stormpot

Interface ManagedPool

All Known Implementing Classes:

BlazePool, BlazePool, QueuePool, QueuePool

@MXBean
public interface ManagedPool

This is the JMX management interface for Stormpot object pools.

Using this interface, pools can be exposed to external management as an MXBean. Since its an MXBean, and not just an MBean, it imposes no requirement that external parties knows about the Stormpot types.

Once you have created your pool, it is easy to expose it through the platform MBeanServer, or any MBeanServer you like:

BlazePool<MyPoolable> pool = new BlazePool<MyPoolable>(...);
MBeanServer server = ManagementFactory.getPlatformMBeanServer();
ObjectName name = new ObjectName("com.myapp:objectpool=stormpot");
server.registerMBean(pool, name);

Using the platform MBeanServer will make the pool visible to tools like JConsole and VisualVM.

Since:

2.3

Method Summary

Methods

Modifier and Type	Method and Description
long	getAllocationCount() Return the number of objects the pool has allocated since it was created.
double	getAllocationFailureLatencyPercentile(double percentile)
double	getAllocationLatencyPercentile(double percentile)
double	getDeallocationLatencyPercentile(double percentile)
long	getFailedAllocationCount() Return the number of allocations that has failed, either because the allocator threw an exception or because it returned null, since the pool was created.
long	getLeakedObjectsCount() If the pool is capable of precise object leak detection, this method will return the number of object leaks that have been detected, and prevented, since the pool was created.
double	getObjectLifetimePercentile(double percentile)
double	getReallocationFailureLatencyPercentile(double percentile)
double	getReallocationLatencyPercentile(double percentile)
int	getTargetSize()
boolean	isShutDown() Returns 'true' if the shut down process has been started on this pool, 'false' otherwise.
void	setTargetSize(int size)

Method Detail

getAllocationCount

long getAllocationCount()

Return the number of objects the pool has allocated since it was created.

Returns:

The number of Poolable objects ever created by this pool.

getFailedAllocationCount

long getFailedAllocationCount()

Return the number of allocations that has failed, either because the allocator threw an exception or because it returned null, since the pool was created.

Returns:

The number of allocations that have failed for one reason or another.

getLeakedObjectsCount

long getLeakedObjectsCount()

If the pool is capable of precise object leak detection, this method will return the number of object leaks that have been detected, and prevented, since the pool was created. If the pool does not support precise object leak detection, then this method returns -1.

There are two kinds of leaks: One where the application forgets to release an object back to the pool, but keeps a strong reference to the object, and another where the application not only forgets to release the object, but also looses the reference to the object, making it eligible for garbage collection. The precise leak detector will only count leaks of the latter kind, where the leaked object has been garbage collected.

Returns:

The number of objects leaked from the users of this pool, since the pool was created, or -1 if the pool does not implement precise leak detection.

setTargetSize

void setTargetSize(int size)

Parameters:

size - The new target size.

See Also:

ResizablePool.setTargetSize(int)

getTargetSize

int getTargetSize()

Returns:

The current target size.

See Also:

ResizablePool.getTargetSize()

isShutDown

boolean isShutDown()

Returns 'true' if the shut down process has been started on this pool, 'false' otherwise. This method does not reveal whether or not the shut down process has completed.

Returns:

'true' if LifecycledPool.shutdown() has been called on this pool.

getObjectLifetimePercentile

double getObjectLifetimePercentile(double percentile)

Parameters:

percentile - The percentile to get, as a decimal, e.g. a number between 0.0 and 1.0.

Returns:

The approximate object lifetime in milliseconds, for the given percentile, or Double.NaN if no MetricsRecorder has been configured for the pool.

See Also:

MetricsRecorder.getObjectLifetimePercentile(double)

getAllocationLatencyPercentile

double getAllocationLatencyPercentile(double percentile)

Parameters:

percentile - The percentile to get, as a decimal, e.g. a number between 0.0 and 1.0.

Returns:

The approximate latency for allocations in milliseconds, for the given percentile, or Double.NaN if no MetricsRecorder has been configured for the pool.

See Also:

MetricsRecorder.getAllocationLatencyPercentile(double)

getAllocationFailureLatencyPercentile

double getAllocationFailureLatencyPercentile(double percentile)

Parameters:

percentile - The percentile to get, as a decimal, e.g. a number between 0.0 and 1.0.

Returns:

The approximate latency for failed allocations in milliseconds, for the given percentile, or Double.NaN if no MetricsRecorder has been configured for the pool.

See Also:

MetricsRecorder.getAllocationFailureLatencyPercentile(double)

getReallocationLatencyPercentile

double getReallocationLatencyPercentile(double percentile)

Parameters:

percentile - The percentile to get, as a decimal, e.g. a number between 0.0 and 1.0.

Returns:

The approximate latency for reallocations in milliseconds, for the given percentile, or Double.NaN if no MetricsRecorder has been configured for the pool.

See Also:

MetricsRecorder.getReallocationLatencyPercentile(double)

getReallocationFailureLatencyPercentile

double getReallocationFailureLatencyPercentile(double percentile)

Parameters:

percentile - The percentile to get, as a decimal, e.g. a number between 0.0 and 1.0.

Returns:

The approximate latency for failed reallocations in milliseconds, for the given percentile, or Double.NaN if no MetricsRecorder has been configured for the pool.

See Also:

MetricsRecorder.getReallocationFailurePercentile(double)

getDeallocationLatencyPercentile

double getDeallocationLatencyPercentile(double percentile)

Parameters:

percentile - The percentile to get, as a decimal, e.g. a number between 0.0 and 1.0.

Returns:

The approximate latency for deallocations, regardless of whether the throw exceptions or not, in milliseconds for the given percentile, or Double.NaN if no MetricsRecorder has been configured for the pool.

See Also:

MetricsRecorder.getDeallocationLatencyPercentile(double)