| <!DOCTYPE HTML> |
| <html lang="en"> |
| <head> |
| <!-- Generated by javadoc (17) --> |
| <title>Source code</title> |
| <meta name="viewport" content="width=device-width, initial-scale=1"> |
| <meta name="description" content="source: package: org.apache.hadoop.hbase.monitoring, class: ThreadLocalServerSideScanMetrics"> |
| <meta name="generator" content="javadoc/SourceToHTMLConverter"> |
| <link rel="stylesheet" type="text/css" href="../../../../../../stylesheet.css" title="Style"> |
| </head> |
| <body class="source-page"> |
| <main role="main"> |
| <div class="source-container"> |
| <pre><span class="source-line-no">001</span><span id="line-1">/*</span> |
| <span class="source-line-no">002</span><span id="line-2"> * Licensed to the Apache Software Foundation (ASF) under one</span> |
| <span class="source-line-no">003</span><span id="line-3"> * or more contributor license agreements. See the NOTICE file</span> |
| <span class="source-line-no">004</span><span id="line-4"> * distributed with this work for additional information</span> |
| <span class="source-line-no">005</span><span id="line-5"> * regarding copyright ownership. The ASF licenses this file</span> |
| <span class="source-line-no">006</span><span id="line-6"> * to you under the Apache License, Version 2.0 (the</span> |
| <span class="source-line-no">007</span><span id="line-7"> * "License"); you may not use this file except in compliance</span> |
| <span class="source-line-no">008</span><span id="line-8"> * with the License. You may obtain a copy of the License at</span> |
| <span class="source-line-no">009</span><span id="line-9"> *</span> |
| <span class="source-line-no">010</span><span id="line-10"> * http://www.apache.org/licenses/LICENSE-2.0</span> |
| <span class="source-line-no">011</span><span id="line-11"> *</span> |
| <span class="source-line-no">012</span><span id="line-12"> * Unless required by applicable law or agreed to in writing, software</span> |
| <span class="source-line-no">013</span><span id="line-13"> * distributed under the License is distributed on an "AS IS" BASIS,</span> |
| <span class="source-line-no">014</span><span id="line-14"> * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.</span> |
| <span class="source-line-no">015</span><span id="line-15"> * See the License for the specific language governing permissions and</span> |
| <span class="source-line-no">016</span><span id="line-16"> * limitations under the License.</span> |
| <span class="source-line-no">017</span><span id="line-17"> */</span> |
| <span class="source-line-no">018</span><span id="line-18">package org.apache.hadoop.hbase.monitoring;</span> |
| <span class="source-line-no">019</span><span id="line-19"></span> |
| <span class="source-line-no">020</span><span id="line-20">import java.util.concurrent.atomic.AtomicLong;</span> |
| <span class="source-line-no">021</span><span id="line-21">import org.apache.hadoop.hbase.client.metrics.ServerSideScanMetrics;</span> |
| <span class="source-line-no">022</span><span id="line-22">import org.apache.hadoop.hbase.regionserver.RegionScanner;</span> |
| <span class="source-line-no">023</span><span id="line-23">import org.apache.hadoop.hbase.regionserver.ScannerContext;</span> |
| <span class="source-line-no">024</span><span id="line-24">import org.apache.yetus.audience.InterfaceAudience;</span> |
| <span class="source-line-no">025</span><span id="line-25"></span> |
| <span class="source-line-no">026</span><span id="line-26">/**</span> |
| <span class="source-line-no">027</span><span id="line-27"> * Thread-local storage for server-side scan metrics that captures performance data separately for</span> |
| <span class="source-line-no">028</span><span id="line-28"> * each scan thread. This class works in conjunction with {@link ServerSideScanMetrics} to provide</span> |
| <span class="source-line-no">029</span><span id="line-29"> * comprehensive scan performance monitoring.</span> |
| <span class="source-line-no">030</span><span id="line-30"> * <h3>Purpose and Design</h3> {@link ServerSideScanMetrics} captures scan metrics on the server</span> |
| <span class="source-line-no">031</span><span id="line-31"> * side and passes them back to the client in protocol buffer responses. However, the</span> |
| <span class="source-line-no">032</span><span id="line-32"> * {@link ServerSideScanMetrics} instance is not readily available at deeper layers in HBase where</span> |
| <span class="source-line-no">033</span><span id="line-33"> * HFiles are read and individual HFile blocks are accessed. To avoid the complexity of passing</span> |
