io.druid.java.util.metrics.JvmPidDiscoverer Maven / Gradle / Ivy
/*
* Licensed to Metamarkets Group Inc. (Metamarkets) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. Metamarkets 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 io.druid.java.util.metrics;
import io.druid.java.util.common.RE;
import java.lang.management.ManagementFactory;
import java.util.regex.Pattern;
/**
* For systems that for whatever reason cannot use Sigar (through io.druid.java.util.metrics.SigarPidDiscoverer ),
* this attempts to get the PID from the JVM "name".
*/
public class JvmPidDiscoverer implements PidDiscoverer
{
private static final JvmPidDiscoverer INSTANCE = new JvmPidDiscoverer();
public static JvmPidDiscoverer instance()
{
return INSTANCE;
}
/**
* use {JvmPidDiscoverer.instance()}
*/
private JvmPidDiscoverer()
{
}
/**
* Returns the PID as a best guess. This uses methods that are not guaranteed to actually be the PID.
*
* TODO: switch to ProcessHandle.current().getPid() for java9 potentially
*
* @return the PID of the current jvm if available
*
* @throws RuntimeException if the pid cannot be determined
*/
@Override
public long getPid()
{
return Inner.PID;
}
private static class Inner
{
private static final long PID;
static {
final String jvmName = ManagementFactory.getRuntimeMXBean().getName();
final String[] nameSplits = jvmName.split(Pattern.quote("@"));
if (nameSplits.length != 2) {
throw new RE("Unable to determine pid from [%s]", jvmName);
}
try {
PID = Long.parseLong(nameSplits[0]);
}
catch (NumberFormatException nfe) {
throw new RE(nfe, "Unable to determine pid from [%s]", jvmName);
}
}
}
}