/**
* 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.hadoop.util;
import java.io.BufferedWriter;
import java.io.File;
import java.io.FileWriter;
import java.io.IOException;
import java.util.Random;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.hadoop.fs.FileUtil;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.util.Shell.ExitCodeException;
import org.apache.hadoop.util.Shell.ShellCommandExecutor;
import junit.framework.TestCase;
public class TestProcfsBasedProcessTree extends TestCase {
private static final Log LOG = LogFactory
.getLog(TestProcfsBasedProcessTree.class);
private static String TEST_ROOT_DIR = new Path(System.getProperty(
"test.build.data", "/tmp")).toString().replace(' ', '+');
private ShellCommandExecutor shexec = null;
private String pidFile;
private String shellScript;
private static final int N = 10; // Controls the RogueTask
private static final int memoryLimit = 15 * 1024 * 1024; // 15MB
private static final long PROCESSTREE_RECONSTRUCTION_INTERVAL =
ProcfsBasedProcessTree.DEFAULT_SLEEPTIME_BEFORE_SIGKILL; // msec
private class RogueTaskThread extends Thread {
public void run() {
try {
String args[] = { "bash", "-c",
"echo $$ > " + pidFile + "; sh " + shellScript + " " + N + ";" };
shexec = new ShellCommandExecutor(args);
shexec.execute();
} catch (ExitCodeException ee) {
LOG.info("Shell Command exit with a non-zero exit code. " + ee);
} catch (IOException ioe) {
LOG.info("Error executing shell command " + ioe);
} finally {
LOG.info("Exit code: " + shexec.getExitCode());
}
}
}
private String getRogueTaskPID() {
File f = new File(pidFile);
while (!f.exists()) {
try {
Thread.sleep(500);
} catch (InterruptedException ie) {
break;
}
}
// read from pidFile
return ProcfsBasedProcessTree.getPidFromPidFile(pidFile);
}
public void testProcessTree() {
try {
if (!ProcfsBasedProcessTree.isAvailable()) {
System.out
.println("ProcfsBasedProcessTree is not available on this system. Not testing");
return;
}
} catch (Exception e) {
LOG.info(StringUtils.stringifyException(e));
return;
}
// create shell script
Random rm = new Random();
File tempFile = new File(this.getName() + "_shellScript_" + rm.nextInt()
+ ".sh");
tempFile.deleteOnExit();
shellScript = tempFile.getName();
// create pid file
tempFile = new File(this.getName() + "_pidFile_" + rm.nextInt() + ".pid");
tempFile.deleteOnExit();
pidFile = tempFile.getName();
// write to shell-script
try {
FileWriter fWriter = new FileWriter(shellScript);
fWriter.write(
"# rogue task\n" +
"sleep 10\n" +
"echo hello\n" +
"if [ $1 -ne 0 ]\n" +
"then\n" +
" sh " + shellScript + " $(($1-1))\n" +
"fi");
fWriter.close();
} catch (IOException ioe) {
LOG.info("Error: " + ioe);
return;
}
Thread t = new RogueTaskThread();
t.start();
String pid = getRogueTaskPID();
LOG.info("Root process pid: " + pid);
ProcfsBasedProcessTree p = new ProcfsBasedProcessTree(pid);
p = p.getProcessTree(); // initialize
try {
while (true) {
LOG.info("ProcessTree: " + p.toString());
long mem = p.getCumulativeVmem();
LOG.info("Memory usage: " + mem + "bytes.");
if (mem > memoryLimit) {
p.destroy();
break;
}
Thread.sleep(PROCESSTREE_RECONSTRUCTION_INTERVAL);
p = p.getProcessTree(); // reconstruct
}
} catch (InterruptedException ie) {
LOG.info("Interrupted.");
}
assertFalse("ProcessTree must have been gone", p.isAlive());
// Not able to join thread sometimes when forking with large N.
try {
t.join(2000);
LOG.info("RogueTaskThread successfully joined.");
} catch (InterruptedException ie) {
LOG.info("Interrupted while joining RogueTaskThread.");
}
// ProcessTree is gone now. Any further calls should be sane.
