mondrian.rolap

Class RolapResultShepherd

java.lang.Object

mondrian.rolap.RolapResultShepherd

public class RolapResultShepherd
extends Object

A utility class for RolapConnection. It specializes in shepherding the creation of RolapResult by running the actual execution on a separate thread from the user thread so we can:

• Monitor all executions for timeouts and resource limits as they run in the background
• Bubble exceptions to the user thread as fast as they happen.
• Gracefully cancel all SQL statements and cleanup in the background.

Author:

LBoudreau

Constructor Summary

Constructors

Constructor and Description
RolapResultShepherd()

Method Summary

Modifier and Type	Method and Description
Result	shepherdExecution(Execution execution, Callable<Result> callable) Executes and shepherds the execution of an Execution instance.
void	shutdown()

Methods inherited from class java.lang.Object

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

Constructor Detail

RolapResultShepherd

public RolapResultShepherd()

Method Detail

shepherdExecution

public Result shepherdExecution(Execution execution,
                                Callable<Result> callable)

Executes and shepherds the execution of an Execution instance. The shepherd will wrap the Execution instance into a Future object which can be monitored for exceptions. If any are encountered, two things will happen. First, the user thread will be returned and the resulting exception will bubble up. Second, the execution thread will attempt to do a graceful stop of all running SQL statements and release all other resources gracefully in the background.

Parameters:

execution - An Execution instance.

callable - A callable to monitor returning a Result instance.

Returns:

A Result object, as supplied by the Callable passed as a parameter.

Throws:

ResourceLimitExceededException - if some resource limit specified in the property file was exceeded

QueryCanceledException - if query was canceled during execution

QueryTimeoutException - if query exceeded timeout specified in the property file

shutdown

public void shutdown()