| <span class="source-line-no">034</span><span id="line-34"> * {@link ServerSideScanMetrics} instances through method calls across multiple layers, this class</span> |
| <span class="source-line-no">035</span><span id="line-35"> * provides thread-local storage for metrics collection.</span> |
| <span class="source-line-no">036</span><span id="line-36"> * <h3>Thread Safety and HBase Architecture</h3> This class leverages a critical aspect of HBase</span> |
| <span class="source-line-no">037</span><span id="line-37"> * server design: on the server side, the thread that opens a {@link RegionScanner} and calls</span> |
| <span class="source-line-no">038</span><span id="line-38"> * {@link RegionScanner#nextRaw(java.util.List, ScannerContext)} is the same thread that reads HFile</span> |
| <span class="source-line-no">039</span><span id="line-39"> * blocks. This design allows thread-local storage to effectively capture metrics without</span> |
| <span class="source-line-no">040</span><span id="line-40"> * cross-thread synchronization.</span> |
| <span class="source-line-no">041</span><span id="line-41"> * <h3>Special Handling for Parallel Operations</h3> The only deviation from the single-thread model</span> |
| <span class="source-line-no">042</span><span id="line-42"> * occurs when {@link org.apache.hadoop.hbase.regionserver.handler.ParallelSeekHandler} is used for</span> |
| <span class="source-line-no">043</span><span id="line-43"> * parallel store file seeking. In this case, special handling ensures that metrics are captured</span> |
| <span class="source-line-no">044</span><span id="line-44"> * correctly across multiple threads. The</span> |
| <span class="source-line-no">045</span><span id="line-45"> * {@link org.apache.hadoop.hbase.regionserver.handler.ParallelSeekHandler} captures metrics from</span> |
| <span class="source-line-no">046</span><span id="line-46"> * worker threads and aggregates them back to the main scan thread. Please refer to the javadoc of</span> |
| <span class="source-line-no">047</span><span id="line-47"> * {@link org.apache.hadoop.hbase.regionserver.handler.ParallelSeekHandler} for detailed information</span> |
| <span class="source-line-no">048</span><span id="line-48"> * about this parallel processing mechanism.</span> |
| <span class="source-line-no">049</span><span id="line-49"> * <h3>Usage Pattern</h3></span> |
| <span class="source-line-no">050</span><span id="line-50"> * <ol></span> |
| <span class="source-line-no">051</span><span id="line-51"> * <li>Enable metrics collection: {@link #setScanMetricsEnabled(boolean)}</li></span> |
| <span class="source-line-no">052</span><span id="line-52"> * <li>Reset counters at scan start: {@link #reset()}</li></span> |
| <span class="source-line-no">053</span><span id="line-53"> * <li>Increment counters during I/O operations using the various {@code add*} methods</li></span> |
| <span class="source-line-no">054</span><span id="line-54"> * <li>Populate the main metrics object:</span> |
| <span class="source-line-no">055</span><span id="line-55"> * {@link #populateServerSideScanMetrics(ServerSideScanMetrics)}</li></span> |
| <span class="source-line-no">056</span><span id="line-56"> * </ol></span> |
| <span class="source-line-no">057</span><span id="line-57"> * <h3>Thread Safety</h3> This class is thread-safe. Each thread maintains its own set of counters</span> |
| <span class="source-line-no">058</span><span id="line-58"> * through {@link ThreadLocal} storage, ensuring that metrics from different scan operations do not</span> |
| <span class="source-line-no">059</span><span id="line-59"> * interfere with each other.</span> |
| <span class="source-line-no">060</span><span id="line-60"> * @see ServerSideScanMetrics</span> |
| <span class="source-line-no">061</span><span id="line-61"> * @see RegionScanner</span> |
| <span class="source-line-no">062</span><span id="line-62"> * @see org.apache.hadoop.hbase.regionserver.handler.ParallelSeekHandler</span> |
| <span class="source-line-no">063</span><span id="line-63"> */</span> |
| <span class="source-line-no">064</span><span id="line-64">@InterfaceAudience.Private</span> |
| <span class="source-line-no">065</span><span id="line-65">public final class ThreadLocalServerSideScanMetrics {</span> |
| <span class="source-line-no">066</span><span id="line-66"> private ThreadLocalServerSideScanMetrics() {</span> |
| <span class="source-line-no">067</span><span id="line-67"> }</span> |
| <span class="source-line-no">068</span><span id="line-68"></span> |
| <span class="source-line-no">069</span><span id="line-69"> private static final ThreadLocal<Boolean> IS_SCAN_METRICS_ENABLED =</span> |
