org.apache.zookeeper.server.util.OSMXBean Maven / Gradle / Ivy
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* 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.zookeeper.server.util;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.lang.management.ManagementFactory;
import java.lang.management.OperatingSystemMXBean;
import java.lang.management.RuntimeMXBean;
import java.lang.reflect.Method;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
/**
* This class is a wrapper for the implementation of
* com.sun.management.UnixOperatingSystemMXBean
* It will decide to use the sun api or its own implementation
* depending on the runtime (vendor) used.
*/
public class OSMXBean {
private static final Logger LOG = LoggerFactory.getLogger(OSMXBean.class);
private OperatingSystemMXBean osMbean;
private static final boolean ibmvendor = System.getProperty("java.vendor").contains("IBM");
private static final boolean windows = System.getProperty("os.name").startsWith("Windows");
private static final boolean linux = System.getProperty("os.name").startsWith("Linux");
/**
* Constructor. Get the running Operating System instance
*/
public OSMXBean() {
this.osMbean = ManagementFactory.getOperatingSystemMXBean();
}
/**
* Check if the OS is unix. If using the IBM java runtime, this
* will only work for linux.
*
* @return whether this is unix or not.
*/
public boolean getUnix() {
if (windows) {
return false;
}
return (!ibmvendor || linux);
}
/**
* Load the implementation of UnixOperatingSystemMXBean for sun jvm
* and runs the desired method.
* @param mBeanMethodName : method to run from the interface UnixOperatingSystemMXBean
* @return the method result
*/
private Long getOSUnixMXBeanMethod(String mBeanMethodName) {
Object unixos;
Class classRef;
Method mBeanMethod;
try {
classRef = Class.forName("com.sun.management.UnixOperatingSystemMXBean");
if (classRef.isInstance(osMbean)) {
mBeanMethod = classRef.getDeclaredMethod(mBeanMethodName);
unixos = classRef.cast(osMbean);
return (Long) mBeanMethod.invoke(unixos);
}
} catch (Exception e) {
LOG.warn("Not able to load class or method for com.sun.managment.UnixOperatingSystemMXBean.", e);
}
return null;
}
/**
* Get the number of opened filed descriptor for the runtime jvm.
* If sun java, it will use the com.sun.management interfaces.
* Otherwise, this methods implements it (linux only).
* @return number of open file descriptors for the jvm
*/
public long getOpenFileDescriptorCount() {
Long ofdc;
if (!ibmvendor) {
ofdc = getOSUnixMXBeanMethod("getOpenFileDescriptorCount");
return (ofdc != null ? ofdc.longValue() : -1);
}
try {
//need to get the PID number of the process first
RuntimeMXBean rtmbean = ManagementFactory.getRuntimeMXBean();
String rtname = rtmbean.getName();
String[] pidhost = rtname.split("@");
//using linux bash commands to retrieve info
Process p = Runtime.getRuntime()
.exec(new String[]{"bash", "-c", "ls /proc/" + pidhost[0] + "/fdinfo | wc -l"});
InputStream in = p.getInputStream();
BufferedReader output = new BufferedReader(new InputStreamReader(in));
try {
String openFileDesCount;
if ((openFileDesCount = output.readLine()) != null) {
return Long.parseLong(openFileDesCount);
}
} finally {
if (output != null) {
output.close();
}
}
} catch (IOException ie) {
LOG.warn("Not able to get the number of open file descriptors", ie);
}
return -1;
}
/**
* Get the number of the maximum file descriptors the system can use.
* If sun java, it will use the com.sun.management interfaces.
* Otherwise, this methods implements it (linux only).
* @return max number of file descriptors the operating system can use.
*/
public long getMaxFileDescriptorCount() {
Long mfdc;
if (!ibmvendor) {
mfdc = getOSUnixMXBeanMethod("getMaxFileDescriptorCount");
return (mfdc != null ? mfdc.longValue() : -1);
}
try {
//using linux bash commands to retrieve info
Process p = Runtime.getRuntime().exec(new String[]{"bash", "-c", "ulimit -n"});
InputStream in = p.getInputStream();
BufferedReader output = new BufferedReader(new InputStreamReader(in));
try {
String maxFileDesCount;
if ((maxFileDesCount = output.readLine()) != null) {
return Long.parseLong(maxFileDesCount);
}
} finally {
if (output != null) {
output.close();
}
}
} catch (IOException ie) {
LOG.warn("Not able to get the max number of file descriptors", ie);
}
return -1;
}
}