/*
* 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.cassandra.service;
import java.lang.management.ManagementFactory;
import java.lang.management.MemoryUsage;
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.atomic.AtomicReference;
import javax.management.MBeanServer;
import javax.management.Notification;
import javax.management.NotificationListener;
import javax.management.ObjectName;
import javax.management.openmbean.CompositeData;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import com.sun.management.GarbageCollectionNotificationInfo;
import org.apache.cassandra.io.sstable.SSTableDeletingTask;
import org.apache.cassandra.utils.StatusLogger;
public class GCInspector implements NotificationListener, GCInspectorMXBean
{
public static final String MBEAN_NAME = "org.apache.cassandra.service:type=GCInspector";
private static final Logger logger = LoggerFactory.getLogger(GCInspector.class);
final static long MIN_LOG_DURATION = 200;
final static long MIN_LOG_DURATION_TPSTATS = 1000;
static final class State
{
final double maxRealTimeElapsed;
final double totalRealTimeElapsed;
final double sumSquaresRealTimeElapsed;
final double totalBytesReclaimed;
final double count;
final long startNanos;
State(double extraElapsed, double extraBytes, State prev)
{
this.totalRealTimeElapsed = prev.totalRealTimeElapsed + extraElapsed;
this.totalBytesReclaimed = prev.totalBytesReclaimed + extraBytes;
this.sumSquaresRealTimeElapsed = prev.sumSquaresRealTimeElapsed + (extraElapsed * extraElapsed);
this.startNanos = prev.startNanos;
this.count = prev.count + 1;
this.maxRealTimeElapsed = Math.max(prev.maxRealTimeElapsed, extraElapsed);
}
State()
{
count = maxRealTimeElapsed = sumSquaresRealTimeElapsed = totalRealTimeElapsed = totalBytesReclaimed = 0;
startNanos = System.nanoTime();
}
}
final AtomicReference<State> state = new AtomicReference<>(new State());
public GCInspector()
{
MBeanServer mbs = ManagementFactory.getPlatformMBeanServer();
try
{
mbs.registerMBean(this, new ObjectName(MBEAN_NAME));
}
catch (Exception e)
{
throw new RuntimeException(e);
}
}
public static void register() throws Exception
{
GCInspector inspector = new GCInspector();
MBeanServer server = ManagementFactory.getPlatformMBeanServer();
ObjectName gcName = new ObjectName(ManagementFactory.GARBAGE_COLLECTOR_MXBEAN_DOMAIN_TYPE + ",*");
for (ObjectName name : server.queryNames(gcName, null))
{
server.addNotificationListener(name, inspector, null, null);
}
}
public void handleNotification(Notification notification, Object handback)
{
String type = notification.getType();
if (type.equals(GarbageCollectionNotificationInfo.GARBAGE_COLLECTION_NOTIFICATION))
{
// retrieve the garbage collection notification information
CompositeData cd = (CompositeData) notification.getUserData();
GarbageCollectionNotificationInfo info = GarbageCollectionNotificationInfo.from(cd);
long duration = info.getGcInfo().getDuration();
StringBuilder sb = new StringBuilder();
sb.append(info.getGcName()).append(" GC in ").append(duration).append("ms. ");
long bytes = 0;
List<String> keys = new ArrayList<>(info.getGcInfo().getMemoryUsageBeforeGc().keySet());
Collections.sort(keys);
for (String key : keys)
{
MemoryUsage before = info.getGcInfo().getMemoryUsageBeforeGc().get(key);
MemoryUsage after = info.getGcInfo().getMemoryUsageAfterGc().get(key);
if (after != null && after.getUsed() != before.getUsed())
{
sb.append(key).append(": ").append(before.getUsed());
sb.append(" -> ");
sb.append(after.getUsed());
if (!key.equals(keys.get(keys.size() - 1)))
sb.append("; ");
bytes += before.getUsed() - after.getUsed();
}
}
while (true)
{
State prev = state.get();
if (state.compareAndSet(prev, new State(duration, bytes, prev)))
break;
}
String st = sb.toString();
if (duration > MIN_LOG_DURATION)
logger.info(st);
else if (logger.isDebugEnabled())
logger.debug(st);
if (duration > MIN_LOG_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 (info.getGcName().equals("ConcurrentMarkSweep"))
SSTableDeletingTask.rescheduleFailedTasks();
}
}
public State getTotalSinceLastCheck()
{
return state.getAndSet(new State());
}
public double[] getAndResetStats()
{
State state = getTotalSinceLastCheck();
double[] r = new double[6];
r[0] = TimeUnit.NANOSECONDS.toMillis(System.nanoTime() - state.startNanos);
r[1] = state.maxRealTimeElapsed;
r[2] = state.totalRealTimeElapsed;
r[3] = state.sumSquaresRealTimeElapsed;
r[4] = state.totalBytesReclaimed;
r[5] = state.count;
return r;
}
}