com.github.benmanes.caffeine.cache.RemovalCause;
 import com.github.benmanes.caffeine.cache.RemovalListener;
 import org.apache.lucene.util.Accountable;
 import org.apache.lucene.util.RamUsageEstimator;
 import org.apache.solr.common.SolrException;
 import org.apache.solr.metrics.MetricsMap;
-import org.apache.solr.metrics.SolrMetricManager;
+import org.apache.solr.metrics.SolrMetricsContext;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
@@ -88,7 +87,7 @@
 
   private Set<String> metricNames = ConcurrentHashMap.newKeySet();
   private MetricsMap cacheMap;
-  private MetricRegistry registry;
+  private SolrMetricsContext solrMetricsContext;
 
   private long initialRamBytes = 0;
   private final LongAdder ramBytes = new LongAdder();
@@ -202,7 +201,8 @@
   }
 
   @Override
-  public void close() {
+  public void close() throws Exception {
+    SolrCache.super.close();
     cache.invalidateAll();
     cache.cleanUp();
     if (executor instanceof ExecutorService) {
@@ -322,8 +322,8 @@
   }
 
   @Override
-  public MetricRegistry getMetricRegistry() {
-    return registry;
+  public SolrMetricsContext getSolrMetricsContext() {
+    return solrMetricsContext;
   }
 
   @Override
@@ -337,8 +337,8 @@
   }
 
   @Override
-  public void initializeMetrics(SolrMetricManager manager, String registryName, String tag, String scope) {
-    registry = manager.registry(registryName);
+  public void initializeMetrics(SolrMetricsContext parentContext, String scope) {
+    solrMetricsContext = parentContext.getChildContext(this);
     cacheMap = new MetricsMap((detailed, map) -> {
       if (cache != null) {
         CacheStats stats = cache.stats();
@@ -362,6 +362,6 @@
         map.put("cumulative_evictions", cumulativeStats.evictionCount());
       }
     });
-    manager.registerGauge(this, registryName, cacheMap, tag, true, scope, getCategory().toString());
+    solrMetricsContext.gauge(this, cacheMap, true, scope, getCategory().toString());
   }
 }
diff --git a/solr/core/src/java/org/apache/solr/search/FastLRUCache.java b/solr/core/src/java/org/apache/solr/search/FastLRUCache.java
index 2dc1c1e..b74b63f 100644
--- a/solr/core/src/java/org/apache/solr/search/FastLRUCache.java
+++ b/solr/core/src/java/org/apache/solr/search/FastLRUCache.java
@@ -16,24 +16,23 @@
  */
 package org.apache.solr.search;
 
-import com.codahale.metrics.MetricRegistry;
+import java.lang.invoke.MethodHandles;
+import java.util.List;
+import java.util.Map;
+import java.util.Set;
+import java.util.concurrent.ConcurrentHashMap;
+import java.util.concurrent.CopyOnWriteArrayList;
+import java.util.concurrent.TimeUnit;
+
 import org.apache.lucene.util.Accountable;
 import org.apache.lucene.util.RamUsageEstimator;
 import org.apache.solr.common.SolrException;
 import org.apache.solr.metrics.MetricsMap;
-import org.apache.solr.metrics.SolrMetricManager;
+import org.apache.solr.metrics.SolrMetricsContext;
 import org.apache.solr.util.ConcurrentLRUCache;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
-import java.lang.invoke.MethodHandles;
-import java.util.concurrent.ConcurrentHashMap;
-import java.util.List;
-import java.util.Map;
-import java.util.Set;
-import java.util.concurrent.CopyOnWriteArrayList;
-import java.util.concurrent.TimeUnit;
-
 /**
  * SolrCache based on ConcurrentLRUCache implementation.
  * <p>
@@ -42,12 +41,11 @@
  * <p>
  * Also see <a href="http://wiki.apache.org/solr/SolrCaching">SolrCaching</a>
  *
- *
  * @see org.apache.solr.util.ConcurrentLRUCache
  * @see org.apache.solr.search.SolrCache
  * @since solr 1.4
  */
-public class FastLRUCache<K, V> extends SolrCacheBase implements SolrCache<K,V>, Accountable {
+public class FastLRUCache<K, V> extends SolrCacheBase implements SolrCache<K, V>, Accountable {
   private static final Logger log = LoggerFactory.getLogger(MethodHandles.lookup().lookupClass());
 
   private static final long BASE_RAM_BYTES_USED = RamUsageEstimator.shallowSizeOfInstance(FastLRUCache.class);
@@ -61,7 +59,7 @@
   private long warmupTime = 0;
 
   private String description = "Concurrent LRU Cache";
-  private ConcurrentLRUCache<K,V> cache;
+  private ConcurrentLRUCache<K, V> cache;
   private int showItems = 0;
 
   private long maxRamBytes;
@@ -75,7 +73,7 @@
 
   private MetricsMap cacheMap;
   private Set<String> metricNames = ConcurrentHashMap.newKeySet();
-  private MetricRegistry registry;
+  private SolrMetricsContext solrMetricsContext;
 
   @Override
   public Object init(Map args, Object persistence, CacheRegenerator regenerator) {
@@ -117,7 +115,7 @@
     str = (String) args.get(MAX_RAM_MB_PARAM);
     long maxRamMB = str == null ? -1 : (long) Double.parseDouble(str);
     this.maxRamBytes = maxRamMB < 0 ? Long.MAX_VALUE : maxRamMB * 1024L * 1024L;
-    if (maxRamBytes != Long.MAX_VALUE)  {
+    if (maxRamBytes != Long.MAX_VALUE) {
       ramLowerWatermark = Math.round(maxRamBytes * 0.8);
       description = generateDescription(maxRamBytes, ramLowerWatermark, cleanupThread);
       cache = new ConcurrentLRUCache<>(ramLowerWatermark, maxRamBytes, cleanupThread, null, maxIdleTimeSec);
@@ -213,7 +211,7 @@
    */
   protected String generateDescription(int limit, int initialSize, int minLimit, int acceptableLimit, boolean newThread) {
     String description = "Concurrent LRU Cache(maxSize=" + limit + ", initialSize=" + initialSize +
-        ", minSize="+minLimit + ", acceptableSize="+acceptableLimit+", cleanupThread="+newThread;
+        ", minSize=" + minLimit + ", acceptableSize=" + acceptableLimit + ", cleanupThread=" + newThread;
     if (isAutowarmingOn()) {
       description += ", " + getAutowarmDescription();
     }
@@ -274,10 +272,9 @@
       for (int i = itemsArr.length - 1; i >= 0; i--) {
         try {
           boolean continueRegen = regenerator.regenerateItem(searcher,
-                  this, old, itemsArr[i].getKey(), itemsArr[i].getValue());
+              this, old, itemsArr[i].getKey(), itemsArr[i].getValue());
           if (!continueRegen) break;
-        }
-        catch (Exception e) {
+        } catch (Exception e) {
           SolrException.log(log, "Error during auto-warming of key:" + itemsArr[i].getKey(), e);
         }
       }
@@ -287,7 +284,8 @@
 
 
   @Override
-  public void close() {
+  public void close() throws Exception {
+    SolrCache.super.close();
     // add the stats to the cumulative stats object (the first in the statsList)
     statsList.get(0).add(cache.getStats());
     statsList.remove(cache.getStats());
@@ -310,10 +308,16 @@
     return metricNames;
   }
 
+
   @Override
-  public void initializeMetrics(SolrMetricManager manager, String registryName, String tag, String scope) {
-    registry = manager.registry(registryName);
-    manager.registerGauge(this, registryName, cacheMap, tag, true, scope, getCategory().toString());
+  public SolrMetricsContext getSolrMetricsContext() {
+    return solrMetricsContext;
+  }
+
+  @Override
+  public void initializeMetrics(SolrMetricsContext parentContext, String scope) {
+    this.solrMetricsContext = parentContext.getChildContext(this);
+    this.solrMetricsContext.gauge(this, cacheMap, true, scope, getCategory().toString());
   }
 
   // for unit tests only
@@ -322,11 +326,6 @@
   }
 
   @Override
-  public MetricRegistry getMetricRegistry() {
-    return registry;
-  }
-
-  @Override
   public String toString() {
     return name() + (cacheMap != null ? cacheMap.getValue().toString() : "");
   }
diff --git a/solr/core/src/java/org/apache/solr/search/LFUCache.java b/solr/core/src/java/org/apache/solr/search/LFUCache.java
index 20cf664..125f08a 100644
--- a/solr/core/src/java/org/apache/solr/search/LFUCache.java
+++ b/solr/core/src/java/org/apache/solr/search/LFUCache.java
@@ -17,19 +17,18 @@
 package org.apache.solr.search;
 
 import java.lang.invoke.MethodHandles;
-import java.util.concurrent.ConcurrentHashMap;
 import java.util.List;
 import java.util.Map;
 import java.util.Set;
+import java.util.concurrent.ConcurrentHashMap;
 import java.util.concurrent.CopyOnWriteArrayList;
 import java.util.concurrent.TimeUnit;
 
-import com.codahale.metrics.MetricRegistry;
 import org.apache.lucene.util.Accountable;
 import org.apache.lucene.util.RamUsageEstimator;
 import org.apache.solr.common.SolrException;
 import org.apache.solr.metrics.MetricsMap;
-import org.apache.solr.metrics.SolrMetricManager;
+import org.apache.solr.metrics.SolrMetricsContext;
 import org.apache.solr.util.ConcurrentLFUCache;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
@@ -79,7 +78,8 @@
   private int maxIdleTimeSec;
   private MetricsMap cacheMap;
   private Set<String> metricNames = ConcurrentHashMap.newKeySet();
-  private MetricRegistry registry;
+  private SolrMetricsContext solrMetricsContext;
+
 
   private int maxSize;
   private int minSizeLimit;
@@ -230,7 +230,8 @@
 
 
   @Override
-  public void close() {
+  public void close() throws Exception {
+    SolrCache.super.close();
     // add the stats to the cumulative stats object (the first in the statsList)
     statsList.get(0).add(cache.getStats());
     statsList.remove(cache.getStats());
@@ -263,8 +264,13 @@
   }
 
   @Override
-  public void initializeMetrics(SolrMetricManager manager, String registryName, String tag, String scope) {
-    registry = manager.registry(registryName);
+  public SolrMetricsContext getSolrMetricsContext() {
+    return solrMetricsContext;
+  }
+
+  @Override
+  public void initializeMetrics(SolrMetricsContext parentContext, String scope) {
+    solrMetricsContext = parentContext.getChildContext(this);
     cacheMap = new MetricsMap((detailed, map) -> {
       if (cache != null) {
         ConcurrentLFUCache.Stats stats = cache.getStats();
@@ -330,7 +336,7 @@
 
       }
     });
-    manager.registerGauge(this, registryName, cacheMap, tag, true, scope, getCategory().toString());
+    solrMetricsContext.gauge(this, cacheMap, true, scope, getCategory().toString());
   }
 
