| /* |
| * 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.giraph.worker; |
| |
| import org.apache.giraph.conf.BooleanConfOption; |
| import org.apache.giraph.conf.FloatConfOption; |
| import org.apache.giraph.conf.GiraphConfiguration; |
| import org.apache.giraph.conf.IntConfOption; |
| import org.apache.giraph.utils.MemoryUtils; |
| import org.apache.giraph.utils.ThreadUtils; |
| import org.apache.giraph.zk.ZooKeeperExt; |
| import org.apache.log4j.Logger; |
| import org.apache.zookeeper.CreateMode; |
| import org.apache.zookeeper.KeeperException; |
| import org.apache.zookeeper.ZooDefs; |
| |
| import java.util.concurrent.atomic.AtomicLong; |
| |
| /** |
| * Memory observer to help synchronize when full gcs are happening across all |
| * the workers |
| */ |
| public class MemoryObserver { |
| /** Whether or not to use memory observer */ |
| public static final BooleanConfOption USE_MEMORY_OBSERVER = |
| new BooleanConfOption("giraph.memoryObserver.enabled", false, |
| "Whether or not to use memory observer"); |
| /** For which fraction of free memory will we issue manual gc calls */ |
| public static final FloatConfOption FREE_MEMORY_FRACTION_FOR_GC = |
| new FloatConfOption("giraph.memoryObserver.freeMemoryFractionForGc", 0.1f, |
| "For which fraction of free memory will we issue manual gc calls"); |
| /** Minimum milliseconds between two manual gc calls */ |
| public static final IntConfOption MIN_MS_BETWEEN_FULL_GCS = |
| new IntConfOption("giraph.memoryObserver.minMsBetweenFullGcs", 60 * 1000, |
| "Minimum milliseconds between two manual gc calls"); |
| |
| /** Logger */ |
| private static final Logger LOG = Logger.getLogger(MemoryObserver.class); |
| /** How long does memory observer thread sleep for */ |
| private static final int MEMORY_OBSERVER_SLEEP_MS = 1000; |
| |
| /** When was the last manual gc call */ |
| private final AtomicLong lastManualGc = new AtomicLong(); |
| /** Zookeeper */ |
| private final ZooKeeperExt zk; |
| /** Path on zookeeper for memory observer files */ |
| private final String zkPath; |
| /** Value of conf setting MIN_MS_BETWEEN_FULL_GCS */ |
| private final int minMsBetweenFullGcs; |
| |
| /** |
| * Constructor |
| * |
| * @param zk Zookeeper |
| * @param zkPath Path on zookeeper for memory observer files |
| * @param conf Configration |
| */ |
| public MemoryObserver(final ZooKeeperExt zk, |
| final String zkPath, GiraphConfiguration conf) { |
| this.zk = zk; |
| this.zkPath = zkPath; |
| minMsBetweenFullGcs = MIN_MS_BETWEEN_FULL_GCS.get(conf); |
| |
| if (!USE_MEMORY_OBSERVER.get(conf)) { |
| return; |
| } |
| |
| try { |
| // Create base path for memory observer nodes |
| zk.createOnceExt(zkPath, null, ZooDefs.Ids.OPEN_ACL_UNSAFE, |
| CreateMode.PERSISTENT, true); |
| } catch (KeeperException | InterruptedException e) { |
| LOG.info("Exception occurred", e); |
| } |
| setWatcher(); |
| |
| final float freeMemoryFractionForGc = |
| FREE_MEMORY_FRACTION_FOR_GC.get(conf); |
| ThreadUtils.startThread(new Runnable() { |
| @Override |
| public void run() { |
| |
| while (true) { |
| double freeMemoryFraction = MemoryUtils.freeMemoryFraction(); |
| long msFromLastGc = System.currentTimeMillis() - lastManualGc.get(); |
| if (msFromLastGc > minMsBetweenFullGcs && |
| freeMemoryFraction < freeMemoryFractionForGc) { |
| try { |
| if (LOG.isInfoEnabled()) { |
| LOG.info("Notifying others about low memory (" + |
| freeMemoryFraction + "% free)"); |
| } |
| zk.createExt( |
| zkPath + "/" + System.currentTimeMillis(), |
| new byte[0], |
| ZooDefs.Ids.OPEN_ACL_UNSAFE, |
| CreateMode.EPHEMERAL, |
| false); |
| } catch (KeeperException | InterruptedException e) { |
| LOG.warn("Exception occurred", e); |
| } |
| } |
| if (!ThreadUtils.trySleep(MEMORY_OBSERVER_SLEEP_MS)) { |
| return; |
| } |
| } |
| } |
| }, "memory-observer"); |
| } |
| |
| /** Set watcher on memory observer folder */ |
| private void setWatcher() { |
| try { |
| // Set a watcher on this path |
| zk.getChildrenExt(zkPath, true, false, false); |
| } catch (KeeperException | InterruptedException e) { |
| LOG.warn("Exception occurred", e); |
| } |
| } |
| |
| /** Manually call gc, if enough time from last call has passed */ |
| public void callGc() { |
| long last = lastManualGc.get(); |
| if (System.currentTimeMillis() - last > minMsBetweenFullGcs && |
| lastManualGc.compareAndSet(last, System.currentTimeMillis())) { |
| if (LOG.isInfoEnabled()) { |
| LOG.info("Calling gc manually"); |
| } |
| System.gc(); |
| if (LOG.isInfoEnabled()) { |
| LOG.info("Manual gc call done"); |
| } |
| } |
| setWatcher(); |
| } |
| } |