Package nz.org.riskscape.engine

Class MemoryMonitoring

java.lang.Object

nz.org.riskscape.engine.MemoryMonitoring

public class MemoryMonitoring
extends Object

A Gauge returning a string indicating whether memory usage is within a certain band = a PoC to see whether we can detect low memory situations reliable

NB - tends to report false low memory situations, as the standard saw tooth behaviour of the jvm's memory use will trip the gauge, even though a GC will reclaim the memory. Hard to know if this matters, but if code just uses this gauge to manage caches, it's probably fine. Maybe see about using the technique in http://www.fasterj.com/articles/gcnotifs.shtml

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static enum	MemoryMonitoring.Level

Field Summary

Fields

Modifier and Type	Field	Description
final float	badRatio
final float	postFullGCbadRatio
final float	postFullGCwarningRatio
final float	warningRatio

Constructor Summary

Constructors

Constructor	Description
MemoryMonitoring()

Method Summary

Modifier and Type	Method	Description
protected static String	formatBytes(long numBytes)
com.codahale.metrics.Gauge<MemoryMonitoring.Level>	getCurrentHeapFreeLevel()
com.codahale.metrics.Gauge<MemoryMonitoring.Level>	getPostFullGCHeapFreeLevel()

Methods inherited from class java.lang.Object

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

Field Details

warningRatio

public final float warningRatio

See Also:

• Constant Field Values

badRatio

public final float badRatio

See Also:

• Constant Field Values

postFullGCwarningRatio

public final float postFullGCwarningRatio

See Also:

• Constant Field Values

postFullGCbadRatio

public final float postFullGCbadRatio

See Also:

• Constant Field Values

Constructor Details

MemoryMonitoring

public MemoryMonitoring()

Method Details

formatBytes

protected static String formatBytes(long numBytes)

getCurrentHeapFreeLevel

public com.codahale.metrics.Gauge<MemoryMonitoring.Level> getCurrentHeapFreeLevel()

getPostFullGCHeapFreeLevel

public com.codahale.metrics.Gauge<MemoryMonitoring.Level> getPostFullGCHeapFreeLevel()