   // for unit tests only
@@ -344,11 +350,6 @@
   }
 
   @Override
-  public MetricRegistry getMetricRegistry() {
-    return registry;
-  }
-
-  @Override
   public String toString() {
     return name + (cacheMap != null ? cacheMap.getValue().toString() : "");
   }
diff --git a/solr/core/src/java/org/apache/solr/search/LRUCache.java b/solr/core/src/java/org/apache/solr/search/LRUCache.java
index c733c07..7a1b37c 100644
--- a/solr/core/src/java/org/apache/solr/search/LRUCache.java
+++ b/solr/core/src/java/org/apache/solr/search/LRUCache.java
@@ -18,22 +18,21 @@
 
 import java.lang.invoke.MethodHandles;
 import java.util.Collection;
-import java.util.concurrent.ConcurrentHashMap;
 import java.util.Iterator;
 import java.util.LinkedHashMap;
 import java.util.Map;
 import java.util.Set;
+import java.util.concurrent.ConcurrentHashMap;
 import java.util.concurrent.TimeUnit;
 import java.util.concurrent.atomic.LongAdder;
 
-import com.codahale.metrics.MetricRegistry;
 import org.apache.lucene.util.Accountable;
 import org.apache.lucene.util.Accountables;
 import org.apache.lucene.util.RamUsageEstimator;
 import org.apache.solr.common.SolrException;
 import org.apache.solr.common.util.TimeSource;
 import org.apache.solr.metrics.MetricsMap;
-import org.apache.solr.metrics.SolrMetricManager;
+import org.apache.solr.metrics.SolrMetricsContext;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
@@ -77,7 +76,7 @@
   private String description="LRU Cache";
   private MetricsMap cacheMap;
   private Set<String> metricNames = ConcurrentHashMap.newKeySet();
-  private MetricRegistry registry;
+  private SolrMetricsContext solrMetricsContext;
   private int maxSize;
   private int initialSize;
 
@@ -234,8 +233,8 @@
   }
 
   /**
-   * 
-   * @return Returns the description of this cache. 
+   *
+   * @return Returns the description of this cache.
    */
   private String generateDescription() {
     String description = "LRU Cache(maxSize=" + getMaxSize() + ", initialSize=" + initialSize;
@@ -341,9 +340,9 @@
 
       // Don't do the autowarming in the synchronized block, just pull out the keys and values.
       synchronized (other.map) {
-        
+
         int sz = autowarm.getWarmCount(other.map.size());
-        
+
         keys = new Object[sz];
         vals = new Object[sz];
 
@@ -378,12 +377,6 @@
     warmupTime = TimeUnit.MILLISECONDS.convert(System.nanoTime() - warmingStartTime, TimeUnit.NANOSECONDS);
   }
 
-  @Override
-  public void close() {
-
-  }
-
-
   //////////////////////// SolrInfoMBeans methods //////////////////////
 
 
@@ -403,8 +396,13 @@
   }
 
   @Override
-  public void initializeMetrics(SolrMetricManager manager, String registryName, String tag, String scope) {
-    registry = manager.registry(registryName);
+  public SolrMetricsContext getSolrMetricsContext() {
+    return solrMetricsContext;
+  }
+
+  @Override
+  public void initializeMetrics(SolrMetricsContext parentContext, String scope) {
+    solrMetricsContext = parentContext.getChildContext(this);
     cacheMap = new MetricsMap((detailed, res) -> {
       synchronized (map) {
         res.put(LOOKUPS_PARAM, lookups);
@@ -433,7 +431,7 @@
       res.put("cumulative_evictionsRamUsage", stats.evictionsRamUsage.longValue());
       res.put("cumulative_evictionsIdleTime", stats.evictionsIdleTime.longValue());
     });
-    manager.registerGauge(this, registryName, cacheMap, tag, true, scope, getCategory().toString());
+    solrMetricsContext.gauge(this, cacheMap, true, scope, getCategory().toString());
   }
 
   // for unit tests only
@@ -442,11 +440,6 @@
   }
 
   @Override
-  public MetricRegistry getMetricRegistry() {
-    return registry;
-  }
-
-  @Override
   public String toString() {
     return name() + (cacheMap != null ? cacheMap.getValue().toString() : "");
   }
diff --git a/solr/core/src/java/org/apache/solr/search/SolrCache.java b/solr/core/src/java/org/apache/solr/search/SolrCache.java
index 4a16b39..55f57ec 100644
--- a/solr/core/src/java/org/apache/solr/search/SolrCache.java
+++ b/solr/core/src/java/org/apache/solr/search/SolrCache.java
@@ -137,7 +137,9 @@
 
 
   /** Frees any non-memory resources */
-  public void close();
+  default void close() throws Exception {
+    SolrMetricProducer.super.close();
+  }
 
   /** Returns maximum size limit (number of items) if set and supported, -1 otherwise. */
   int getMaxSize();
diff --git a/solr/core/src/java/org/apache/solr/search/SolrCacheHolder.java b/solr/core/src/java/org/apache/solr/search/SolrCacheHolder.java
index 66b8ab1..7afe96d 100644
--- a/solr/core/src/java/org/apache/solr/search/SolrCacheHolder.java
+++ b/solr/core/src/java/org/apache/solr/search/SolrCacheHolder.java
@@ -22,8 +22,7 @@
 import java.util.Set;
 
 import com.codahale.metrics.MetricRegistry;
-import org.apache.solr.common.util.Utils;
-import org.apache.solr.metrics.SolrMetricManager;
+import org.apache.solr.metrics.SolrMetricsContext;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
@@ -77,7 +76,7 @@
     return delegate;
   }
 
-  public void close() {
+  public void close() throws Exception {
     delegate.close();
   }
 
@@ -142,11 +141,8 @@
   }
 
   @Override
-  public void initializeMetrics(SolrMetricManager manager, String registry, String tag, String scope) {
-    log.debug("Going to register cachemetrics " + Utils.toJSONString(factory));
-
-    delegate.initializeMetrics(manager, registry, tag,scope);
-
+  public void initializeMetrics(SolrMetricsContext parentContext, String scope) {
+    delegate.initializeMetrics(parentContext, scope);
   }
 
 }
diff --git a/solr/core/src/java/org/apache/solr/search/SolrFieldCacheBean.java b/solr/core/src/java/org/apache/solr/search/SolrFieldCacheBean.java
index b2647cd..b6deb7c 100644
--- a/solr/core/src/java/org/apache/solr/search/SolrFieldCacheBean.java
+++ b/solr/core/src/java/org/apache/solr/search/SolrFieldCacheBean.java
@@ -19,11 +19,10 @@
 import java.util.Set;
 import java.util.concurrent.ConcurrentHashMap;
 
-import com.codahale.metrics.MetricRegistry;
 import org.apache.solr.core.SolrInfoBean;
 import org.apache.solr.metrics.MetricsMap;
-import org.apache.solr.metrics.SolrMetricManager;
 import org.apache.solr.metrics.SolrMetricProducer;
+import org.apache.solr.metrics.SolrMetricsContext;
 import org.apache.solr.uninverting.UninvertingReader;
 
 /**
@@ -35,7 +34,7 @@
   private boolean disableEntryList = Boolean.getBoolean("disableSolrFieldCacheMBeanEntryList");
   private boolean disableJmxEntryList = Boolean.getBoolean("disableSolrFieldCacheMBeanEntryListJmx");
 
-  private MetricRegistry registry;
+  private SolrMetricsContext solrMetricsContext;
   private Set<String> metricNames = ConcurrentHashMap.newKeySet();
 
   @Override
@@ -50,14 +49,15 @@
   public Set<String> getMetricNames() {
     return metricNames;
   }
+
   @Override
-  public MetricRegistry getMetricRegistry() {
-    return registry;
+  public SolrMetricsContext getSolrMetricsContext() {
+    return solrMetricsContext;
   }
 
   @Override
-  public void initializeMetrics(SolrMetricManager manager, String registryName, String tag, String scope) {
-    registry = manager.registry(registryName);
+  public void initializeMetrics(SolrMetricsContext parentContext, String scope) {
+    this.solrMetricsContext = parentContext;
     MetricsMap metricsMap = new MetricsMap((detailed, map) -> {
       if (detailed && !disableEntryList && !disableJmxEntryList) {
         UninvertingReader.FieldCacheStats fieldCacheStats = UninvertingReader.getUninvertedStats();
@@ -72,6 +72,6 @@
         map.put("entries_count", UninvertingReader.getUninvertedStatsSize());
       }
     });
-    manager.registerGauge(this, registryName, metricsMap, tag, true, "fieldCache", Category.CACHE.toString(), scope);
+    solrMetricsContext.gauge(this, metricsMap, true, "fieldCache", Category.CACHE.toString(), scope);
   }
 }
diff --git a/solr/core/src/java/org/apache/solr/search/SolrIndexSearcher.java b/solr/core/src/java/org/apache/solr/search/SolrIndexSearcher.java
index 7d33a19..a831b45 100644
--- a/solr/core/src/java/org/apache/solr/search/SolrIndexSearcher.java
+++ b/solr/core/src/java/org/apache/solr/search/SolrIndexSearcher.java
@@ -35,7 +35,6 @@
 import java.util.concurrent.atomic.AtomicLong;
 import java.util.concurrent.atomic.AtomicReference;
 
-import com.codahale.metrics.MetricRegistry;
 import com.google.common.collect.Iterables;
 import org.apache.lucene.document.Document;
 import org.apache.lucene.index.DirectoryReader;
@@ -69,6 +68,7 @@
 import org.apache.solr.metrics.MetricsMap;
 import org.apache.solr.metrics.SolrMetricManager;
 import org.apache.solr.metrics.SolrMetricProducer;
+import org.apache.solr.metrics.SolrMetricsContext;
 import org.apache.solr.request.LocalSolrQueryRequest;
 import org.apache.solr.request.SolrQueryRequest;
 import org.apache.solr.request.SolrRequestInfo;
@@ -140,8 +140,7 @@
   private final StatsCache statsCache;
 
   private Set<String> metricNames = ConcurrentHashMap.newKeySet();
-  private SolrMetricManager metricManager;
-  private String registryName;
+  private SolrMetricsContext solrMetricsContext;
 
   private static DirectoryReader getReader(SolrCore core, SolrIndexConfig config, DirectoryFactory directoryFactory,
                                            String path) throws IOException {
@@ -431,12 +430,13 @@
       cache.setState(SolrCache.State.LIVE);
       infoRegistry.put(cache.name(), cache);
     }
-    metricManager = core.getCoreContainer().getMetricManager();
-    registryName = core.getCoreMetricManager().getRegistryName();
+    this.solrMetricsContext = core.getSolrMetricsContext().getChildContext(this);
     for (SolrCache cache : cacheList) {
-      cache.initializeMetrics(metricManager, registryName, core.getMetricTag(), SolrMetricManager.mkName(cache.name(), STATISTICS_KEY));
+      // XXX use the deprecated method for back-compat. remove in 9.0
+      cache.initializeMetrics(solrMetricsContext.metricManager,
+          solrMetricsContext.registry, solrMetricsContext.tag, SolrMetricManager.mkName(cache.name(), STATISTICS_KEY));
     }
-    initializeMetrics(metricManager, registryName, core.getMetricTag(), STATISTICS_KEY);
+    initializeMetrics(solrMetricsContext, STATISTICS_KEY);
     registerTime = new Date();
   }
 
