如何使用kill -3 <pid>命令每30秒进行一次jave堆转储

Question

请帮忙,我想运行一个shell脚本,它应该使用kill -3命令每30秒进行一次jave堆转储.提前致谢.

Answer 1

你试过这么简单的shell脚本吗？

while true
do
  jmap -dump:file=/tmp/java-`date +%s`.hprof PID_OF_JVM
  sleep 30
done

这将为每个快照创建一个文件梨.对于线程转储,您可以使用类似的脚本:

while true
do
  jstack PID_OF_JVM > stack-`date +%s`.txt
  sleep 30
done

我想你可以用kill -3而不是jstack.

Answer 2

您可以使用这样的代码从 Java 应用程序进行线程转储

 public static String getDumpFor(Thread thread) {
    StringBuilder sb = new StringBuilder();
    if (thread.isAlive()) {
        StackTraceElement[] stackTrace = thread.getStackTrace();
        sb.append(thread.toString()).append("\n")
                .append(String.format(" State - %s,", thread.getState()))
                .append(String.format(" Is daemon = %s,", thread.isDaemon()));
        for (StackTraceElement s : stackTrace)
            sb.append("\tat ").append(s.getClassName()).append(".").append(s.getMethodName()).append("(").append(s.getFileName()).append(":").append(s.getLineNumber()).append(")")
                    .append("\n");
    }
    return sb.toString();
}


public static void dumpActiveThreads() {
    Map<Thread, StackTraceElement[]> stackTraces = Thread.getAllStackTraces();
    Set<Thread> keySet = stackTraces.keySet();
    System.out.println("\nThread dump begin:");
    for (Thread thread : keySet)
        dumpActiveThread(thread);
    System.out.println("\nThread dump end.");

}

然后像这样安排任务

 final ScheduledFuture<?> scheduledFuture = scheduledExecutorService.scheduleWithFixedDelay(
            new Runnable() {dumpActiveThreads()},
            0,
            30, TimeUnit.SECONDS);