org.lsst.ccs.messaging.util

Class MultiQueueDispatcher

java.lang.Object

org.lsst.ccs.messaging.util.AbstractDispatcher

org.lsst.ccs.messaging.util.MultiQueueDispatcher

All Implemented Interfaces:

Dispatcher

public class MultiQueueDispatcher
extends AbstractDispatcher

Dispatcher implementation that decouples message processing by CCS from message processing by JGroups.

Author:

onoprien

Nested Class Summary

Nested classes/interfaces inherited from class org.lsst.ccs.messaging.util.AbstractDispatcher

AbstractDispatcher.Task

Nested classes/interfaces inherited from interface org.lsst.ccs.messaging.util.Dispatcher

Dispatcher.AlertEvent, Dispatcher.Event, Dispatcher.Listener, Dispatcher.Order, Dispatcher.Stage

Field Summary

Fields inherited from class org.lsst.ccs.messaging.util.AbstractDispatcher

alerts, config, serviceExec

Constructor Summary

Constructors

Constructor and Description
MultiQueueDispatcher(String args) Constructs an instance.

Method Summary

Modifier and Type	Method and Description
void	in(Runnable run, Bus bus, String... agents) Submits a task to process an incoming message or disconnection notification.
void	initialize() Initializes this dispatcher.
void	out(Runnable run, Bus bus, Dispatcher.Order order) Submits a task to process an outgoing message.
void	shutdown() Orderly shuts down this dispatcher.

Methods inherited from class org.lsst.ccs.messaging.util.AbstractDispatcher

addListener, deliverEvent, fireEvent, getBooleanArg, getIntArg, getIntArrayArg, getIntArrayArg, getLogger, getRegisteredAlerts, raiseAlert, raiseAlert, registerAlert, removeListener

Methods inherited from class java.lang.Object

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

Constructor Detail

MultiQueueDispatcher

public MultiQueueDispatcher(String args)

Constructs an instance.

Recognized configuration parameters:

inThreads

Number of processing threads for incoming messages: [LOG, COMMAND, STATUS]. Default: [1, 1, 8]

duration/[in|out]/{BUS}/{STAGE}

Logging and alert thresholds for message processing times (in milliseconds): [log, WARNING, ALARM]. Default: [] (no monitoring).

queue/[in|out]/{BUS}

Logging and alert thresholds for queue size: [log, WARNING, ALARM]. Default: [] (no monitoring).

Parameters:

args - Configuration string in "key[=value]&...&key[=value]" format, where value may be a comma-separated array.

Method Detail

initialize

public void initialize()

Initializes this dispatcher. Empty implementation is provided by this class.

Specified by:

initialize in interface Dispatcher

Overrides:

initialize in class AbstractDispatcher

shutdown

public void shutdown()

Orderly shuts down this dispatcher. Stops accepting tasks, executes previously submitted tasks, delivers events to listeners, then shuts down.

Specified by:

shutdown in interface Dispatcher

Overrides:

shutdown in class AbstractDispatcher

in

public void in(Runnable run,
               Bus bus,
               String... agents)

Submits a task to process an incoming message or disconnection notification. This method returns immediately, without waiting for the task to finish execution.

If one or more agent names are given, the task if guaranteed to be executed after any previously submitted tasks for the same bus and agent. If no agents are specified, the task is independent of other tasks, subject to capacity controls imposed by this service. If the agents argument is null, the task is independent of other tasks, not subject to capacity controls.

Parameters:

run - Task to be executed.

bus - Bus (LOG, STATUS, or COMMAND).

agents - Names of affected agents (source or disconnected).

Throws:

TransportStateException - If this Dispatcher is unable to accept the request for reasons other than being uninitialized or shut down.

out

public void out(Runnable run,
                Bus bus,
                Dispatcher.Order order)

Submits a task to process an outgoing message. This method returns immediately, without waiting for the task to finish execution. If the service has been shut down, calling this method does nothing.

Tasks submitted with outOfBand equal to false for the same bus are guaranteed to be processed in the order of submission. If outOfBand equals true, the task is executed independently of others, subject to capacity controls imposed by this service. If outOfBand equals null, the task is independent, not subject to capacity controls.

Parameters:

run - Task to be executed.

bus - Bus (LOG, STATUS, or COMMAND).

order - Order of execution and capacity control policies.

Throws:

TransportStateException - If this Dispatcher is unable to accept the request for reasons other than being uninitialized or shut down.