@@ -479,7 +479,11 @@
     }
 
     for (SolrCache cache : cacheList) {
-      cache.close();
+      try {
+        cache.close();
+      } catch (Exception e) {
+        SolrException.log(log, "Exception closing cache " + cache.name(), e);
+      }
     }
 
     if (releaseDirectory) {
@@ -2275,23 +2279,26 @@
   }
 
   @Override
-  public void initializeMetrics(SolrMetricManager manager, String registry, String tag, String scope) {
-    this.registryName = registry;
-    this.metricManager = manager;
-    manager.registerGauge(this, registry, () -> name, tag, true, "searcherName", Category.SEARCHER.toString(), scope);
-    manager.registerGauge(this, registry, () -> cachingEnabled, tag, true, "caching", Category.SEARCHER.toString(), scope);
-    manager.registerGauge(this, registry, () -> openTime, tag, true, "openedAt", Category.SEARCHER.toString(), scope);
-    manager.registerGauge(this, registry, () -> warmupTime, tag, true, "warmupTime", Category.SEARCHER.toString(), scope);
-    manager.registerGauge(this, registry, () -> registerTime, tag, true, "registeredAt", Category.SEARCHER.toString(), scope);
+  public SolrMetricsContext getSolrMetricsContext() {
+    return solrMetricsContext;
+  }
+
+  @Override
+  public void initializeMetrics(SolrMetricsContext parentContext, String scope) {
+    parentContext.gauge(this, () -> name, true, "searcherName", Category.SEARCHER.toString(), scope);
+    parentContext.gauge(this, () -> cachingEnabled, true, "caching", Category.SEARCHER.toString(), scope);
+    parentContext.gauge(this, () -> openTime, true, "openedAt", Category.SEARCHER.toString(), scope);
+    parentContext.gauge(this, () -> warmupTime, true, "warmupTime", Category.SEARCHER.toString(), scope);
+    parentContext.gauge(this, () -> registerTime, true, "registeredAt", Category.SEARCHER.toString(), scope);
     // reader stats
-    manager.registerGauge(this, registry, () -> reader.numDocs(), tag, true, "numDocs", Category.SEARCHER.toString(), scope);
-    manager.registerGauge(this, registry, () -> reader.maxDoc(), tag, true, "maxDoc", Category.SEARCHER.toString(), scope);
-    manager.registerGauge(this, registry, () -> reader.maxDoc() - reader.numDocs(), tag, true, "deletedDocs", Category.SEARCHER.toString(), scope);
-    manager.registerGauge(this, registry, () -> reader.toString(), tag, true, "reader", Category.SEARCHER.toString(), scope);
-    manager.registerGauge(this, registry, () -> reader.directory().toString(), tag, true, "readerDir", Category.SEARCHER.toString(), scope);
-    manager.registerGauge(this, registry, () -> reader.getVersion(), tag, true, "indexVersion", Category.SEARCHER.toString(), scope);
+    parentContext.gauge(this, () -> reader.numDocs(), true, "numDocs", Category.SEARCHER.toString(), scope);
+    parentContext.gauge(this, () -> reader.maxDoc(), true, "maxDoc", Category.SEARCHER.toString(), scope);
+    parentContext.gauge(this, () -> reader.maxDoc() - reader.numDocs(), true, "deletedDocs", Category.SEARCHER.toString(), scope);
+    parentContext.gauge(this, () -> reader.toString(), true, "reader", Category.SEARCHER.toString(), scope);
+    parentContext.gauge(this, () -> reader.directory().toString(), true, "readerDir", Category.SEARCHER.toString(), scope);
+    parentContext.gauge(this, () -> reader.getVersion(), true, "indexVersion", Category.SEARCHER.toString(), scope);
     // size of the currently opened commit
-    manager.registerGauge(this, registry, () -> {
+    parentContext.gauge(this, () -> {
       try {
         Collection<String> files = reader.getIndexCommit().getFileNames();
         long total = 0;
@@ -2302,19 +2309,13 @@
       } catch (Exception e) {
         return -1;
       }
-    }, tag, true, "indexCommitSize", Category.SEARCHER.toString(), scope);
+    }, true, "indexCommitSize", Category.SEARCHER.toString(), scope);
     // statsCache metrics
-    manager.registerGauge(this, registry,
+    parentContext.gauge(this,
         new MetricsMap((detailed, map) -> {
           statsCache.getCacheMetrics().getSnapshot(map::put);
           map.put("statsCacheImpl", statsCache.getClass().getSimpleName());
-        }),
-        tag, true, "statsCache", Category.CACHE.toString(), scope);
-  }
-
-  @Override
-  public MetricRegistry getMetricRegistry() {
-    return core.getMetricRegistry();
+        }), true, "statsCache", Category.CACHE.toString(), scope);
   }
 
   private static class FilterImpl extends Filter {
diff --git a/solr/core/src/java/org/apache/solr/security/AuditLoggerPlugin.java b/solr/core/src/java/org/apache/solr/security/AuditLoggerPlugin.java
index a6c364a..d5ff666 100644
--- a/solr/core/src/java/org/apache/solr/security/AuditLoggerPlugin.java
+++ b/solr/core/src/java/org/apache/solr/security/AuditLoggerPlugin.java
@@ -36,7 +36,6 @@
 
 import com.codahale.metrics.Counter;
 import com.codahale.metrics.Meter;
-import com.codahale.metrics.MetricRegistry;
 import com.codahale.metrics.Timer;
 import com.fasterxml.jackson.annotation.JsonInclude.Include;
 import com.fasterxml.jackson.databind.ObjectMapper;
@@ -45,8 +44,8 @@
 import org.apache.solr.common.util.ExecutorUtil;
 import org.apache.solr.common.util.SolrjNamedThreadFactory;
 import org.apache.solr.core.SolrInfoBean;
-import org.apache.solr.metrics.SolrMetricManager;
 import org.apache.solr.metrics.SolrMetricProducer;
+import org.apache.solr.metrics.SolrMetricsContext;
 import org.apache.solr.security.AuditEvent.EventType;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
@@ -75,14 +74,12 @@
   int blockingQueueSize;
 
   protected AuditEventFormatter formatter;
-  private MetricRegistry registry;
   private Set<String> metricNames = ConcurrentHashMap.newKeySet();
   private ExecutorService executorService;
   private boolean closed;
   private MuteRules muteRules;
-  
-  protected String registryName;
-  protected SolrMetricManager metricManager;
+
+  protected SolrMetricsContext solrMetricsContext;
   protected Meter numErrors = new Meter();
   protected Meter numLost = new Meter();
   protected Meter numLogged = new Meter();
@@ -239,24 +236,21 @@
   }
   
   @Override
-  public void initializeMetrics(SolrMetricManager manager, String registryName, String tag, final String scope) {
+  public void initializeMetrics(SolrMetricsContext parentContext, final String scope) {
+    solrMetricsContext = parentContext.getChildContext(this);
     String className = this.getClass().getSimpleName();
     log.debug("Initializing metrics for {}", className);
-    this.metricManager = manager;
-    this.registryName = registryName;
-    // Metrics
-    registry = manager.registry(registryName);
-    numErrors = manager.meter(this, registryName, "errors", getCategory().toString(), scope, className);
-    numLost = manager.meter(this, registryName, "lost", getCategory().toString(), scope, className);
-    numLogged = manager.meter(this, registryName, "count", getCategory().toString(), scope, className);
-    requestTimes = manager.timer(this, registryName, "requestTimes", getCategory().toString(), scope, className);
-    totalTime = manager.counter(this, registryName, "totalTime", getCategory().toString(), scope, className);
+    numErrors = solrMetricsContext.meter(this, "errors", getCategory().toString(), scope, className);
+    numLost = solrMetricsContext.meter(this, "lost", getCategory().toString(), scope, className);
+    numLogged = solrMetricsContext.meter(this, "count", getCategory().toString(), scope, className);
+    requestTimes = solrMetricsContext.timer(this, "requestTimes", getCategory().toString(), scope, className);
+    totalTime = solrMetricsContext.counter(this, "totalTime", getCategory().toString(), scope, className);
     if (async) {
-      manager.registerGauge(this, registryName, () -> blockingQueueSize, "queueCapacity", true, "queueCapacity", getCategory().toString(), scope, className);
-      manager.registerGauge(this, registryName, () -> blockingQueueSize - queue.remainingCapacity(), "queueSize", true, "queueSize", getCategory().toString(), scope, className);
-      queuedTime = manager.timer(this, registryName, "queuedTime", getCategory().toString(), scope, className);
+      solrMetricsContext.gauge(this, () -> blockingQueueSize, true, "queueCapacity", getCategory().toString(), scope, className);
+      solrMetricsContext.gauge(this, () -> blockingQueueSize - queue.remainingCapacity(), true, "queueSize", getCategory().toString(), scope, className);
+      queuedTime = solrMetricsContext.timer(this, "queuedTime", getCategory().toString(), scope, className);
     }
-    manager.registerGauge(this, registryName, () -> async, "async", true, "async", getCategory().toString(), scope, className);
+    solrMetricsContext.gauge(this, () -> async, true, "async", getCategory().toString(), scope, className);
   }
   
   @Override
@@ -280,10 +274,10 @@
   }
 
   @Override
-  public MetricRegistry getMetricRegistry() {
-    return registry;
+  public SolrMetricsContext getSolrMetricsContext() {
+    return solrMetricsContext;
   }
-  
+
   /**
    * Interface for formatting the event
    */
@@ -325,6 +319,11 @@
       closed = true;
       log.info("Shutting down async Auditlogger background thread(s)");
       executorService.shutdownNow();
+      try {
+        SolrMetricProducer.super.close();
+      } catch (Exception e) {
+        throw new IOException("Exception closing", e);
+      }
     }
   }
 
diff --git a/solr/core/src/java/org/apache/solr/security/AuthenticationPlugin.java b/solr/core/src/java/org/apache/solr/security/AuthenticationPlugin.java
index 5fd18a1..320f661 100644
--- a/solr/core/src/java/org/apache/solr/security/AuthenticationPlugin.java
+++ b/solr/core/src/java/org/apache/solr/security/AuthenticationPlugin.java
@@ -19,39 +19,33 @@
 import javax.servlet.FilterChain;
 import javax.servlet.ServletRequest;
 import javax.servlet.ServletResponse;
-import java.io.Closeable;
-import java.util.Arrays;
 import java.util.Map;
 import java.util.Set;
 import java.util.concurrent.ConcurrentHashMap;
 
 import com.codahale.metrics.Counter;
 import com.codahale.metrics.Meter;
-import com.codahale.metrics.MetricRegistry;
 import com.codahale.metrics.Timer;
-import org.apache.solr.core.SolrInfoBean;
-import org.apache.solr.metrics.SolrMetricManager;
-import org.apache.solr.metrics.SolrMetricProducer;
-
 import org.apache.http.HttpRequest;
 import org.apache.http.protocol.HttpContext;
+import org.apache.solr.core.SolrInfoBean;
+import org.apache.solr.metrics.SolrMetricProducer;
+import org.apache.solr.metrics.SolrMetricsContext;
 import org.eclipse.jetty.client.api.Request;
 
 /**
  * 
  * @lucene.experimental
  */
-public abstract class AuthenticationPlugin implements Closeable, SolrInfoBean, SolrMetricProducer {
+public abstract class AuthenticationPlugin implements SolrInfoBean, SolrMetricProducer {
 
   final public static String AUTHENTICATION_PLUGIN_PROP = "authenticationPlugin";
   final public static String HTTP_HEADER_X_SOLR_AUTHDATA = "X-Solr-AuthData";
 