| <span class="source-line-no">070</span><span id="line-70"> ThreadLocal.withInitial(() -> false);</span> |
| <span class="source-line-no">071</span><span id="line-71"></span> |
| <span class="source-line-no">072</span><span id="line-72"> private static final ThreadLocal<AtomicLong> BYTES_READ_FROM_FS =</span> |
| <span class="source-line-no">073</span><span id="line-73"> ThreadLocal.withInitial(() -> new AtomicLong(0));</span> |
| <span class="source-line-no">074</span><span id="line-74"></span> |
| <span class="source-line-no">075</span><span id="line-75"> private static final ThreadLocal<AtomicLong> BYTES_READ_FROM_BLOCK_CACHE =</span> |
| <span class="source-line-no">076</span><span id="line-76"> ThreadLocal.withInitial(() -> new AtomicLong(0));</span> |
| <span class="source-line-no">077</span><span id="line-77"></span> |
| <span class="source-line-no">078</span><span id="line-78"> private static final ThreadLocal<AtomicLong> BYTES_READ_FROM_MEMSTORE =</span> |
| <span class="source-line-no">079</span><span id="line-79"> ThreadLocal.withInitial(() -> new AtomicLong(0));</span> |
| <span class="source-line-no">080</span><span id="line-80"></span> |
| <span class="source-line-no">081</span><span id="line-81"> private static final ThreadLocal<AtomicLong> BLOCK_READ_OPS_COUNT =</span> |
| <span class="source-line-no">082</span><span id="line-82"> ThreadLocal.withInitial(() -> new AtomicLong(0));</span> |
| <span class="source-line-no">083</span><span id="line-83"></span> |
| <span class="source-line-no">084</span><span id="line-84"> public static void setScanMetricsEnabled(boolean enable) {</span> |
| <span class="source-line-no">085</span><span id="line-85"> IS_SCAN_METRICS_ENABLED.set(enable);</span> |
| <span class="source-line-no">086</span><span id="line-86"> }</span> |
| <span class="source-line-no">087</span><span id="line-87"></span> |
| <span class="source-line-no">088</span><span id="line-88"> public static long addBytesReadFromFs(long bytes) {</span> |
| <span class="source-line-no">089</span><span id="line-89"> return BYTES_READ_FROM_FS.get().addAndGet(bytes);</span> |
| <span class="source-line-no">090</span><span id="line-90"> }</span> |
| <span class="source-line-no">091</span><span id="line-91"></span> |
| <span class="source-line-no">092</span><span id="line-92"> public static long addBytesReadFromBlockCache(long bytes) {</span> |
| <span class="source-line-no">093</span><span id="line-93"> return BYTES_READ_FROM_BLOCK_CACHE.get().addAndGet(bytes);</span> |
| <span class="source-line-no">094</span><span id="line-94"> }</span> |
| <span class="source-line-no">095</span><span id="line-95"></span> |
| <span class="source-line-no">096</span><span id="line-96"> public static long addBytesReadFromMemstore(long bytes) {</span> |
| <span class="source-line-no">097</span><span id="line-97"> return BYTES_READ_FROM_MEMSTORE.get().addAndGet(bytes);</span> |
| <span class="source-line-no">098</span><span id="line-98"> }</span> |
| <span class="source-line-no">099</span><span id="line-99"></span> |
| <span class="source-line-no">100</span><span id="line-100"> public static long addBlockReadOpsCount(long count) {</span> |
| <span class="source-line-no">101</span><span id="line-101"> return BLOCK_READ_OPS_COUNT.get().addAndGet(count);</span> |
| <span class="source-line-no">102</span><span id="line-102"> }</span> |
| <span class="source-line-no">103</span><span id="line-103"></span> |
| <span class="source-line-no">104</span><span id="line-104"> public static boolean isScanMetricsEnabled() {</span> |
| <span class="source-line-no">105</span><span id="line-105"> return IS_SCAN_METRICS_ENABLED.get();</span> |
| <span class="source-line-no">106</span><span id="line-106"> }</span> |
| <span class="source-line-no">107</span><span id="line-107"></span> |
| <span class="source-line-no">108</span><span id="line-108"> public static AtomicLong getBytesReadFromFsCounter() {</span> |
| <span class="source-line-no">109</span><span id="line-109"> return BYTES_READ_FROM_FS.get();</span> |
| <span class="source-line-no">110</span><span id="line-110"> }</span> |
| <span class="source-line-no">111</span><span id="line-111"></span> |
| <span class="source-line-no">112</span><span id="line-112"> public static AtomicLong getBytesReadFromBlockCacheCounter() {</span> |
| <span class="source-line-no">113</span><span id="line-113"> return BYTES_READ_FROM_BLOCK_CACHE.get();</span> |
| <span class="source-line-no">114</span><span id="line-114"> }</span> |
| <span class="source-line-no">115</span><span id="line-115"></span> |
