/**
* 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.blur.utils;
import static org.apache.blur.metrics.MetricsConstants.GC_TIMES;
import static org.apache.blur.metrics.MetricsConstants.JVM;
import static org.apache.blur.metrics.MetricsConstants.ORG_APACHE_BLUR;
import java.lang.management.GarbageCollectorMXBean;
import java.lang.management.ManagementFactory;
import java.lang.management.MemoryMXBean;
import java.lang.management.MemoryUsage;
import java.lang.reflect.Method;
import java.util.ArrayList;
import java.util.List;
import java.util.Map;
import java.util.Map.Entry;
import java.util.concurrent.TimeUnit;
import javax.management.Notification;
import javax.management.NotificationFilter;
import javax.management.NotificationListener;
import org.apache.blur.log.Log;
import org.apache.blur.log.LogFactory;
import com.sun.management.GcInfo;
import com.yammer.metrics.Metrics;
import com.yammer.metrics.core.MetricName;
import com.yammer.metrics.core.Timer;
public class GCWatcherJdk7 {
private static final Log LOG = LogFactory.getLog(GCWatcherJdk7.class);
private static final String GET_LAST_GC_INFO = "getLastGcInfo";
private static final long _1_SECOND = TimeUnit.SECONDS.toMillis(1);
private static GCWatcherJdk7 _instance;
private final MemoryMXBean _memoryMXBean;
private final double _ratio;
private final List<GCAction> _actions = new ArrayList<GCAction>();
private final Timer _gcTimes;
private GCWatcherJdk7(double ratio) {
_memoryMXBean = ManagementFactory.getMemoryMXBean();
MetricName gcTimesName = new MetricName(ORG_APACHE_BLUR, JVM, GC_TIMES);
_gcTimes = Metrics.newTimer(gcTimesName, TimeUnit.MILLISECONDS, TimeUnit.SECONDS);
List<GarbageCollectorMXBean> garbageCollectorMXBeans = ManagementFactory.getGarbageCollectorMXBeans();
for (GarbageCollectorMXBean bean : garbageCollectorMXBeans) {
NotificationListener listener = new NotificationListener() {
@Override
public void handleNotification(Notification notification, Object bean) {
GarbageCollectorMXBean garbageCollectorMXBean = (GarbageCollectorMXBean) bean;
GcInfo gcInfo = getGcInfo(garbageCollectorMXBean);
long startTime = gcInfo.getStartTime();
long endTime = gcInfo.getEndTime();
Map<String, MemoryUsage> usageBeforeGc = gcInfo.getMemoryUsageBeforeGc();
Map<String, MemoryUsage> usageAfterGc = gcInfo.getMemoryUsageAfterGc();
long usedBefore = getTotal(usageBeforeGc);
long usedAfter = getTotal(usageAfterGc);
long totalTime = endTime - startTime;
long totalSize = usedBefore - usedAfter;
if (totalTime >= _1_SECOND) {
LOG.info("GC event totalTime spent in GC [{0} ms] collected [{1} bytes]", totalTime, totalSize);
}
_gcTimes.update(totalTime, TimeUnit.MILLISECONDS);
MemoryUsage heapMemoryUsage = _memoryMXBean.getHeapMemoryUsage();
long max = heapMemoryUsage.getMax();
long used = heapMemoryUsage.getUsed();
long upperLimit = (long) (max * _ratio);
if (used > upperLimit) {
LOG.error("----- WARNING !!!! - Heap used [{0}] over limit of [{1}], taking action to avoid an OOM error.",
used, upperLimit);
takeAction();
}
}
private void takeAction() {
synchronized (_actions) {
for (GCAction action : _actions) {
try {
action.takeAction();
} catch (Exception e) {
LOG.error("Unknown error while trying to take action against an OOM [{0}]", e, action);
}
}
}
}
private long getTotal(Map<String, MemoryUsage> memoryUsage) {
long used = 0;
for (Entry<String, MemoryUsage> e : memoryUsage.entrySet()) {
used += e.getValue().getUsed();
}
return used;
}
};
NotificationFilter filter = new NotificationFilter() {
private static final long serialVersionUID = 2971450191223596323L;
@Override
public boolean isNotificationEnabled(Notification notification) {
return true;
}
};
Method method;
try {
method = bean.getClass().getMethod("addNotificationListener",
new Class[] { NotificationListener.class, NotificationFilter.class, Object.class });
method.setAccessible(true);
method.invoke(bean, new Object[] { listener, filter, bean });
} catch (Exception e) {
throw new RuntimeException(e);
}
}
_ratio = ratio;
LOG.info("GCWatcherJdk7 was setup.");
}
public static synchronized void init(double ratio) {
if (_instance == null) {
try {
_instance = new GCWatcherJdk7(ratio);
} catch (Exception e) {
LOG.error("GCWatcher had error initializing", e);
}
} else {
LOG.warn("GCWatcher has already been initialized");
}
}
public static void registerAction(GCAction action) {
GCWatcherJdk7 instance = instance();
if (instance != null) {
synchronized (instance._actions) {
instance._actions.add(action);
}
}
}
public static void shutdown() {
}
private static GCWatcherJdk7 instance() {
return _instance;
}
private GcInfo getGcInfo(GarbageCollectorMXBean bean) {
try {
Method method = bean.getClass().getMethod(GET_LAST_GC_INFO, new Class[] {});
method.setAccessible(true);
return (GcInfo) method.invoke(bean, new Object[] {});
} catch (Exception e) {
throw new RuntimeException(e);
}
}
}