   // Metrics
   private Set<String> metricNames = ConcurrentHashMap.newKeySet();
-  private MetricRegistry registry;
+  protected SolrMetricsContext solrMetricsContext;
 
-  protected String registryName;
-  protected SolrMetricManager metricManager;
   protected Meter numErrors = new Meter();
   protected Counter requests = new Counter();
   protected Timer requestTimes = new Timer();
@@ -66,7 +60,7 @@
    * @param pluginConfig Config parameters, possibly from a ZK source
    */
   public abstract void init(Map<String, Object> pluginConfig);
- 
+
   /**
    * This method attempts to authenticate the request. Upon a successful authentication, this
    * must call the next filter in the filter chain and set the user principal of the request,
@@ -107,10 +101,10 @@
    * delegate to {@link PKIAuthenticationPlugin}. Return true to indicate that your plugin
    * did handle the request, or false to signal that PKI plugin should handle it. This method
    * will be called by {@link PKIAuthenticationPlugin}'s interceptor.
-   * 
+   *
    * <p>
    *   If not overridden, this method will return true for plugins implementing {@link HttpClientBuilderPlugin}.
-   *   This method can be overridden by subclasses e.g. to set HTTP headers, even if you don't use a clientBuilder. 
+   *   This method can be overridden by subclasses e.g. to set HTTP headers, even if you don't use a clientBuilder.
    * </p>
    * @param httpRequest the httpRequest that is about to be sent to another internal Solr node
    * @param httpContext the context of that request.
@@ -137,7 +131,7 @@
   protected boolean interceptInternodeRequest(Request request) {
     return this instanceof HttpClientBuilderPlugin;
   }
-  
+
   /**
    * Cleanup any per request  data
    */
@@ -145,23 +139,24 @@
   }
 
   @Override
-  public void initializeMetrics(SolrMetricManager manager, String registryName, String tag, final String scope) {
-    this.metricManager = manager;
-    this.registryName = registryName;
-    // Metrics
-    registry = manager.registry(registryName);
-    numErrors = manager.meter(this, registryName, "errors", getCategory().toString(), scope);
-    requests = manager.counter(this, registryName, "requests", getCategory().toString(), scope);
-    numAuthenticated = manager.counter(this, registryName, "authenticated", getCategory().toString(), scope);
-    numPassThrough = manager.counter(this, registryName, "passThrough", getCategory().toString(), scope);
-    numWrongCredentials = manager.counter(this, registryName, "failWrongCredentials", getCategory().toString(), scope);
-    numMissingCredentials = manager.counter(this, registryName, "failMissingCredentials", getCategory().toString(), scope);
-    requestTimes = manager.timer(this, registryName, "requestTimes", getCategory().toString(), scope);
-    totalTime = manager.counter(this, registryName, "totalTime", getCategory().toString(), scope);
-    metricNames.addAll(Arrays.asList("errors", "requests", "authenticated", "passThrough",
-        "failWrongCredentials", "failMissingCredentials", "requestTimes", "totalTime"));
+  public SolrMetricsContext getSolrMetricsContext() {
+    return solrMetricsContext;
   }
-  
+
+  @Override
+  public void initializeMetrics(SolrMetricsContext parentContext, String scope) {
+    this.solrMetricsContext = parentContext.getChildContext(this);
+    // Metrics
+    numErrors = this.solrMetricsContext.meter(this, "errors", getCategory().toString(), scope);
+    requests = this.solrMetricsContext.counter(this, "requests", getCategory().toString(), scope);
+    numAuthenticated = this.solrMetricsContext.counter(this, "authenticated",getCategory().toString(), scope);
+    numPassThrough = this.solrMetricsContext.counter(this, "passThrough",  getCategory().toString(), scope);
+    numWrongCredentials = this.solrMetricsContext.counter(this, "failWrongCredentials",getCategory().toString(), scope);
+    numMissingCredentials = this.solrMetricsContext.counter(this,  "failMissingCredentials",getCategory().toString(), scope);
+    requestTimes = this.solrMetricsContext.timer(this,"requestTimes", getCategory().toString(), scope);
+    totalTime = this.solrMetricsContext.counter(this,"totalTime", getCategory().toString(), scope);
+  }
+
   @Override
   public String getName() {
     return this.getClass().getName();
@@ -181,10 +176,4 @@
   public Set<String> getMetricNames() {
     return metricNames;
   }
-
-  @Override
-  public MetricRegistry getMetricRegistry() {
-    return registry;
-  }
-  
 }
diff --git a/solr/core/src/java/org/apache/solr/servlet/SolrDispatchFilter.java b/solr/core/src/java/org/apache/solr/servlet/SolrDispatchFilter.java
index 90d6b17..3c3e26f 100644
--- a/solr/core/src/java/org/apache/solr/servlet/SolrDispatchFilter.java
+++ b/solr/core/src/java/org/apache/solr/servlet/SolrDispatchFilter.java
@@ -77,6 +77,7 @@
 import org.apache.solr.metrics.MetricsMap;
 import org.apache.solr.metrics.OperatingSystemMetricSet;
 import org.apache.solr.metrics.SolrMetricManager;
+import org.apache.solr.metrics.SolrMetricProducer;
 import org.apache.solr.security.AuditEvent;
 import org.apache.solr.security.AuthenticationPlugin;
 import org.apache.solr.security.PKIAuthenticationPlugin;
@@ -108,7 +109,7 @@
   
   private boolean isV2Enabled = !"true".equals(System.getProperty("disable.v2.api", "false"));
 
-  private final String metricTag = Integer.toHexString(hashCode());
+  private final String metricTag = SolrMetricProducer.getUniqueMetricTag(this, null);
   private SolrMetricManager metricManager;
   private String registryName;
   private volatile boolean closeOnDestroy = true;
diff --git a/solr/core/src/java/org/apache/solr/store/blockcache/Metrics.java b/solr/core/src/java/org/apache/solr/store/blockcache/Metrics.java
index 6d9e9ea..d7654b6 100644
--- a/solr/core/src/java/org/apache/solr/store/blockcache/Metrics.java
+++ b/solr/core/src/java/org/apache/solr/store/blockcache/Metrics.java
@@ -20,11 +20,10 @@
 import java.util.concurrent.ConcurrentHashMap;
 import java.util.concurrent.atomic.AtomicLong;
 
-import com.codahale.metrics.MetricRegistry;
 import org.apache.solr.core.SolrInfoBean;
 import org.apache.solr.metrics.MetricsMap;
-import org.apache.solr.metrics.SolrMetricManager;
 import org.apache.solr.metrics.SolrMetricProducer;
+import org.apache.solr.metrics.SolrMetricsContext;
 import org.apache.solr.search.SolrCacheBase;
 
 /**
@@ -54,17 +53,13 @@
   public AtomicLong shardBuffercacheLost = new AtomicLong(0);
 
   private MetricsMap metricsMap;
-  private MetricRegistry registry;
   private Set<String> metricNames = ConcurrentHashMap.newKeySet();
-  private SolrMetricManager metricManager;
-  private String registryName;
+  private SolrMetricsContext solrMetricsContext;
   private long previous = System.nanoTime();
 
   @Override
-  public void initializeMetrics(SolrMetricManager manager, String registryName, String tag, String scope) {
-    this.metricManager = manager;
-    this.registryName = registryName;
-    registry = manager.registry(registryName);
+  public void initializeMetrics(SolrMetricsContext parentContext, String scope) {
+    solrMetricsContext = parentContext.getChildContext(this);
     metricsMap = new MetricsMap((detailed, map) -> {
       long now = System.nanoTime();
       long delta = Math.max(now - previous, 1);
@@ -108,7 +103,7 @@
       previous = now;
 
     });
-    manager.registerGauge(this, registryName, metricsMap, tag, true, getName(), getCategory().toString(), scope);
+    solrMetricsContext.gauge(this, metricsMap, true, getName(), getCategory().toString(), scope);
   }
 
   private float getPerSecond(long value, double seconds) {
@@ -133,8 +128,7 @@
   }
 
   @Override
-  public MetricRegistry getMetricRegistry() {
-    return registry;
+  public SolrMetricsContext getSolrMetricsContext() {
+    return solrMetricsContext;
   }
-
 }
diff --git a/solr/core/src/java/org/apache/solr/store/hdfs/HdfsLocalityReporter.java b/solr/core/src/java/org/apache/solr/store/hdfs/HdfsLocalityReporter.java
index 2bf60cb..0739ede 100644
--- a/solr/core/src/java/org/apache/solr/store/hdfs/HdfsLocalityReporter.java
+++ b/solr/core/src/java/org/apache/solr/store/hdfs/HdfsLocalityReporter.java
@@ -32,8 +32,8 @@
 import org.apache.hadoop.fs.FileSystem;
 import org.apache.solr.core.SolrInfoBean;
 import org.apache.solr.metrics.MetricsMap;
-import org.apache.solr.metrics.SolrMetricManager;
 import org.apache.solr.metrics.SolrMetricProducer;
+import org.apache.solr.metrics.SolrMetricsContext;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
@@ -51,9 +51,7 @@
   private final ConcurrentMap<HdfsDirectory,ConcurrentMap<FileStatus,BlockLocation[]>> cache;
 
   private final Set<String> metricNames = ConcurrentHashMap.newKeySet();
-  private MetricRegistry registry;
-  private SolrMetricManager metricManager;
-  private String registryName;
+  private SolrMetricsContext solrMetricsContext;
 
   public HdfsLocalityReporter() {
     cache = new ConcurrentHashMap<>();
@@ -89,17 +87,20 @@
 
   @Override
   public MetricRegistry getMetricRegistry() {
-    return registry;
+    return solrMetricsContext != null ? solrMetricsContext.getMetricRegistry() : null;
+  }
+
+  @Override
+  public SolrMetricsContext getSolrMetricsContext() {
+    return solrMetricsContext;
   }
 
   /**
    * Provide statistics on HDFS block locality, both in terms of bytes and block counts.
    */
   @Override
-  public void initializeMetrics(SolrMetricManager manager, String registryName, String tag, String scope) {
-    this.metricManager = manager;
-    this.registryName = registryName;
-    registry = manager.registry(registryName);
+  public void initializeMetrics(SolrMetricsContext parentContext, String scope) {
+    solrMetricsContext = parentContext.getChildContext(this);
     MetricsMap metricsMap = new MetricsMap((detailed, map) -> {
       long totalBytes = 0;
       long localBytes = 0;
@@ -149,7 +150,7 @@
         map.put(LOCALITY_BLOCKS_RATIO, localCount / (double) totalCount);
       }
     });
-    manager.registerGauge(this, registryName, metricsMap, tag, true, "hdfsLocality", getCategory().toString(), scope);
+    solrMetricsContext.gauge(this, metricsMap, true, "hdfsLocality", getCategory().toString(), scope);
   }
 