| <span class="source-line-no">116</span><span id="line-116"> public static AtomicLong getBytesReadFromMemstoreCounter() {</span> |
| <span class="source-line-no">117</span><span id="line-117"> return BYTES_READ_FROM_MEMSTORE.get();</span> |
| <span class="source-line-no">118</span><span id="line-118"> }</span> |
| <span class="source-line-no">119</span><span id="line-119"></span> |
| <span class="source-line-no">120</span><span id="line-120"> public static AtomicLong getBlockReadOpsCountCounter() {</span> |
| <span class="source-line-no">121</span><span id="line-121"> return BLOCK_READ_OPS_COUNT.get();</span> |
| <span class="source-line-no">122</span><span id="line-122"> }</span> |
| <span class="source-line-no">123</span><span id="line-123"></span> |
| <span class="source-line-no">124</span><span id="line-124"> public static long getBytesReadFromFsAndReset() {</span> |
| <span class="source-line-no">125</span><span id="line-125"> return getBytesReadFromFsCounter().getAndSet(0);</span> |
| <span class="source-line-no">126</span><span id="line-126"> }</span> |
| <span class="source-line-no">127</span><span id="line-127"></span> |
| <span class="source-line-no">128</span><span id="line-128"> public static long getBytesReadFromBlockCacheAndReset() {</span> |
| <span class="source-line-no">129</span><span id="line-129"> return getBytesReadFromBlockCacheCounter().getAndSet(0);</span> |
| <span class="source-line-no">130</span><span id="line-130"> }</span> |
| <span class="source-line-no">131</span><span id="line-131"></span> |
| <span class="source-line-no">132</span><span id="line-132"> public static long getBytesReadFromMemstoreAndReset() {</span> |
| <span class="source-line-no">133</span><span id="line-133"> return getBytesReadFromMemstoreCounter().getAndSet(0);</span> |
| <span class="source-line-no">134</span><span id="line-134"> }</span> |
| <span class="source-line-no">135</span><span id="line-135"></span> |
| <span class="source-line-no">136</span><span id="line-136"> public static long getBlockReadOpsCountAndReset() {</span> |
| <span class="source-line-no">137</span><span id="line-137"> return getBlockReadOpsCountCounter().getAndSet(0);</span> |
| <span class="source-line-no">138</span><span id="line-138"> }</span> |
| <span class="source-line-no">139</span><span id="line-139"></span> |
| <span class="source-line-no">140</span><span id="line-140"> public static void reset() {</span> |
| <span class="source-line-no">141</span><span id="line-141"> getBytesReadFromFsAndReset();</span> |
| <span class="source-line-no">142</span><span id="line-142"> getBytesReadFromBlockCacheAndReset();</span> |
| <span class="source-line-no">143</span><span id="line-143"> getBytesReadFromMemstoreAndReset();</span> |
| <span class="source-line-no">144</span><span id="line-144"> getBlockReadOpsCountAndReset();</span> |
| <span class="source-line-no">145</span><span id="line-145"> }</span> |
| <span class="source-line-no">146</span><span id="line-146"></span> |
| <span class="source-line-no">147</span><span id="line-147"> public static void populateServerSideScanMetrics(ServerSideScanMetrics metrics) {</span> |
| <span class="source-line-no">148</span><span id="line-148"> if (metrics == null) {</span> |
| <span class="source-line-no">149</span><span id="line-149"> return;</span> |
| <span class="source-line-no">150</span><span id="line-150"> }</span> |
| <span class="source-line-no">151</span><span id="line-151"> metrics.addToCounter(ServerSideScanMetrics.BYTES_READ_FROM_FS_METRIC_NAME,</span> |
| <span class="source-line-no">152</span><span id="line-152"> getBytesReadFromFsCounter().get());</span> |
| <span class="source-line-no">153</span><span id="line-153"> metrics.addToCounter(ServerSideScanMetrics.BYTES_READ_FROM_BLOCK_CACHE_METRIC_NAME,</span> |
| <span class="source-line-no">154</span><span id="line-154"> getBytesReadFromBlockCacheCounter().get());</span> |
| <span class="source-line-no">155</span><span id="line-155"> metrics.addToCounter(ServerSideScanMetrics.BYTES_READ_FROM_MEMSTORE_METRIC_NAME,</span> |
| <span class="source-line-no">156</span><span id="line-156"> getBytesReadFromMemstoreCounter().get());</span> |
| <span class="source-line-no">157</span><span id="line-157"> metrics.addToCounter(ServerSideScanMetrics.BLOCK_READ_OPS_COUNT_METRIC_NAME,</span> |
| <span class="source-line-no">158</span><span id="line-158"> getBlockReadOpsCountCounter().get());</span> |
| <span class="source-line-no">159</span><span id="line-159"> }</span> |
| <span class="source-line-no">160</span><span id="line-160">}</span> |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| </pre> |
| </div> |
| </main> |
| </body> |
| </html> |
