org.apache.hadoop.util
Class ProcfsBasedProcessTree

java.lang.Object
  org.apache.hadoop.util.ProcfsBasedProcessTree

public class ProcfsBasedProcessTree
extends Object

A Proc file-system based ProcessTree. Works only on Linux.

Field Summary

static long

DEFAULT_SLEEPTIME_BEFORE_SIGKILL

Constructor Summary

ProcfsBasedProcessTree(String pid)

ProcfsBasedProcessTree(String pid, String procfsDir)

Method Summary

void	destroy() Destroy the process-tree.
long	getCumulativeVmem() Get the cumulative virtual memory used by all the processes in the process-tree.
long	getCumulativeVmem(int olderThanAge) Get the cumulative virtual memory used by all the processes in the process-tree that are older than the passed in age.
static String	getPidFromPidFile(String pidFileName) Get PID from a pid-file.
ProcfsBasedProcessTree	getProcessTree() Get the process-tree with latest state.
boolean	isAlive() Is the process-tree alive? Currently we care only about the status of the root-process.
static boolean	isAvailable() Checks if the ProcfsBasedProcessTree is available on this system.
void	setSigKillInterval(long interval)
String	toString() Returns a string printing PIDs of process present in the ProcfsBasedProcessTree.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Field Detail

DEFAULT_SLEEPTIME_BEFORE_SIGKILL

public static final long DEFAULT_SLEEPTIME_BEFORE_SIGKILL

See Also:

Constant Field Values

Constructor Detail

ProcfsBasedProcessTree

public ProcfsBasedProcessTree(String pid)

ProcfsBasedProcessTree

public ProcfsBasedProcessTree(String pid,
                              String procfsDir)

Method Detail

setSigKillInterval

public void setSigKillInterval(long interval)

isAvailable

public static boolean isAvailable()

Checks if the ProcfsBasedProcessTree is available on this system.

Returns:

true if ProcfsBasedProcessTree is available. False otherwise.

getProcessTree

public ProcfsBasedProcessTree getProcessTree()

Get the process-tree with latest state. If the root-process is not alive, an empty tree will be returned.

Returns:

the process-tree with latest state.

isAlive

public boolean isAlive()

Is the process-tree alive? Currently we care only about the status of the root-process.

Returns:

true if the process-true is alive, false otherwise.

destroy

public void destroy()

Destroy the process-tree. Currently we only make sure the root process is gone. It is the responsibility of the root process to make sure that all its descendants are cleaned up.

getCumulativeVmem

public long getCumulativeVmem()

Get the cumulative virtual memory used by all the processes in the process-tree.

Returns:

cumulative virtual memory used by the process-tree in bytes.

getCumulativeVmem

public long getCumulativeVmem(int olderThanAge)

Get the cumulative virtual memory used by all the processes in the process-tree that are older than the passed in age.

Parameters:

olderThanAge - processes above this age are included in the memory addition

Returns:

cumulative virtual memory used by the process-tree in bytes, for processes older than this age.

getPidFromPidFile

public static String getPidFromPidFile(String pidFileName)

Get PID from a pid-file.

Parameters:

pidFileName - Name of the pid-file.

Returns:

the PID string read from the pid-file. Returns null if the pidFileName points to a non-existing file or if read fails from the file.

toString

public String toString()

Returns a string printing PIDs of process present in the ProcfsBasedProcessTree. Output format : [pid pid ..]

Overrides:

toString in class Object