   /**
diff --git a/solr/core/src/java/org/apache/solr/update/DirectUpdateHandler2.java b/solr/core/src/java/org/apache/solr/update/DirectUpdateHandler2.java
index 2b621a8..248f18b 100644
--- a/solr/core/src/java/org/apache/solr/update/DirectUpdateHandler2.java
+++ b/solr/core/src/java/org/apache/solr/update/DirectUpdateHandler2.java
@@ -51,8 +51,8 @@
 import org.apache.solr.common.util.NamedList;
 import org.apache.solr.core.SolrConfig.UpdateHandlerInfo;
 import org.apache.solr.core.SolrCore;
-import org.apache.solr.metrics.SolrMetricManager;
 import org.apache.solr.metrics.SolrMetricProducer;
+import org.apache.solr.metrics.SolrMetricsContext;
 import org.apache.solr.request.LocalSolrQueryRequest;
 import org.apache.solr.request.SolrQueryRequest;
 import org.apache.solr.request.SolrRequestInfo;
@@ -96,8 +96,7 @@
   LongAdder numDocsPending = new LongAdder();
   LongAdder numErrors = new LongAdder();
   Meter numErrorsCumulative;
-  SolrMetricManager metricManager;
-  String registryName;
+  SolrMetricsContext solrMetricsContext;
 
   // tracks when auto-commit should occur
   protected final CommitTracker commitTracker;
@@ -170,48 +169,46 @@
   }
 
   @Override
-  public void initializeMetrics(SolrMetricManager manager, String registryName, String tag, String scope) {
-    this.metricManager = manager;
-    this.registryName = registryName;
-    this.registry = manager.registry(registryName);
-    commitCommands = manager.meter(this, registryName, "commits", getCategory().toString(), scope);
-    manager.registerGauge(this, registryName, () -> commitTracker.getCommitCount(), tag, true, "autoCommits", getCategory().toString(), scope);
-    manager.registerGauge(this, registryName, () -> softCommitTracker.getCommitCount(), tag, true, "softAutoCommits", getCategory().toString(), scope);
+  public void initializeMetrics(SolrMetricsContext parentContext, String scope) {
+    solrMetricsContext = parentContext.getChildContext(this);
+    commitCommands = solrMetricsContext.meter(this, "commits", getCategory().toString(), scope);
+    solrMetricsContext.gauge(this, () -> commitTracker.getCommitCount(), true, "autoCommits", getCategory().toString(), scope);
+    solrMetricsContext.gauge(this, () -> softCommitTracker.getCommitCount(), true, "softAutoCommits", getCategory().toString(), scope);
     if (commitTracker.getDocsUpperBound() > 0) {
-      manager.registerGauge(this, registryName, () -> commitTracker.getDocsUpperBound(), tag, true, "autoCommitMaxDocs",
+      solrMetricsContext.gauge(this, () -> commitTracker.getDocsUpperBound(), true, "autoCommitMaxDocs",
           getCategory().toString(), scope);
     }
     if (commitTracker.getTimeUpperBound() > 0) {
-      manager.registerGauge(this, registryName, () -> "" + commitTracker.getTimeUpperBound() + "ms", tag, true, "autoCommitMaxTime",
+      solrMetricsContext.gauge(this, () -> "" + commitTracker.getTimeUpperBound() + "ms", true, "autoCommitMaxTime",
           getCategory().toString(), scope);
     }
     if (commitTracker.getTLogFileSizeUpperBound() > 0) {
-      manager.registerGauge(this, registryName, () -> commitTracker.getTLogFileSizeUpperBound(), tag, true, "autoCommitMaxSize",
+      solrMetricsContext.gauge(this, () -> commitTracker.getTLogFileSizeUpperBound(), true, "autoCommitMaxSize",
           getCategory().toString(), scope);
     }
     if (softCommitTracker.getDocsUpperBound() > 0) {
-      manager.registerGauge(this, registryName, () -> softCommitTracker.getDocsUpperBound(), tag, true, "softAutoCommitMaxDocs",
+      solrMetricsContext.gauge(this, () -> softCommitTracker.getDocsUpperBound(), true, "softAutoCommitMaxDocs",
           getCategory().toString(), scope);
     }
     if (softCommitTracker.getTimeUpperBound() > 0) {
-      manager.registerGauge(this, registryName, () -> "" + softCommitTracker.getTimeUpperBound() + "ms", tag, true, "softAutoCommitMaxTime",
+      solrMetricsContext.gauge(this, () -> "" + softCommitTracker.getTimeUpperBound() + "ms", true, "softAutoCommitMaxTime",
           getCategory().toString(), scope);
     }
-    optimizeCommands = manager.meter(this, registryName, "optimizes", getCategory().toString(), scope);
-    rollbackCommands = manager.meter(this, registryName, "rollbacks", getCategory().toString(), scope);
-    splitCommands = manager.meter(this, registryName, "splits", getCategory().toString(), scope);
-    mergeIndexesCommands = manager.meter(this, registryName, "merges", getCategory().toString(), scope);
-    expungeDeleteCommands = manager.meter(this, registryName, "expungeDeletes", getCategory().toString(), scope);
-    manager.registerGauge(this, registryName, () -> numDocsPending.longValue(), tag, true, "docsPending", getCategory().toString(), scope);
-    manager.registerGauge(this, registryName, () -> addCommands.longValue(), tag, true, "adds", getCategory().toString(), scope);
-    manager.registerGauge(this, registryName, () -> deleteByIdCommands.longValue(), tag, true, "deletesById", getCategory().toString(), scope);
-    manager.registerGauge(this, registryName, () -> deleteByQueryCommands.longValue(), tag, true, "deletesByQuery", getCategory().toString(), scope);
-    manager.registerGauge(this, registryName, () -> numErrors.longValue(), tag, true, "errors", getCategory().toString(), scope);
+    optimizeCommands = solrMetricsContext.meter(this, "optimizes", getCategory().toString(), scope);
+    rollbackCommands = solrMetricsContext.meter(this, "rollbacks", getCategory().toString(), scope);
+    splitCommands = solrMetricsContext.meter(this, "splits", getCategory().toString(), scope);
+    mergeIndexesCommands = solrMetricsContext.meter(this, "merges", getCategory().toString(), scope);
+    expungeDeleteCommands = solrMetricsContext.meter(this, "expungeDeletes", getCategory().toString(), scope);
+    solrMetricsContext.gauge(this, () -> numDocsPending.longValue(), true, "docsPending", getCategory().toString(), scope);
+    solrMetricsContext.gauge(this, () -> addCommands.longValue(), true, "adds", getCategory().toString(), scope);
+    solrMetricsContext.gauge(this, () -> deleteByIdCommands.longValue(), true, "deletesById", getCategory().toString(), scope);
+    solrMetricsContext.gauge(this, () -> deleteByQueryCommands.longValue(), true, "deletesByQuery", getCategory().toString(), scope);
+    solrMetricsContext.gauge(this, () -> numErrors.longValue(), true, "errors", getCategory().toString(), scope);
 
-    addCommandsCumulative = manager.meter(this, registryName, "cumulativeAdds", getCategory().toString(), scope);
-    deleteByIdCommandsCumulative = manager.meter(this, registryName, "cumulativeDeletesById", getCategory().toString(), scope);
-    deleteByQueryCommandsCumulative = manager.meter(this, registryName, "cumulativeDeletesByQuery", getCategory().toString(), scope);
-    numErrorsCumulative = manager.meter(this, registryName, "cumulativeErrors", getCategory().toString(), scope);
+    addCommandsCumulative = solrMetricsContext.meter(this, "cumulativeAdds", getCategory().toString(), scope);
+    deleteByIdCommandsCumulative = solrMetricsContext.meter(this, "cumulativeDeletesById", getCategory().toString(), scope);
+    deleteByQueryCommandsCumulative = solrMetricsContext.meter(this, "cumulativeDeletesByQuery", getCategory().toString(), scope);
+    numErrorsCumulative = solrMetricsContext.meter(this, "cumulativeErrors", getCategory().toString(), scope);
   }
 
   private void deleteAll() throws IOException {
@@ -805,6 +802,11 @@
     softCommitTracker.close();
 
     numDocsPending.reset();
+    try {
+      SolrMetricProducer.super.close();
+    } catch (Exception e) {
+      throw new IOException("Error closing", e);
+    }
   }
 
 
@@ -915,7 +917,7 @@
   }
 
   /**
-   * Calls either {@link IndexWriter#updateDocValues} or {@link IndexWriter#updateDocument}(s) as
+   * Calls either {@link IndexWriter#updateDocValues} or <code>IndexWriter#updateDocument</code>(s) as
    * needed based on {@link AddUpdateCommand#isInPlaceUpdate}.
    * <p>
    * If the this is an UPDATE_INPLACE cmd, then all fields included in 
diff --git a/solr/core/src/java/org/apache/solr/update/SolrIndexWriter.java b/solr/core/src/java/org/apache/solr/update/SolrIndexWriter.java
index 538a983..55597b1 100644
--- a/solr/core/src/java/org/apache/solr/update/SolrIndexWriter.java
+++ b/solr/core/src/java/org/apache/solr/update/SolrIndexWriter.java
@@ -42,7 +42,7 @@
 import org.apache.solr.core.DirectoryFactory.DirContext;
 import org.apache.solr.core.SolrCore;
 import org.apache.solr.core.SolrInfoBean;
-import org.apache.solr.metrics.SolrMetricManager;
+import org.apache.solr.metrics.SolrMetricsContext;
 import org.apache.solr.schema.IndexSchema;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
@@ -88,8 +88,7 @@
   private final AtomicLong runningMajorMergesDocs = new AtomicLong();
   private final AtomicLong runningMinorMergesDocs = new AtomicLong();
 
-  private final SolrMetricManager metricManager;
-  private final String registryName;
+  private final SolrMetricsContext solrMetricsContext;
   // merge diagnostics.
   private final Map<String, Long> runningMerges = new ConcurrentHashMap<>();
 
@@ -120,8 +119,7 @@
     // no metrics
     mergeTotals = false;
     mergeDetails = false;
-    metricManager = null;
-    registryName = null;
+    solrMetricsContext = null;
   }
 
   private SolrIndexWriter(SolrCore core, String name, String path, Directory directory, boolean create, IndexSchema schema, SolrIndexConfig config, IndexDeletionPolicy delPolicy, Codec codec) throws IOException {
@@ -135,8 +133,7 @@
     infoStream = getConfig().getInfoStream();
     this.directory = directory;
     numOpens.incrementAndGet();
-    metricManager = core.getCoreContainer().getMetricManager();
-    registryName = core.getCoreMetricManager().getRegistryName();
+    solrMetricsContext = core.getSolrMetricsContext().getChildContext(this);
     if (config.metricsInfo != null && config.metricsInfo.initArgs != null) {
       Object v = config.metricsInfo.initArgs.get("majorMergeDocs");
       if (v != null) {
@@ -160,21 +157,21 @@
       }
       if (mergeDetails) {
         mergeTotals = true; // override
-        majorMergedDocs = metricManager.meter(null, registryName, "docs", SolrInfoBean.Category.INDEX.toString(), "merge", "major");
-        majorDeletedDocs = metricManager.meter(null, registryName, "deletedDocs", SolrInfoBean.Category.INDEX.toString(), "merge", "major");
+        majorMergedDocs = solrMetricsContext.meter(null, "docs", SolrInfoBean.Category.INDEX.toString(), "merge", "major");
+        majorDeletedDocs = solrMetricsContext.meter(null, "deletedDocs", SolrInfoBean.Category.INDEX.toString(), "merge", "major");
       }
       if (mergeTotals) {
-        minorMerge = metricManager.timer(null, registryName, "minor", SolrInfoBean.Category.INDEX.toString(), "merge");
-        majorMerge = metricManager.timer(null, registryName, "major", SolrInfoBean.Category.INDEX.toString(), "merge");
-        mergeErrors = metricManager.counter(null, registryName, "errors", SolrInfoBean.Category.INDEX.toString(), "merge");
+        minorMerge = solrMetricsContext.timer(null, "minor", SolrInfoBean.Category.INDEX.toString(), "merge");
+        majorMerge = solrMetricsContext.timer(null, "major", SolrInfoBean.Category.INDEX.toString(), "merge");
+        mergeErrors = solrMetricsContext.counter(null, "errors", SolrInfoBean.Category.INDEX.toString(), "merge");
         String tag = core.getMetricTag();
-        metricManager.registerGauge(null, registryName, () -> runningMajorMerges.get(), tag, true, "running", SolrInfoBean.Category.INDEX.toString(), "merge", "major");
-        metricManager.registerGauge(null, registryName, () -> runningMinorMerges.get(), tag, true, "running", SolrInfoBean.Category.INDEX.toString(), "merge", "minor");
-        metricManager.registerGauge(null, registryName, () -> runningMajorMergesDocs.get(), tag, true, "running.docs", SolrInfoBean.Category.INDEX.toString(), "merge", "major");
-        metricManager.registerGauge(null, registryName, () -> runningMinorMergesDocs.get(), tag, true, "running.docs", SolrInfoBean.Category.INDEX.toString(), "merge", "minor");
-        metricManager.registerGauge(null, registryName, () -> runningMajorMergesSegments.get(), tag, true, "running.segments", SolrInfoBean.Category.INDEX.toString(), "merge", "major");
-        metricManager.registerGauge(null, registryName, () -> runningMinorMergesSegments.get(), tag, true, "running.segments", SolrInfoBean.Category.INDEX.toString(), "merge", "minor");
-        flushMeter = metricManager.meter(null, registryName, "flush", SolrInfoBean.Category.INDEX.toString());
+        solrMetricsContext.gauge(null, () -> runningMajorMerges.get(), true, "running", SolrInfoBean.Category.INDEX.toString(), "merge", "major");
+        solrMetricsContext.gauge(null, () -> runningMinorMerges.get(), true, "running", SolrInfoBean.Category.INDEX.toString(), "merge", "minor");
+        solrMetricsContext.gauge(null, () -> runningMajorMergesDocs.get(), true, "running.docs", SolrInfoBean.Category.INDEX.toString(), "merge", "major");
+        solrMetricsContext.gauge(null, () -> runningMinorMergesDocs.get(), true, "running.docs", SolrInfoBean.Category.INDEX.toString(), "merge", "minor");
+        solrMetricsContext.gauge(null, () -> runningMajorMergesSegments.get(), true, "running.segments", SolrInfoBean.Category.INDEX.toString(), "merge", "major");
+        solrMetricsContext.gauge(null, () -> runningMinorMergesSegments.get(), true, "running.segments", SolrInfoBean.Category.INDEX.toString(), "merge", "minor");
+        flushMeter = solrMetricsContext.meter(null, "flush", SolrInfoBean.Category.INDEX.toString());
       }
     }
   }
@@ -345,6 +342,9 @@
       if (directoryFactory != null) {
         directoryFactory.release(directory);
       }
+      if (solrMetricsContext != null) {
+        solrMetricsContext.unregister();
+      }
     }
   }
 
diff --git a/solr/core/src/java/org/apache/solr/update/UpdateHandler.java b/solr/core/src/java/org/apache/solr/update/UpdateHandler.java
index c8dbc10..59dae8a 100644
--- a/solr/core/src/java/org/apache/solr/update/UpdateHandler.java
+++ b/solr/core/src/java/org/apache/solr/update/UpdateHandler.java
@@ -22,7 +22,6 @@
 import java.util.Vector;
 import java.util.concurrent.ConcurrentHashMap;
 
-import com.codahale.metrics.MetricRegistry;
 import org.apache.solr.core.DirectoryFactory;
 import org.apache.solr.core.HdfsDirectoryFactory;
 import org.apache.solr.core.PluginInfo;
@@ -57,7 +56,6 @@
   protected final UpdateLog ulog;
 
   protected Set<String> metricNames = ConcurrentHashMap.newKeySet();
-  protected MetricRegistry registry;
 
   private void parseEventListeners() {
     final Class<SolrEventListener> clazz = SolrEventListener.class;
@@ -211,8 +209,4 @@
   public Set<String> getMetricNames() {
     return metricNames;
   }
-  @Override
-  public MetricRegistry getMetricRegistry() {
-    return registry;
-  }
 }
diff --git a/solr/core/src/java/org/apache/solr/update/UpdateShardHandler.java b/solr/core/src/java/org/apache/solr/update/UpdateShardHandler.java
index 8e3486b..fe966cb 100644
--- a/solr/core/src/java/org/apache/solr/update/UpdateShardHandler.java
+++ b/solr/core/src/java/org/apache/solr/update/UpdateShardHandler.java
@@ -25,7 +25,6 @@
 import java.util.concurrent.ThreadFactory;
 import java.util.concurrent.TimeUnit;
 
-import com.codahale.metrics.MetricRegistry;
 import com.google.common.annotations.VisibleForTesting;
 import org.apache.http.client.HttpClient;
 import org.apache.http.impl.client.CloseableHttpClient;
@@ -40,6 +39,7 @@
 import org.apache.solr.core.SolrInfoBean;
 import org.apache.solr.metrics.SolrMetricManager;
 import org.apache.solr.metrics.SolrMetricProducer;
+import org.apache.solr.metrics.SolrMetricsContext;
 import org.apache.solr.security.HttpClientBuilderPlugin;
 import org.apache.solr.update.processor.DistributedUpdateProcessor;
 import org.apache.solr.update.processor.DistributingUpdateProcessorFactory;
@@ -90,7 +90,7 @@
 
 
   private final Set<String> metricNames = ConcurrentHashMap.newKeySet();
-  private MetricRegistry registry;
+  private SolrMetricsContext solrMetricsContext;
 
   private int socketTimeout = HttpClientUtil.DEFAULT_SO_TIMEOUT;
   private int connectionTimeout = HttpClientUtil.DEFAULT_CONNECT_TIMEOUT;
@@ -179,14 +179,14 @@
   }
 
   @Override
-  public void initializeMetrics(SolrMetricManager manager, String registryName, String tag, String scope) {
-    registry = manager.registry(registryName);
+  public void initializeMetrics(SolrMetricsContext parentContext, String scope) {
+    solrMetricsContext = parentContext.getChildContext(this);
     String expandedScope = SolrMetricManager.mkName(scope, getCategory().name());
-    updateHttpListenerFactory.initializeMetrics(manager, registryName, tag, expandedScope);
-    defaultConnectionManager.initializeMetrics(manager, registryName, tag, expandedScope);
-    updateExecutor = MetricUtils.instrumentedExecutorService(updateExecutor, this, registry,
+    updateHttpListenerFactory.initializeMetrics(solrMetricsContext, expandedScope);
+    defaultConnectionManager.initializeMetrics(solrMetricsContext, expandedScope);
+    updateExecutor = MetricUtils.instrumentedExecutorService(updateExecutor, this, solrMetricsContext.getMetricRegistry(),
         SolrMetricManager.mkName("updateOnlyExecutor", expandedScope, "threadPool"));
-    recoveryExecutor = MetricUtils.instrumentedExecutorService(recoveryExecutor, this, registry,
+    recoveryExecutor = MetricUtils.instrumentedExecutorService(recoveryExecutor, this, solrMetricsContext.getMetricRegistry(),
         SolrMetricManager.mkName("recoveryExecutor", expandedScope, "threadPool"));
   }
 
@@ -206,8 +206,8 @@
   }
 
   @Override
-  public MetricRegistry getMetricRegistry() {
-    return registry;
+  public SolrMetricsContext getSolrMetricsContext() {
+    return solrMetricsContext;
   }
 
   // if you are looking for a client to use, it's probably this one.
@@ -259,6 +259,11 @@
     } catch (Exception e) {
       throw new RuntimeException(e);
     } finally {
+      try {
+        SolrMetricProducer.super.close();
+      } catch (Exception e) {
+        // do nothing
+      }
       IOUtils.closeQuietly(updateOnlyClient);
       HttpClientUtil.close(recoveryOnlyClient);
       HttpClientUtil.close(defaultClient);
diff --git a/solr/core/src/java/org/apache/solr/util/stats/InstrumentedHttpListenerFactory.java b/solr/core/src/java/org/apache/solr/util/stats/InstrumentedHttpListenerFactory.java
index d452502..c3bc3e5 100644
--- a/solr/core/src/java/org/apache/solr/util/stats/InstrumentedHttpListenerFactory.java
+++ b/solr/core/src/java/org/apache/solr/util/stats/InstrumentedHttpListenerFactory.java
@@ -21,11 +21,10 @@
 import java.util.Locale;
 import java.util.Map;
 
-import com.codahale.metrics.MetricRegistry;
 import com.codahale.metrics.Timer;
 import org.apache.solr.client.solrj.impl.HttpListenerFactory;
-import org.apache.solr.metrics.SolrMetricManager;
 import org.apache.solr.metrics.SolrMetricProducer;
+import org.apache.solr.metrics.SolrMetricsContext;
 import org.eclipse.jetty.client.api.Request;
 import org.eclipse.jetty.client.api.Result;
 
@@ -64,9 +63,7 @@
     KNOWN_METRIC_NAME_STRATEGIES.put("methodOnly", METHOD_ONLY);
   }
 
-  protected MetricRegistry metricsRegistry;
-  protected SolrMetricManager metricManager;
-  protected String registryName;
+  protected SolrMetricsContext solrMetricsContext;
   protected String scope;
   protected NameStrategy nameStrategy;
 
@@ -85,7 +82,7 @@
 
       @Override
       public void onBegin(Request request) {
-        if (metricsRegistry != null) {
+        if (solrMetricsContext != null) {
           timerContext = timer(request).time();
         }
       }
@@ -100,14 +97,12 @@
   }
 
   private Timer timer(Request request) {
-    return metricsRegistry.timer(nameStrategy.getNameFor(scope, request));
+    return solrMetricsContext.timer(null, nameStrategy.getNameFor(scope, request));
   }
 
   @Override
-  public void initializeMetrics(SolrMetricManager manager, String registry, String tag, String scope) {
-    this.metricManager = manager;
-    this.registryName = registry;
-    this.metricsRegistry = manager.registry(registry);
+  public void initializeMetrics(SolrMetricsContext parentContext, String scope) {
+    this.solrMetricsContext = parentContext;
     this.scope = scope;
   }
 }
diff --git a/solr/core/src/java/org/apache/solr/util/stats/InstrumentedPoolingHttpClientConnectionManager.java b/solr/core/src/java/org/apache/solr/util/stats/InstrumentedPoolingHttpClientConnectionManager.java
index 398ab8b..c7397ba 100644
--- a/solr/core/src/java/org/apache/solr/util/stats/InstrumentedPoolingHttpClientConnectionManager.java
+++ b/solr/core/src/java/org/apache/solr/util/stats/InstrumentedPoolingHttpClientConnectionManager.java
@@ -22,6 +22,7 @@
 import org.apache.http.impl.conn.PoolingHttpClientConnectionManager;
 import org.apache.solr.metrics.SolrMetricManager;
 import org.apache.solr.metrics.SolrMetricProducer;
+import org.apache.solr.metrics.SolrMetricsContext;
 
