com.kabira.platform.swbuiltin

Class EngineServices

java.lang.Object

com.kabira.platform.swbuiltin.EngineServices

public final class EngineServices
extends java.lang.Object

Engine services

Provides access to engine level services. A transaction is required access this class.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	EngineServices.ThrottleState Throttle state

Method Summary

Methods

Modifier and Type	Method and Description
static int	getEngineInstance() Access engine instance
static java.lang.String	getEngineName() Get the name of this engine.
static java.lang.String	getNodeName() Node name for shared memory
static EngineServices.ThrottleState	getThrottleState() Check the state of throttling
static boolean	isStopping() Determine if engine is shutting down
static void	stop(int returnCode) Schedule the current engine to exit
static EngineServices.ThrottleState	throttle() Throttle incoming work if necessary

Methods inherited from class java.lang.Object

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

Method Detail

isStopping

public static final boolean isStopping()

Determine if engine is shutting down

Returns:

true if engine is exiting, false otherwise

This operation can be used to determine if the engine is currently being shut down. When an engine is being shutdown, this operation will return true to indicate that a spawned thread or dispatched operation should stop execution. If a thread does not use this operation to determine when it should exit, the engine will hang and eventually it will be killed by the coordinator causing a non-recoverable node failure.

stop

public static final void stop(int returnCode)

Schedule the current engine to exit

Parameters:

returnCode - Return value for engine

This operation is used to schedule the exit of an engine. This operation only schedules the engine to exit at some later time. It returns to the caller immediately.

A non-zero returnCode value will cause the coordinator to mark node as failed and remove the node's shared memory upon restart.

The node is marked failed if the engine does not exit within the configured engine abort timer after calling stop.

getEngineName

public static final java.lang.String getEngineName()

Get the name of this engine.

Returns:

The name of this engine.

getNodeName

public static final java.lang.String getNodeName()

Node name for shared memory

Returns:

The node name of the shared memory

Get the node name associated with the shared memory that this engine is running against.

getEngineInstance

public static final int getEngineInstance()

Access engine instance

Returns:

The engine instance

Get the engine instance for the engine. All engines on a node have a unique engine instance number.

throttle

public static final EngineServices.ThrottleState throttle()

Throttle incoming work if necessary

Returns:

Current throttle state

If the percentage of shared memory in use exceeds the configured throttle threshold (50% by default), the throttle operation will block a little to slow down incoming work. Throttled is returned from the operation when in this state. When shared memory utilization becomes critical (80% by default) Stall is returned from the throttle operation after blocking for a longer period of time. The application should stop accepting incoming work at this point and attempt to complete processing already accepted work to clear shared memory space.

getThrottleState

public static final EngineServices.ThrottleState getThrottleState()

Check the state of throttling

Returns:

Current throttle state

Get the current throttle state.