org.apache.hive.http.StackServlet Maven / Gradle / Ivy
/*
* 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.hive.http;
import java.io.IOException;
import java.io.PrintStream;
import java.lang.management.ManagementFactory;
import java.lang.management.ThreadInfo;
import java.lang.management.ThreadMXBean;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
/**
* A servlet to print out the current stack traces.
*/
public class StackServlet extends HttpServlet {
private static final long serialVersionUID = 1L;
private static ThreadMXBean threadBean =
ManagementFactory.getThreadMXBean();
@Override
public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
if (!HttpServer.isInstrumentationAccessAllowed(getServletContext(),
request, response)) {
return;
}
response.setContentType("text/plain; charset=UTF-8");
try (PrintStream out = new PrintStream(
response.getOutputStream(), false, "UTF-8")) {
printThreadInfo(out, "");
}
}
/**
* Print all of the thread's information and stack traces.
*
* @param stream the stream to
* @param title a string title for the stack trace
*/
private synchronized void printThreadInfo(
PrintStream stream, String title) {
final int STACK_DEPTH = 20;
boolean contention = threadBean.isThreadContentionMonitoringEnabled();
long[] threadIds = threadBean.getAllThreadIds();
stream.println("Process Thread Dump: " + title);
stream.println(threadIds.length + " active threads");
for (long tid : threadIds) {
ThreadInfo info = threadBean.getThreadInfo(tid, STACK_DEPTH);
if (info == null) {
stream.println(" Inactive");
continue;
}
stream.println("Thread " +
getTaskName(info.getThreadId(), info.getThreadName()) + ":");
Thread.State state = info.getThreadState();
stream.println(" State: " + state);
stream.println(" Blocked count: " + info.getBlockedCount());
stream.println(" Waited count: " + info.getWaitedCount());
if (contention) {
stream.println(" Blocked time: " + info.getBlockedTime());
stream.println(" Waited time: " + info.getWaitedTime());
}
if (state == Thread.State.WAITING) {
stream.println(" Waiting on " + info.getLockName());
} else if (state == Thread.State.BLOCKED) {
stream.println(" Blocked on " + info.getLockName());
stream.println(" Blocked by " +
getTaskName(info.getLockOwnerId(), info.getLockOwnerName()));
}
stream.println(" Stack:");
for (StackTraceElement frame : info.getStackTrace()) {
stream.println(" " + frame.toString());
}
}
stream.flush();
}
private String getTaskName(long id, String name) {
if (name == null) {
return Long.toString(id);
}
return id + " (" + name + ")";
}
}