 /**
  * Sub-class of PoolingHttpClientConnectionManager which tracks metrics interesting to Solr.
@@ -29,25 +30,28 @@
  */
 public class InstrumentedPoolingHttpClientConnectionManager extends PoolingHttpClientConnectionManager implements SolrMetricProducer {
 
-  private SolrMetricManager metricManager;
-  private String registryName;
+  private SolrMetricsContext solrMetricsContext;
 
   public InstrumentedPoolingHttpClientConnectionManager(Registry<ConnectionSocketFactory> socketFactoryRegistry) {
     super(socketFactoryRegistry);
   }
 
   @Override
-  public void initializeMetrics(SolrMetricManager manager, String registry, String tag, String scope) {
-    this.metricManager = manager;
-    this.registryName = registry;
-    manager.registerGauge(null, registry, () -> getTotalStats().getAvailable(),
-        tag, true, SolrMetricManager.mkName("availableConnections", scope));
+  public SolrMetricsContext getSolrMetricsContext() {
+    return solrMetricsContext;
+  }
+
+  @Override
+  public void initializeMetrics(SolrMetricsContext parentContext, String scope) {
+    this.solrMetricsContext = parentContext.getChildContext(this);
+    parentContext.gauge(null, () -> getTotalStats().getAvailable(),
+        true, SolrMetricManager.mkName("availableConnections", scope));
     // this acquires a lock on the connection pool; remove if contention sucks
-    manager.registerGauge(null, registry, () -> getTotalStats().getLeased(),
-        tag, true, SolrMetricManager.mkName("leasedConnections", scope));
-    manager.registerGauge(null, registry, () -> getTotalStats().getMax(),
-        tag, true, SolrMetricManager.mkName("maxConnections", scope));
-    manager.registerGauge(null, registry, () -> getTotalStats().getPending(),
-        tag, true, SolrMetricManager.mkName("pendingConnections", scope));
+    parentContext.gauge(null, () -> getTotalStats().getLeased(),
+        true, SolrMetricManager.mkName("leasedConnections", scope));
+    parentContext.gauge(null, () -> getTotalStats().getMax(),
+        true, SolrMetricManager.mkName("maxConnections", scope));
+    parentContext.gauge(null, () -> getTotalStats().getPending(),
+        true, SolrMetricManager.mkName("pendingConnections", scope));
   }
 }
diff --git a/solr/core/src/test/org/apache/solr/cloud/TestLRUStatsCacheCloud.java b/solr/core/src/test/org/apache/solr/cloud/TestLRUStatsCacheCloud.java
index e7ae992..6a51000 100644
--- a/solr/core/src/test/org/apache/solr/cloud/TestLRUStatsCacheCloud.java
+++ b/solr/core/src/test/org/apache/solr/cloud/TestLRUStatsCacheCloud.java
@@ -21,7 +21,8 @@
 /**
  *
  */
-public class TestLRUStatsCacheCloud extends TestBaseStatsCacheCloud {
+public class
+TestLRUStatsCacheCloud extends TestBaseStatsCacheCloud {
   @Override
   protected boolean assertSameScores() {
     return true;
diff --git a/solr/core/src/test/org/apache/solr/handler/admin/MetricsHandlerTest.java b/solr/core/src/test/org/apache/solr/handler/admin/MetricsHandlerTest.java
index a6dbd9e..3b52568 100644
--- a/solr/core/src/test/org/apache/solr/handler/admin/MetricsHandlerTest.java
+++ b/solr/core/src/test/org/apache/solr/handler/admin/MetricsHandlerTest.java
@@ -17,6 +17,7 @@
 
 package org.apache.solr.handler.admin;
 
+import java.util.Arrays;
 import java.util.Map;
 
 import com.codahale.metrics.Counter;
@@ -24,6 +25,15 @@
 import org.apache.solr.common.params.CommonParams;
 import org.apache.solr.common.util.NamedList;
 import org.apache.solr.common.util.SimpleOrderedMap;
+import org.apache.solr.common.util.Utils;
+import org.apache.solr.core.PluginBag;
+import org.apache.solr.core.PluginInfo;
+import org.apache.solr.core.SolrCore;
+import org.apache.solr.handler.RequestHandlerBase;
+import org.apache.solr.metrics.MetricsMap;
+import org.apache.solr.metrics.SolrMetricsContext;
+import org.apache.solr.request.SolrQueryRequest;
+import org.apache.solr.request.SolrRequestHandler;
 import org.apache.solr.response.SolrQueryResponse;
 import org.junit.AfterClass;
 import org.junit.BeforeClass;
@@ -53,12 +63,12 @@
   @AfterClass
   public static void cleanupMetrics() throws Exception {
     if (null != h) {
-      h.getCoreContainer().getMetricManager().registry("solr.jvm"  ).remove("solrtest_foo");
+      h.getCoreContainer().getMetricManager().registry("solr.jvm").remove("solrtest_foo");
       h.getCoreContainer().getMetricManager().registry("solr.jetty").remove("solrtest_foo");
       h.getCoreContainer().getMetricManager().registry("solr.jetty").remove("solrtest_foo:bar");
     }
   }
-  
+
   @Test
   public void test() throws Exception {
     MetricsHandler handler = new MetricsHandler(h.getCoreContainer());
@@ -145,7 +155,7 @@
     assertNotNull(values.get("metrics"));
     values = (NamedList) values.get("metrics");
     assertEquals(1, values.size());
-    assertEquals(13, ((NamedList)values.get("solr.node")).size());
+    assertEquals(13, ((NamedList) values.get("solr.node")).size());
     assertNotNull(values.get("solr.node"));
     values = (NamedList) values.get("solr.node");
     assertNotNull(values.get("CONTAINER.cores.lazy")); // this is a gauge node
@@ -171,7 +181,7 @@
     assertNotNull(values.get("solr.core.collection1"));
     values = (NamedList) values.get("solr.core.collection1");
     assertEquals(1, values.size());
-    Map m = (Map)values.get("CACHE.core.fieldCache");
+    Map m = (Map) values.get("CACHE.core.fieldCache");
     assertNotNull(m);
     assertNotNull(m.get("entries_count"));
 
@@ -223,7 +233,7 @@
     assertTrue(nl.size() > 0);
     nl.forEach((k, v) -> {
       assertTrue(v instanceof Map);
-      Map map = (Map)v;
+      Map map = (Map) v;
       assertTrue(map.size() > 2);
     });
 
@@ -238,7 +248,7 @@
     assertTrue(nl.size() > 0);
     nl.forEach((k, v) -> {
       assertTrue(v instanceof Map);
-      Map map = (Map)v;
+      Map map = (Map) v;
       assertEquals(2, map.size());
       assertNotNull(map.get("inserts"));
       assertNotNull(map.get("size"));
@@ -257,7 +267,7 @@
     Object val = values.findRecursive("metrics", key1);
     assertNotNull(val);
     assertTrue(val instanceof Map);
-    assertTrue(((Map)val).size() >= 2);
+    assertTrue(((Map) val).size() >= 2);
 
     String key2 = "solr.core.collection1:CACHE.core.fieldCache:entries_count";
     resp = new SolrQueryResponse();
@@ -276,7 +286,7 @@
     val = values.findRecursive("metrics", key3);
     assertNotNull(val);
     assertTrue(val instanceof Number);
-    assertEquals(3, ((Number)val).intValue());
+    assertEquals(3, ((Number) val).intValue());
 
     // test multiple keys
     resp = new SolrQueryResponse();
@@ -306,7 +316,7 @@
     handler.handleRequestBody(req(CommonParams.QT, "/admin/metrics", CommonParams.WT, "json",
         MetricsHandler.KEY_PARAM, "foo", MetricsHandler.KEY_PARAM, "foo:bar:baz:xyz"), resp);
     values = resp.getValues();
-    NamedList metrics = (NamedList)values.get("metrics");
+    NamedList metrics = (NamedList) values.get("metrics");
     assertEquals(0, metrics.size());
     assertNotNull(values.findRecursive("errors", "foo"));
     assertNotNull(values.findRecursive("errors", "foo:bar:baz:xyz"));
@@ -316,7 +326,7 @@
     handler.handleRequestBody(req(CommonParams.QT, "/admin/metrics", CommonParams.WT, "json",
         MetricsHandler.KEY_PARAM, "foo:bar:baz"), resp);
     values = resp.getValues();
-    metrics = (NamedList)values.get("metrics");
+    metrics = (NamedList) values.get("metrics");
     assertEquals(0, metrics.size());
     assertNotNull(values.findRecursive("errors", "foo:bar:baz"));
 
