org.apache.flink.runtime.taskmanager

Class MemoryLogger

java.lang.Object

java.lang.Thread

org.apache.flink.runtime.taskmanager.MemoryLogger

All Implemented Interfaces:

Runnable

public class MemoryLogger
extends Thread

A thread the periodically logs statistics about:

• Heap and non-heap memory usage
• Memory pools and pool usage
• Garbage collection times and counts

Nested Class Summary

Nested classes/interfaces inherited from class java.lang.Thread

Thread.State, Thread.UncaughtExceptionHandler

Field Summary

Fields inherited from class java.lang.Thread

MAX_PRIORITY, MIN_PRIORITY, NORM_PRIORITY

Constructor Summary

Constructors

Constructor and Description
MemoryLogger(org.slf4j.Logger logger, long interval, akka.actor.ActorSystem monitored) Creates a new memory logger that logs in the given interval and lives as long as the given actor system.

Method Summary

Methods

Modifier and Type	Method and Description
static String	getGarbageCollectorStatsAsString(List<GarbageCollectorMXBean> gcMXBeans) Gets the garbage collection statistics from the JVM.
static String	getMemoryPoolStatsAsString(List<MemoryPoolMXBean> poolBeans) Gets the memory pool statistics from the JVM.
static String	getMemoryUsageStatsAsString(MemoryMXBean memoryMXBean) Gets the memory footprint of the JVM in a string representation.
void	run()
void	shutdown()

Methods inherited from class java.lang.Thread

activeCount, checkAccess, clone, countStackFrames, currentThread, destroy, dumpStack, enumerate, getAllStackTraces, getContextClassLoader, getDefaultUncaughtExceptionHandler, getId, getName, getPriority, getStackTrace, getState, getThreadGroup, getUncaughtExceptionHandler, holdsLock, interrupt, interrupted, isAlive, isDaemon, isInterrupted, join, join, join, resume, setContextClassLoader, setDaemon, setDefaultUncaughtExceptionHandler, setName, setPriority, setUncaughtExceptionHandler, sleep, sleep, start, stop, stop, suspend, toString, yield

Methods inherited from class java.lang.Object

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

Constructor Detail

MemoryLogger

public MemoryLogger(org.slf4j.Logger logger,
            long interval,
            akka.actor.ActorSystem monitored)

Creates a new memory logger that logs in the given interval and lives as long as the given actor system.

Parameters:

logger - The logger to use for outputting the memory statistics.

interval - The interval in which the thread logs.

monitored - The actor system to whose life the thread is bound. The thread terminates once the actor system terminates.

Method Detail

shutdown

public void shutdown()

run

public void run()

Specified by:

run in interface Runnable

Overrides:

run in class Thread

getMemoryUsageStatsAsString

public static String getMemoryUsageStatsAsString(MemoryMXBean memoryMXBean)

Gets the memory footprint of the JVM in a string representation.

Returns:

A string describing how much heap memory and direct memory are allocated and used.

getMemoryPoolStatsAsString

public static String getMemoryPoolStatsAsString(List<MemoryPoolMXBean> poolBeans)

Gets the memory pool statistics from the JVM.

Parameters:

poolBeans - The collection of memory pool beans.

Returns:

A string denoting the names and sizes of the memory pools.

getGarbageCollectorStatsAsString

public static String getGarbageCollectorStatsAsString(List<GarbageCollectorMXBean> gcMXBeans)

Gets the garbage collection statistics from the JVM.

Parameters:

gcMXBeans - The collection of garbage collector beans.

Returns:

A string denoting the number of times and total elapsed time in garbage collection.