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eldritchideen/GCMonitoring.java

Forked from lichengwu/GCMonitoring.java
Created May 1, 2014 03:19
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GCMonitoring.java
/**
* gc monitoring only on jdk7 or later
*
* @author lichengwu
* @version 1.0
* @created 2013-09-14 10:44 PM
*/
public class GCMonitoring {
private static final long JVM_START_TIME = ManagementFactory.getRuntimeMXBean().getStartTime();
private static DateFormat dateFormat = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss.SSS");
private static final long ONE_BYTE = 1024;
public static void init() {
//get all GarbageCollectorMXBeans
List<GarbageCollectorMXBean> gcBeans = ManagementFactory.getGarbageCollectorMXBeans();
//register every GarbageCollectorMXBean
for (GarbageCollectorMXBean gcBean : gcBeans) {
System.out.println(
"register " + gcBean.getName() + " for " + Arrays.deepToString(gcBean.getMemoryPoolNames()));
NotificationEmitter emitter = (NotificationEmitter) gcBean;
//new listener
NotificationListener listener = new NotificationListener() {
//record total gc time spend
long totalGcTimeSpend = 0;
@Override
public void handleNotification(Notification notification, Object handback) {
HandBack handBack = (HandBack) handback;
//get gc info
GarbageCollectionNotificationInfo info =
GarbageCollectionNotificationInfo.from((CompositeData) notification.getUserData());
//output
String gcType = info.getGcAction();
if (gcType.length() > 7) {
gcType = gcType.substring(7);
}
//get a glance of gc
StringBuilder gcGlance = new StringBuilder();
gcGlance.append(gcType).append(": - ").append(info.getGcInfo().getId());
gcGlance.append(" (").append(info.getGcCause()).append(") ");
gcGlance.append("start: ")
.append(dateFormat.format(new Date(JVM_START_TIME + info.getGcInfo().getStartTime())));
gcGlance.append(", end: ")
.append(dateFormat.format(new Date(JVM_START_TIME + info.getGcInfo().getEndTime())));
System.out.println(gcGlance.toString());
//memory info
Map<String, MemoryUsage> beforeUsageMap = info.getGcInfo().getMemoryUsageBeforeGc();
Map<String, MemoryUsage> afterUsageMap = info.getGcInfo().getMemoryUsageAfterGc();
for (Map.Entry<String, MemoryUsage> entry : afterUsageMap.entrySet()) {
String name = entry.getKey();
MemoryUsage afterUsage = entry.getValue();
MemoryUsage beforeUsage = beforeUsageMap.get(name);
StringBuilder usage = new StringBuilder();
usage.append("\t[").append(name).append("] ");
usage.append("init:").append(afterUsage.getInit() / ONE_BYTE).append("K; ");
usage.append("used:").append(handBack
.handUsage(beforeUsage.getUsed(), afterUsage.getUsed(), beforeUsage.getMax()))
.append("; ");
usage.append("committed: ").append(handBack
.handUsage(beforeUsage.getCommitted(), afterUsage.getCommitted(),
beforeUsage.getMax()));
System.out.println(usage.toString());
}
totalGcTimeSpend += info.getGcInfo().getDuration();
//summary
long percent =
(info.getGcInfo().getEndTime() - totalGcTimeSpend) * 1000L / info.getGcInfo().getEndTime();
StringBuilder summary = new StringBuilder();
summary.append("duration:").append(info.getGcInfo().getDuration()).append("ms");
summary.append(", throughput:").append((percent / 10)).append(".").append(percent % 10).append('%');
System.out.println(summary.toString());
System.out.println();
}
};
//add the listener
emitter.addNotificationListener(listener, new NotificationFilter() {
private static final long serialVersionUID = 3763793138186359389L;
@Override
public boolean isNotificationEnabled(Notification notification) {
//filter GC notification
return notification.getType()
.equals(GarbageCollectionNotificationInfo.GARBAGE_COLLECTION_NOTIFICATION);
}
}, HandBack.getInstance());
}
}
private static class HandBack {
private HandBack() {
}
private static HandBack instance = new HandBack();
public static HandBack getInstance() {
return instance;
}
public String handUsage(long before, long after, long max) {
StringBuilder usage = new StringBuilder();
if (max == -1) {
usage.append("").append(before / ONE_BYTE).append("K -> ").append(after / ONE_BYTE).append("K)");
return usage.toString();
}
long beforePercent = ((before * 1000L) / max);
long afterPercent = ((after * 1000L) / max);
usage.append(beforePercent / 10).append('.').append(beforePercent % 10).append("%(")
.append(before / ONE_BYTE).append("K) -> ").append(afterPercent / 10).append('.')