@@ -325,8 +335,122 @@
     handler.handleRequestBody(req(CommonParams.QT, "/admin/metrics", CommonParams.WT, "json",
         MetricsHandler.KEY_PARAM, "solr.jetty:unknown:baz"), resp);
     values = resp.getValues();
-    metrics = (NamedList)values.get("metrics");
+    metrics = (NamedList) values.get("metrics");
     assertEquals(0, metrics.size());
     assertNotNull(values.findRecursive("errors", "solr.jetty:unknown:baz"));
   }
+
+  @Test
+  public void testMetricsUnload() throws Exception {
+
+    SolrCore core = h.getCoreContainer().getCore("collection1");//;.getRequestHandlers().put("/dumphandler", new DumpRequestHandler());
+    RefreshablePluginHolder pluginHolder =null;
+    try {
+      PluginInfo info = new PluginInfo(SolrRequestHandler.TYPE, Utils.makeMap("name", "/dumphandler", "class", DumpRequestHandler.class.getName()));
+      DumpRequestHandler requestHandler = new DumpRequestHandler();
+      requestHandler.gaugevals =  Utils.makeMap("d_k1","v1", "d_k2","v2");
+      pluginHolder = new RefreshablePluginHolder(info, requestHandler);
+      core.getRequestHandlers().put("/dumphandler",
+
+          pluginHolder);
+    } finally {
+      core.close();
+    }
+
+
+
+    MetricsHandler handler = new MetricsHandler(h.getCoreContainer());
+
+    SolrQueryResponse resp = new SolrQueryResponse();
+    handler.handleRequestBody(req(CommonParams.QT, "/admin/metrics", CommonParams.WT, "json", MetricsHandler.COMPACT_PARAM, "true", "key", "solr.core.collection1:QUERY./dumphandler.dumphandlergauge"),
+        resp);
+
+    assertEquals("v1", resp.getValues()._getStr(Arrays.asList("metrics", "solr.core.collection1:QUERY./dumphandler.dumphandlergauge","d_k1"), null));
+    assertEquals("v2", resp.getValues()._getStr(Arrays.asList("metrics","solr.core.collection1:QUERY./dumphandler.dumphandlergauge","d_k2"), null));
+    pluginHolder.closeHandler();
+    resp = new SolrQueryResponse();
+    handler.handleRequestBody(req(CommonParams.QT, "/admin/metrics", CommonParams.WT, "json", MetricsHandler.COMPACT_PARAM, "true", "key", "solr.core.collection1:QUERY./dumphandler.dumphandlergauge"),
+        resp);
+
+    assertEquals(null, resp.getValues()._getStr(Arrays.asList("metrics", "solr.core.collection1:QUERY./dumphandler.dumphandlergauge","d_k1"), null));
+    assertEquals(null, resp.getValues()._getStr(Arrays.asList("metrics","solr.core.collection1:QUERY./dumphandler.dumphandlergauge","d_k2"), null));
+
+    DumpRequestHandler requestHandler = new DumpRequestHandler();
+    requestHandler.gaugevals =  Utils.makeMap("d_k1","v1.1", "d_k2","v2.1");
+    pluginHolder.reset(requestHandler);
+    resp = new SolrQueryResponse();
+    handler.handleRequestBody(req(CommonParams.QT, "/admin/metrics", CommonParams.WT, "json", MetricsHandler.COMPACT_PARAM, "true", "key", "solr.core.collection1:QUERY./dumphandler.dumphandlergauge"),
+        resp);
+
+    assertEquals("v1.1", resp.getValues()._getStr(Arrays.asList("metrics", "solr.core.collection1:QUERY./dumphandler.dumphandlergauge","d_k1"), null));
+    assertEquals("v2.1", resp.getValues()._getStr(Arrays.asList("metrics","solr.core.collection1:QUERY./dumphandler.dumphandlergauge","d_k2"), null));
+
+
+  }
+
+  static class RefreshablePluginHolder extends PluginBag.PluginHolder<SolrRequestHandler> {
+
+    private DumpRequestHandler rh;
+    private SolrMetricsContext metricsInfo;
+
+    public RefreshablePluginHolder(PluginInfo info, DumpRequestHandler rh) {
+      super(info);
+      this.rh = rh;
+    }
+
+    @Override
+    public boolean isLoaded() {
+      return true;
+    }
+
+    void closeHandler() throws Exception {
+      this.metricsInfo = rh.getSolrMetricsContext();
+//      if(metricsInfo.tag.contains(String.valueOf(rh.hashCode()))){
+//        //this created a new child metrics
+//        metricsInfo = metricsInfo.getParent();
+//      }
+      this.rh.close();
+    }
+
+    void reset(DumpRequestHandler rh) throws Exception {
+        this.rh = rh;
+        if(metricsInfo != null)
+        this.rh.initializeMetrics(metricsInfo, "/dumphandler");
+    }
+
+
+    @Override
+    public SolrRequestHandler get() {
+      return rh;
+    }
+  }
+
+  public static class DumpRequestHandler extends RequestHandlerBase {
+
+    static String key = DumpRequestHandler.class.getName();
+    Map<String, Object> gaugevals ;
+    @Override
+    public void handleRequestBody(SolrQueryRequest req, SolrQueryResponse rsp) throws Exception {
+      rsp.add("key", key);
+    }
+
+    @Override
+    public String getDescription() {
+      return "DO nothing";
+    }
+
+    @Override
+    public void initializeMetrics(SolrMetricsContext parentContext, String scope) {
+      super.initializeMetrics(parentContext, scope);
+      MetricsMap metrics = new MetricsMap((detailed, map) -> map.putAll(gaugevals));
+      solrMetricsContext.gauge(this,
+           metrics,  true, "dumphandlergauge", getCategory().toString(), scope);
+
+    }
+
+    @Override
+    public Boolean registerV2() {
+      return Boolean.FALSE;
+    }
+  }
 }
diff --git a/solr/core/src/test/org/apache/solr/search/TestCaffeineCache.java b/solr/core/src/test/org/apache/solr/search/TestCaffeineCache.java
index ae7a762..74d4aed 100644
--- a/solr/core/src/test/org/apache/solr/search/TestCaffeineCache.java
+++ b/solr/core/src/test/org/apache/solr/search/TestCaffeineCache.java
@@ -281,5 +281,6 @@
     }
     assertTrue("total ram bytes should be greater than 0", total > 0);
     assertTrue("total ram bytes exceeded limit", total < 1024 * 1024);
+    cache.close();
   }
 }
diff --git a/solr/core/src/test/org/apache/solr/search/TestFastLRUCache.java b/solr/core/src/test/org/apache/solr/search/TestFastLRUCache.java
index 271e9a9..8d3e0eb 100644
--- a/solr/core/src/test/org/apache/solr/search/TestFastLRUCache.java
+++ b/solr/core/src/test/org/apache/solr/search/TestFastLRUCache.java
@@ -30,7 +30,6 @@
 import org.apache.solr.util.ConcurrentLRUCache;
 import org.apache.solr.util.RTimer;
 
-import java.io.IOException;
 import java.util.HashMap;
 import java.util.Map;
 import java.util.Random;
@@ -52,7 +51,7 @@
   String registry = TestUtil.randomSimpleString(random(), 2, 10);
   String scope = TestUtil.randomSimpleString(random(), 2, 10);
 
-  public void testPercentageAutowarm() throws IOException {
+  public void testPercentageAutowarm() throws Exception {
     FastLRUCache<Object, Object> fastCache = new FastLRUCache<>();
     Map<String, String> params = new HashMap<>();
     params.put("size", "100");
@@ -94,7 +93,7 @@
     fastCacheNew.close();
   }
   
-  public void testPercentageAutowarmMultiple() throws IOException {
+  public void testPercentageAutowarmMultiple() throws Exception {
     doTestPercentageAutowarm(100, 50, new int[]{51, 55, 60, 70, 80, 99, 100}, new int[]{1, 2, 3, 5, 10, 20, 30, 40, 50});
     doTestPercentageAutowarm(100, 25, new int[]{76, 80, 99, 100}, new int[]{1, 2, 3, 5, 10, 20, 30, 40, 50, 51, 55, 60, 70});
     doTestPercentageAutowarm(1000, 10, new int[]{901, 930, 950, 999, 1000}, new int[]{1, 5, 100, 200, 300, 400, 800, 899, 900});
@@ -102,7 +101,7 @@
     doTestPercentageAutowarm(100, 0, new int[]{}, new int[]{1, 10, 25, 51, 55, 60, 70, 80, 99, 100, 200, 300});
   }
   
-  private void doTestPercentageAutowarm(int limit, int percentage, int[] hits, int[]misses) {
+  private void doTestPercentageAutowarm(int limit, int percentage, int[] hits, int[]misses) throws Exception {
     FastLRUCache<Object, Object> fastCache = new FastLRUCache<>();
     Map<String, String> params = new HashMap<>();
     params.put("size", String.valueOf(limit));
@@ -136,7 +135,7 @@
     fastCacheNew.close();
   }
   
-  public void testNoAutowarm() throws IOException {
+  public void testNoAutowarm() throws Exception {
     FastLRUCache<Object, Object> fastCache = new FastLRUCache<>();
     Map<String, String> params = new HashMap<>();
     params.put("size", "100");
@@ -166,7 +165,7 @@
     fastCacheNew.close();
   }
   
-  public void testFullAutowarm() throws IOException {
+  public void testFullAutowarm() throws Exception {
     FastLRUCache<Object, Object> cache = new FastLRUCache<>();
     Map<Object, Object> params = new HashMap<>();
     params.put("size", "100");
@@ -196,7 +195,7 @@
     cacheNew.close();
   }
   
-  public void testSimple() throws IOException {
+  public void testSimple() throws Exception {
     FastLRUCache sc = new FastLRUCache();
     Map l = new HashMap();
     l.put("size", "100");
@@ -304,7 +303,7 @@
     System.out.println("time=" + timer.getTime() + ", minSize="+minSize+",maxSize="+maxSize);
   }
 
-  public void testAccountable() {
+  public void testAccountable() throws Exception {
     FastLRUCache<Query, DocSet> sc = new FastLRUCache<>();
     try {
       Map l = new HashMap();
diff --git a/solr/core/src/test/org/apache/solr/search/TestLFUCache.java b/solr/core/src/test/org/apache/solr/search/TestLFUCache.java
index 7989d8e..34a25fa 100644
--- a/solr/core/src/test/org/apache/solr/search/TestLFUCache.java
+++ b/solr/core/src/test/org/apache/solr/search/TestLFUCache.java
@@ -134,7 +134,7 @@
 
 
   @Test
-  public void testSimple() throws IOException {
+  public void testSimple() throws Exception {
     SolrMetricManager metricManager = new SolrMetricManager();
     Random r = random();
     String registry = TestUtil.randomSimpleString(r, 2, 10);
diff --git a/solr/core/src/test/org/apache/solr/search/TestLRUCache.java b/solr/core/src/test/org/apache/solr/search/TestLRUCache.java
index f5b15a0..297dfa2 100644
--- a/solr/core/src/test/org/apache/solr/search/TestLRUCache.java
+++ b/solr/core/src/test/org/apache/solr/search/TestLRUCache.java
@@ -16,7 +16,6 @@
  */
 package org.apache.solr.search;
 
-import java.io.IOException;
 import java.util.HashMap;
 import java.util.Map;
 import java.util.concurrent.TimeUnit;
@@ -38,7 +37,7 @@
   String registry = TestUtil.randomSimpleString(random(), 2, 10);
   String scope = TestUtil.randomSimpleString(random(), 2, 10);
 
-  public void testFullAutowarm() throws IOException {
+  public void testFullAutowarm() throws Exception {
     LRUCache<Object, Object> lruCache = new LRUCache<>();
     Map<String, String> params = new HashMap<>();
     params.put("size", "100");
@@ -64,14 +63,14 @@
     lruCacheNew.close();
   }
   
-  public void testPercentageAutowarm() throws IOException {
+  public void testPercentageAutowarm() throws Exception {
       doTestPercentageAutowarm(100, 50, new int[]{51, 55, 60, 70, 80, 99, 100}, new int[]{1, 2, 3, 5, 10, 20, 30, 40, 50});
       doTestPercentageAutowarm(100, 25, new int[]{76, 80, 99, 100}, new int[]{1, 2, 3, 5, 10, 20, 30, 40, 50, 51, 55, 60, 70});
       doTestPercentageAutowarm(1000, 10, new int[]{901, 930, 950, 999, 1000}, new int[]{1, 5, 100, 200, 300, 400, 800, 899, 900});
       doTestPercentageAutowarm(10, 10, new int[]{10}, new int[]{1, 5, 9, 100, 200, 300, 400, 800, 899, 900});
   }
   
-  private void doTestPercentageAutowarm(int limit, int percentage, int[] hits, int[]misses) {
+  private void doTestPercentageAutowarm(int limit, int percentage, int[] hits, int[]misses) throws Exception {
     LRUCache<Object, Object> lruCache = new LRUCache<>();
     Map<String, String> params = new HashMap<>();
     params.put("size", String.valueOf(limit));
@@ -101,7 +100,7 @@
   }
   
   @SuppressWarnings("unchecked")
-  public void testNoAutowarm() throws IOException {
+  public void testNoAutowarm() throws Exception {
     LRUCache<Object, Object> lruCache = new LRUCache<>();
     lruCache.initializeMetrics(metricManager, registry, "foo", scope);
     Map<String, String> params = new HashMap<>();
diff --git a/solr/solrj/src/java/org/apache/solr/common/util/ExecutorUtil.java b/solr/solrj/src/java/org/apache/solr/common/util/ExecutorUtil.java
index a053a18..e5bad27 100644
--- a/solr/solrj/src/java/org/apache/solr/common/util/ExecutorUtil.java
+++ b/solr/solrj/src/java/org/apache/solr/common/util/ExecutorUtil.java
@@ -72,6 +72,7 @@
   }
 
   public static void shutdownAndAwaitTermination(ExecutorService pool) {
+    if(pool == null) return;
     pool.shutdown(); // Disable new tasks from being submitted
     awaitTermination(pool);
   }