p = p.getProcessTree();
assertFalse("ProcessTree must have been gone", p.isAlive());
assertTrue("Cumulative vmem for the gone-process is "
+ p.getCumulativeVmem() + " . It should be zero.", p
.getCumulativeVmem() == 0);
assertTrue(p.toString().equals("[ ]"));
}
public static class ProcessStatInfo {
// sample stat in a single line : 3910 (gpm) S 1 3910 3910 0 -1 4194624
// 83 0 0 0 0 0 0 0 16 0 1 0 7852 2408448 88 4294967295 134512640
// 134590050 3220521392 3220520036 10975138 0 0 4096 134234626
// 4294967295 0 0 17 1 0 0
String pid;
String name;
String ppid;
String pgrpId;
String session;
String vmem;
public ProcessStatInfo(String[] statEntries) {
pid = statEntries[0];
name = statEntries[1];
ppid = statEntries[2];
pgrpId = statEntries[3];
session = statEntries[4];
vmem = statEntries[5];
}
// construct a line that mimics the procfs stat file.
// all unused numerical entries are set to 0.
public String getStatLine() {
return String.format("%s (%s) S %s %s %s 0 0 0" +
" 0 0 0 0 0 0 0 0 0 0 0 0 0 %s 0 0 0" +
" 0 0 0 0 0 0 0 0" +
" 0 0 0 0 0",
pid, name, ppid, pgrpId, session, vmem);
}
}
/**
* A basic test that creates a few process directories and writes
* stat files. Verifies that the virtual memory is correctly
* computed.
* @throws IOException if there was a problem setting up the
* fake procfs directories or files.
*/
public void testVirtualMemoryForProcessTree() throws IOException {
// test processes
String[] pids = { "100", "200", "300", "400" };
// create the fake procfs root directory.
File procfsRootDir = new File(TEST_ROOT_DIR, "proc");
try {
setupProcfsRootDir(procfsRootDir);
setupPidDirs(procfsRootDir, pids);
// create stat objects.
// assuming processes 100, 200, 300 are in tree and 400 is not.
ProcessStatInfo[] procInfos = new ProcessStatInfo[4];
procInfos[0] = new ProcessStatInfo(new String[]
{"100", "proc1", "1", "100", "100", "100000"});
procInfos[1] = new ProcessStatInfo(new String[]
{"200", "proc2", "100", "100", "100", "200000"});
procInfos[2] = new ProcessStatInfo(new String[]
{"300", "proc3", "200", "100", "100", "300000"});
procInfos[3] = new ProcessStatInfo(new String[]
{"400", "proc4", "1", "400", "400", "400000"});
writeStatFiles(procfsRootDir, pids, procInfos);
// crank up the process tree class.
ProcfsBasedProcessTree processTree =
new ProcfsBasedProcessTree("100", procfsRootDir.getAbsolutePath());
// build the process tree.
processTree.getProcessTree();
// verify cumulative memory
assertEquals("Cumulative memory does not match",
Long.parseLong("600000"), processTree.getCumulativeVmem());
} finally {
FileUtil.fullyDelete(procfsRootDir);
}
}
/**
* Tests that cumulative memory is computed only for
* processes older than a given age.
* @throws IOException if there was a problem setting up the
* fake procfs directories or files.
*/
public void testVMemForOlderProcesses() throws IOException {
// initial list of processes
String[] pids = { "100", "200", "300", "400" };
// create the fake procfs root directory.
File procfsRootDir = new File(TEST_ROOT_DIR, "proc");
try {
setupProcfsRootDir(procfsRootDir);
setupPidDirs(procfsRootDir, pids);
// create stat objects.
// assuming 100, 200 and 400 are in tree, 300 is not.
ProcessStatInfo[] procInfos = new ProcessStatInfo[4];
procInfos[0] = new ProcessStatInfo(new String[]
{"100", "proc1", "1", "100", "100", "100000"});
procInfos[1] = new ProcessStatInfo(new String[]
{"200", "proc2", "100", "100", "100", "200000"});
procInfos[2] = new ProcessStatInfo(new String[]
{"300", "proc3", "1", "300", "300", "300000"});
procInfos[3] = new ProcessStatInfo(new String[]
{"400", "proc4", "100", "100", "100", "400000"});
writeStatFiles(procfsRootDir, pids, procInfos);
// crank up the process tree class.