.append(afterPercent % 10).append("%(").append(after / ONE_BYTE).append("K)");
return usage.toString();
}
}
}
Raw
output
register G1 Young Generation for [G1 Eden Space, G1 Survivor Space]
register G1 Old Generation for [G1 Eden Space, G1 Survivor Space, G1 Old Gen, G1 Perm Gen]
major GC: - 1 (System.gc()) start: 2013-09-15 09:38:35.193, end: 2013-09-15 09:38:59.283
[G1 Eden Space] init:26624K; used:3072K -> 4096K); committed: 26624K -> 26624K)
[G1 Old Gen] init:97280K; used:0.0%(0K) -> 0.0%(0K); committed: 4.9%(97280K) -> 4.9%(97280K)
[Code Cache] init:2496K; used:0.8%(433K) -> 0.8%(433K); committed: 5.0%(2496K) -> 5.0%(2496K)
[G1 Perm Gen] init:20480K; used:5.9%(5012K) -> 5.9%(5012K); committed: 24.3%(20480K) -> 24.3%(20480K)
[G1 Survivor Space] init:0K; used:0K -> 0K); committed: 0K -> 0K)
duration:24090ms, throughput:87.3%
minor GC: - 1 (G1 Humongous Allocation) start: 2013-09-15 09:38:59.618, end: 2013-09-15 09:39:00.870
[G1 Eden Space] init:26624K; used:0K -> 1024K); committed: 4096K -> 4096K)
[G1 Old Gen] init:97280K; used:0.1%(1990K) -> 0.1%(1990K); committed: 0.1%(3072K) -> 0.1%(3072K)
[Code Cache] init:2496K; used:0.8%(433K) -> 0.8%(433K); committed: 5.0%(2496K) -> 5.0%(2496K)
[G1 Perm Gen] init:20480K; used:5.9%(5017K) -> 5.9%(5017K); committed: 24.3%(20480K) -> 24.3%(20480K)
[G1 Survivor Space] init:0K; used:0K -> 0K); committed: 0K -> 0K)
duration:1252ms, throughput:99.3%
minor GC: - 2 (G1 Humongous Allocation) start: 2013-09-15 09:39:21.662, end: 2013-09-15 09:39:23.649
[G1 Eden Space] init:26624K; used:1024K -> 1024K); committed: 2048K -> 2048K)
[G1 Old Gen] init:97280K; used:1.8%(35814K) -> 1.8%(35814K); committed: 3.7%(73728K) -> 3.7%(73728K)
[Code Cache] init:2496K; used:0.8%(437K) -> 0.8%(437K); committed: 5.0%(2496K) -> 5.0%(2496K)
[G1 Perm Gen] init:20480K; used:6.5%(5487K) -> 6.5%(5487K); committed: 24.3%(20480K) -> 24.3%(20480K)
[G1 Survivor Space] init:0K; used:1024K -> 1024K); committed: 1024K -> 1024K)
duration:1987ms, throughput:98.4%
minor GC: - 3 (G1 Humongous Allocation) start: 2013-09-15 09:39:42.826, end: 2013-09-15 09:39:46.322
[G1 Eden Space] init:26624K; used:1024K -> 1024K); committed: 45056K -> 45056K)
[G1 Old Gen] init:97280K; used:1.8%(35910K) -> 1.8%(35910K); committed: 5.5%(109568K) -> 5.5%(109568K)
[Code Cache] init:2496K; used:0.8%(440K) -> 0.8%(440K); committed: 5.0%(2496K) -> 5.0%(2496K)
[G1 Perm Gen] init:20480K; used:6.5%(5533K) -> 6.5%(5533K); committed: 24.3%(20480K) -> 24.3%(20480K)
[G1 Survivor Space] init:0K; used:1024K -> 1024K); committed: 1024K -> 1024K)
duration:3496ms, throughput:97.1%
Process finished with exit code 0
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