Author: gdusbabek
Date: Fri Jul 30 13:46:50 2010
New Revision: 980790
URL: http://svn.apache.org/viewvc?rev=980790&view=rev
Log:
use reflection to avoid compile dependency on sun classes. do not start thread
when sun classes are not present at runtime. patch by gdusbabek, reviewed by
brandonwilliams. CASSANDRA-1061
Modified:
cassandra/branches/cassandra-0.6/src/java/org/apache/cassandra/service/GCInspector.java
Modified:
cassandra/branches/cassandra-0.6/src/java/org/apache/cassandra/service/GCInspector.java
URL:
http://svn.apache.org/viewvc/cassandra/branches/cassandra-0.6/src/java/org/apache/cassandra/service/GCInspector.java?rev=980790&r1=980789&r2=980790&view=diff
==============================================================================
---
cassandra/branches/cassandra-0.6/src/java/org/apache/cassandra/service/GCInspector.java
(original)
+++
cassandra/branches/cassandra-0.6/src/java/org/apache/cassandra/service/GCInspector.java
Fri Jul 30 13:46:50 2010
@@ -23,15 +23,12 @@ package org.apache.cassandra.service;
import org.apache.log4j.Logger;
+import java.lang.reflect.InvocationTargetException;
+import java.lang.reflect.Method;
import java.util.*;
-import java.util.concurrent.ExecutorService;
-import org.apache.cassandra.concurrent.JMXEnabledThreadPoolExecutor;
-import org.apache.cassandra.utils.WrappedRunnable;
import org.apache.cassandra.concurrent.IExecutorMBean;
import org.apache.cassandra.db.CompactionManagerMBean;
-import com.sun.management.GarbageCollectorMXBean;
-import com.sun.management.GcInfo;
import java.lang.management.MemoryUsage;
import java.lang.management.ManagementFactory;
import javax.management.JMX;
@@ -51,17 +48,30 @@ public class GCInspector
private HashMap<String, Long> gctimes = new HashMap<String, Long>();
private final MBeanServer server =
ManagementFactory.getPlatformMBeanServer();
- List<GarbageCollectorMXBean> beans = new
ArrayList<GarbageCollectorMXBean>();
+ List<Object> beans = new ArrayList<Object>(); // these are instances of
com.sun.management.GarbageCollectorMXBean
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))
{
- GarbageCollectorMXBean gc =
ManagementFactory.newPlatformMXBeanProxy(server, name.getCanonicalName(),
GarbageCollectorMXBean.class);
+ Object gc = ManagementFactory.newPlatformMXBeanProxy(server,
name.getCanonicalName(), gcBeanClass);
beans.add(gc);
}
}
@@ -73,6 +83,9 @@ public class GCInspector
public void start()
{
+ // don't bother starting a thread that will do nothing.
+ if (beans.size() == 0)
+ return;
TimerTask t = new TimerTask()
{
public void run()
@@ -85,25 +98,25 @@ public class GCInspector
private void logIntervalGCStats()
{
- for (GarbageCollectorMXBean gc : beans)
+ for (Object gc : beans)
{
- GcInfo gci = gc.getLastGcInfo();
- if (gci == null)
+ SunGcWrapper gcw = new SunGcWrapper(gc);
+ if (gcw.isLastGcInfoNull())
continue;
- Long previous = gctimes.get(gc.getName());
- if (previous != null && previous == gc.getCollectionTime())
+ Long previous = gctimes.get(gcw.getName());
+ if (previous != null && previous.longValue() ==
gcw.getCollectionTime().longValue())
continue;
- gctimes.put(gc.getName(), gc.getCollectionTime());
+ gctimes.put(gcw.getName(), gcw.getCollectionTime());
long previousMemoryUsed = 0;
long memoryUsed = 0;
long memoryMax = 0;
- for (Map.Entry<String, MemoryUsage> entry :
gci.getMemoryUsageBeforeGc().entrySet())
+ for (Map.Entry<String, MemoryUsage> entry :
gcw.getMemoryUsageBeforeGc().entrySet())
{
previousMemoryUsed += entry.getValue().getUsed();
}
- for (Map.Entry<String, MemoryUsage> entry :
gci.getMemoryUsageAfterGc().entrySet())
+ for (Map.Entry<String, MemoryUsage> entry :
gcw.getMemoryUsageAfterGc().entrySet())
{
MemoryUsage mu = entry.getValue();
memoryUsed += mu.getUsed();
@@ -111,12 +124,12 @@ public class GCInspector
}
String st = String.format("GC for %s: %s ms, %s reclaimed leaving
%s used; max is %s",
- gc.getName(), gci.getDuration(),
previousMemoryUsed - memoryUsed, memoryUsed, memoryMax);
- if (gci.getDuration() > MIN_DURATION)
+ gcw.getName(), gcw.getDuration(), previousMemoryUsed -
memoryUsed, memoryUsed, memoryMax);
+ if (gcw.getDuration() > MIN_DURATION)
logger.info(st);
else if (logger.isDebugEnabled())
logger.debug(st);
- if (gci.getDuration() > MIN_DURATION_TPSTATS)
+ if (gcw.getDuration() > MIN_DURATION_TPSTATS)
{
try
{
@@ -147,4 +160,84 @@ public class GCInspector
CompactionManagerMBean cmProxy = JMX.newMBeanProxy(server, cm,
CompactionManagerMBean.class);
logger.info(String.format("%-25s%10s%10s", "CompactionManager", "n/a",
cmProxy.getPendingTasks()));
}
+
+
+ // wrapper for sun class. this enables other jdks to compile this class.
+ private 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;
+ }
+ }
+
}