ProcfsBasedProcessTree processTree =
new ProcfsBasedProcessTree("100", procfsRootDir.getAbsolutePath());
// build the process tree.
processTree.getProcessTree();
// verify cumulative memory
assertEquals("Cumulative memory does not match",
Long.parseLong("700000"), processTree.getCumulativeVmem());
// write one more process as child of 100.
String[] newPids = { "500" };
setupPidDirs(procfsRootDir, newPids);
ProcessStatInfo[] newProcInfos = new ProcessStatInfo[1];
newProcInfos[0] = new ProcessStatInfo(new String[]
{"500", "proc5", "100", "100", "100", "500000"});
writeStatFiles(procfsRootDir, newPids, newProcInfos);
// check vmem includes the new process.
processTree.getProcessTree();
assertEquals("Cumulative memory does not include new process",
Long.parseLong("1200000"), processTree.getCumulativeVmem());
// however processes older than 1 iteration will retain the older value
assertEquals("Cumulative memory shouldn't have included new process",
Long.parseLong("700000"), processTree.getCumulativeVmem(1));
// one more process
newPids = new String[]{ "600" };
setupPidDirs(procfsRootDir, newPids);
newProcInfos = new ProcessStatInfo[1];
newProcInfos[0] = new ProcessStatInfo(new String[]
{"600", "proc6", "100", "100", "100", "600000"});
writeStatFiles(procfsRootDir, newPids, newProcInfos);
// refresh process tree
processTree.getProcessTree();
// processes older than 2 iterations should be same as before.
assertEquals("Cumulative memory shouldn't have included new processes",
Long.parseLong("700000"), processTree.getCumulativeVmem(2));
// processes older than 1 iteration should not include new process,
// but include process 500
assertEquals("Cumulative memory shouldn't have included new processes",
Long.parseLong("1200000"), processTree.getCumulativeVmem(1));
// no processes older than 3 iterations, this should be 0
assertEquals("Getting non-zero vmem for processes older than 3 iterations",
0L, processTree.getCumulativeVmem(3));
} finally {
FileUtil.fullyDelete(procfsRootDir);
}
}
/**
* Create a directory to mimic the procfs file system's root.
* @param procfsRootDir root directory to create.
* @throws IOException if could not delete the procfs root directory
*/
public static void setupProcfsRootDir(File procfsRootDir)
throws IOException {
// cleanup any existing process root dir.
if (procfsRootDir.exists()) {
assertTrue(FileUtil.fullyDelete(procfsRootDir));
}
// create afresh
assertTrue(procfsRootDir.mkdirs());
}
/**
* Create PID directories under the specified procfs root directory
* @param procfsRootDir root directory of procfs file system
* @param pids the PID directories to create.
* @throws IOException If PID dirs could not be created
*/
public static void setupPidDirs(File procfsRootDir, String[] pids)
throws IOException {
for (String pid : pids) {
File pidDir = new File(procfsRootDir, pid);
pidDir.mkdir();
if (!pidDir.exists()) {
throw new IOException ("couldn't make process directory under " +
"fake procfs");
} else {
LOG.info("created pid dir");
}
}
}
/**
* Write stat files under the specified pid directories with data
* setup in the corresponding ProcessStatInfo objects
* @param procfsRootDir root directory of procfs file system
* @param pids the PID directories under which to create the stat file
* @param procs corresponding ProcessStatInfo objects whose data should be
* written to the stat files.
* @throws IOException if stat files could not be written
*/
public static void writeStatFiles(File procfsRootDir, String[] pids,
ProcessStatInfo[] procs) throws IOException {
for (int i=0; i<pids.length; i++) {
File statFile = new File(new File(procfsRootDir, pids[i]), "stat");
BufferedWriter bw = null;
try {
FileWriter fw = new FileWriter(statFile);
bw = new BufferedWriter(fw);
bw.write(procs[i].getStatLine());
LOG.info("wrote stat file for " + pids[i] +
" with contents: " + procs[i].getStatLine());
} finally {
// not handling exception - will throw an error and fail the test.
if (bw != null) {
bw.close();
}
}
}
}
}