Author: brandonwilliams Date: Tue Aug 23 20:05:38 2011 New Revision: 1160879
URL: http://svn.apache.org/viewvc?rev=1160879&view=rev Log: work around native memory leak in com.sun.management.GarbageCollectorMXBean patch by brandonwilliams and jbellis for CASSANDRA-2868 Modified: cassandra/branches/cassandra-0.7/CHANGES.txt cassandra/branches/cassandra-0.7/src/java/org/apache/cassandra/service/GCInspector.java Modified: cassandra/branches/cassandra-0.7/CHANGES.txt URL: http://svn.apache.org/viewvc/cassandra/branches/cassandra-0.7/CHANGES.txt?rev=1160879&r1=1160878&r2=1160879&view=diff ============================================================================== --- cassandra/branches/cassandra-0.7/CHANGES.txt (original) +++ cassandra/branches/cassandra-0.7/CHANGES.txt Tue Aug 23 20:05:38 2011 @@ -8,6 +8,8 @@ * avoid retaining references to dropped CFS objects in CompactionManager.estimatedCompactions (CASSANDRA-2708) * remove gossip state when a new IP takes over a token (CASSANDRA-3071) + * work around native memory leak in com.sun.management.GarbageCollectorMXBean + (CASSANDRA-2868) 0.7.8 Modified: cassandra/branches/cassandra-0.7/src/java/org/apache/cassandra/service/GCInspector.java URL: http://svn.apache.org/viewvc/cassandra/branches/cassandra-0.7/src/java/org/apache/cassandra/service/GCInspector.java?rev=1160879&r1=1160878&r2=1160879&view=diff ============================================================================== --- cassandra/branches/cassandra-0.7/src/java/org/apache/cassandra/service/GCInspector.java (original) +++ cassandra/branches/cassandra-0.7/src/java/org/apache/cassandra/service/GCInspector.java Tue Aug 23 20:05:38 2011 @@ -20,11 +20,13 @@ package org.apache.cassandra.service; * */ +import java.lang.management.GarbageCollectorMXBean; import java.lang.management.ManagementFactory; +import java.lang.management.MemoryMXBean; import java.lang.management.MemoryUsage; -import java.lang.reflect.InvocationTargetException; -import java.lang.reflect.Method; -import java.util.*; +import java.util.ArrayList; +import java.util.HashMap; +import java.util.List; import java.util.concurrent.TimeUnit; import javax.management.MBeanServer; import javax.management.ObjectName; @@ -45,32 +47,22 @@ public class GCInspector public static final GCInspector instance = new GCInspector(); private HashMap<String, Long> gctimes = new HashMap<String, Long>(); + private HashMap<String, Long> gccounts = new HashMap<String, Long>(); + + List<GarbageCollectorMXBean> beans = new ArrayList<GarbageCollectorMXBean>(); + MemoryMXBean membean = ManagementFactory.getMemoryMXBean(); - List<Object> beans = new ArrayList<Object>(); // these are instances of com.sun.management.GarbageCollectorMXBean private volatile boolean cacheSizesReduced; public GCInspector() { - // we only want this class to do its thing on sun jdks, or when the sun classes are present. - Class gcBeanClass = null; - try - { - gcBeanClass = Class.forName("com.sun.management.GarbageCollectorMXBean"); - Class.forName("com.sun.management.GcInfo"); - } - catch (ClassNotFoundException ex) - { - // this happens when using a non-sun jdk. - logger.warn("Cannot load sun GC monitoring classes. GCInspector is disabled."); - } - MBeanServer server = ManagementFactory.getPlatformMBeanServer(); try { ObjectName gcName = new ObjectName(ManagementFactory.GARBAGE_COLLECTOR_MXBEAN_DOMAIN_TYPE + ",*"); for (ObjectName name : server.queryNames(gcName, null)) { - Object gc = ManagementFactory.newPlatformMXBeanProxy(server, name.getCanonicalName(), gcBeanClass); + GarbageCollectorMXBean gc = ManagementFactory.newPlatformMXBeanProxy(server, name.getCanonicalName(), GarbageCollectorMXBean.class); beans.add(gc); } } @@ -97,43 +89,42 @@ public class GCInspector private void logGCResults() { - for (Object gc : beans) + for (GarbageCollectorMXBean gc : beans) { - SunGcWrapper gcw = new SunGcWrapper(gc); - if (gcw.isLastGcInfoNull()) + Long previousTotal = gctimes.get(gc.getName()); + Long total = gc.getCollectionTime(); + if (previousTotal == null) + previousTotal = 0L; + if (previousTotal.equals(total)) continue; - - Long previous = gctimes.get(gcw.getName()); - if (previous != null && previous.longValue() == gcw.getCollectionTime().longValue()) - continue; - gctimes.put(gcw.getName(), gcw.getCollectionTime()); - - long previousMemoryUsed = 0; - long memoryUsed = 0; - long memoryMax = 0; - for (Map.Entry<String, MemoryUsage> entry : gcw.getMemoryUsageBeforeGc().entrySet()) - { - previousMemoryUsed += entry.getValue().getUsed(); - } - for (Map.Entry<String, MemoryUsage> entry : gcw.getMemoryUsageAfterGc().entrySet()) - { - MemoryUsage mu = entry.getValue(); - memoryUsed += mu.getUsed(); - memoryMax += mu.getMax(); - } - - String st = String.format("GC for %s: %s ms, %s reclaimed leaving %s used; max is %s", - gcw.getName(), gcw.getDuration(), previousMemoryUsed - memoryUsed, memoryUsed, memoryMax); - if (gcw.getDuration() > MIN_DURATION) + gctimes.put(gc.getName(), total); + Long duration = total - previousTotal; + assert duration > 0; + + Long previousCount = gccounts.get(gc.getName()); + Long count = gc.getCollectionCount(); + if (previousCount == null) + previousCount = 0L; + gccounts.put(gc.getName(), count); + assert count > previousCount; + + MemoryUsage mu = membean.getHeapMemoryUsage(); + long memoryUsed = mu.getUsed(); + long memoryMax = mu.getMax(); + + String st = String.format("GC for %s: %s ms for %s collections, %s used; max is %s", + gc.getName(), duration, count - previousCount, memoryUsed, memoryMax); + long durationPerCollection = duration / (count - previousCount); + if (durationPerCollection > MIN_DURATION) logger.info(st); else if (logger.isDebugEnabled()) logger.debug(st); - if (gcw.getDuration() > MIN_DURATION_TPSTATS) + if (durationPerCollection > MIN_DURATION_TPSTATS) StatusLogger.log(); // if we just finished a full collection and we're still using a lot of memory, try to reduce the pressure - if (gcw.getName().equals("ConcurrentMarkSweep")) + if (gc.getName().equals("ConcurrentMarkSweep")) { double usage = (double) memoryUsed / memoryMax; @@ -152,82 +143,4 @@ public class GCInspector } } } - - // wrapper for sun class. this enables other jdks to compile this class. - private static final class SunGcWrapper - { - - private Map<String, MemoryUsage> usageBeforeGc = null; - private Map<String, MemoryUsage> usageAfterGc = null; - private String name; - private Long collectionTime; - private Long duration; - - SunGcWrapper(Object gcMxBean) - { - // if we've gotten this far, we've already verified that the right classes are in the CP. Now we just - // need to check for boneheadedness. - // grab everything we need here so that we don't have to deal with try/catch everywhere. - try - { - assert Class.forName("com.sun.management.GarbageCollectorMXBean").isAssignableFrom(gcMxBean.getClass()); - Method getGcInfo = gcMxBean.getClass().getDeclaredMethod("getLastGcInfo"); - Object lastGcInfo = getGcInfo.invoke(gcMxBean); - if (lastGcInfo != null) - { - usageBeforeGc = (Map<String, MemoryUsage>)lastGcInfo.getClass().getDeclaredMethod("getMemoryUsageBeforeGc").invoke(lastGcInfo); - usageAfterGc = (Map<String, MemoryUsage>)lastGcInfo.getClass().getDeclaredMethod("getMemoryUsageAfterGc").invoke(lastGcInfo); - duration = (Long)lastGcInfo.getClass().getDeclaredMethod("getDuration").invoke(lastGcInfo); - name = (String)gcMxBean.getClass().getDeclaredMethod("getName").invoke(gcMxBean); - collectionTime = (Long)gcMxBean.getClass().getDeclaredMethod("getCollectionTime").invoke(gcMxBean); - } - } - catch (ClassNotFoundException e) - { - throw new RuntimeException(e); - } - catch (NoSuchMethodException e) - { - throw new RuntimeException(e); - } - catch (IllegalAccessException e) - { - throw new RuntimeException(e); - } - catch (InvocationTargetException e) - { - throw new RuntimeException(e); - } - } - - String getName() - { - return name; - } - - Long getCollectionTime() - { - return collectionTime; - } - - Long getDuration() - { - return duration; - } - - Map<String, MemoryUsage> getMemoryUsageAfterGc() - { - return usageAfterGc; - } - - Map<String, MemoryUsage> getMemoryUsageBeforeGc() - { - return usageBeforeGc; - } - - boolean isLastGcInfoNull() - { - return usageBeforeGc == null; - } - } }
