Created
May 20, 2012 14:42
-
-
Save hikoma/2758340 to your computer and use it in GitHub Desktop.
Prints java stack traces of java threads eating the CPU
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
import java.io.IOException; | |
import java.lang.management.ManagementFactory; | |
import java.lang.management.ThreadInfo; | |
import java.lang.management.ThreadMXBean; | |
import java.util.Collections; | |
import java.util.HashMap; | |
import java.util.Map; | |
import javax.management.remote.JMXConnector; | |
import javax.management.remote.JMXConnectorFactory; | |
import javax.management.remote.JMXServiceURL; | |
public class CpuMonitor { | |
private final ThreadMXBean threadMXBean; | |
private int threshold = 95; | |
private int maxDepth = Integer.MAX_VALUE; | |
private long period = 0; | |
private long prevSystemTime = 0; | |
private Map<Long, Long> prevCpuTimes = Collections.emptyMap(); | |
public CpuMonitor() { | |
threadMXBean = ManagementFactory.getThreadMXBean(); | |
} | |
public CpuMonitor(String serviceUrl) throws IOException { | |
if (serviceUrl == null) { | |
threadMXBean = ManagementFactory.getThreadMXBean(); | |
} else { | |
JMXConnector connector = JMXConnectorFactory.connect(new JMXServiceURL(serviceUrl)); | |
threadMXBean = ManagementFactory.newPlatformMXBeanProxy(connector.getMBeanServerConnection(), | |
ManagementFactory.THREAD_MXBEAN_NAME, ThreadMXBean.class); | |
} | |
} | |
public final void setThreshold(int threshold) { | |
this.threshold = threshold; | |
} | |
public final void setMaxDepth(int maxDepth) { | |
this.maxDepth = maxDepth; | |
} | |
public final void process() { | |
init(); | |
Map<Long, Long> currentCpuTimes = new HashMap<Long, Long>(); | |
long currentSystemTime = System.nanoTime(); | |
long diff = (currentSystemTime - prevSystemTime) / 100; | |
for (long id : threadMXBean.getAllThreadIds()) { | |
long cpuTime = threadMXBean.getThreadCpuTime(id); | |
if (prevCpuTimes.containsKey(id)) { | |
long cpuUsage = (cpuTime - prevCpuTimes.get(id)) / diff; | |
if (cpuUsage >= threshold) { | |
handle(period, cpuUsage, threadMXBean.getThreadInfo(id, maxDepth)); | |
} | |
} | |
currentCpuTimes.put(id, cpuTime); | |
} | |
period++; | |
prevSystemTime = currentSystemTime; | |
prevCpuTimes = currentCpuTimes; | |
} | |
protected void init() { | |
} | |
protected void handle(long period, long cpuUsage, ThreadInfo threadInfo) { | |
System.out.println("[" + cpuUsage + "%] " + threadInfo); | |
} | |
public static void main(String[] args) throws InterruptedException, IOException { | |
CpuMonitor monitor = new CpuMonitor(System.getProperty("serviceUrl")); | |
if (args.length >= 1) { | |
monitor.setThreshold(Integer.valueOf(args[0])); | |
} | |
while (true) { | |
monitor.process(); | |
Thread.sleep(10000); // 10 seconds | |
} | |
} | |
} |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment