org.apache.synapse.endpoints

Class SALoadbalanceEndpoint

java.lang.Object

org.apache.synapse.FaultHandler

org.apache.synapse.endpoints.AbstractEndpoint

org.apache.synapse.endpoints.LoadbalanceEndpoint

org.apache.synapse.endpoints.SALoadbalanceEndpoint

All Implemented Interfaces:

Endpoint, ManagedLifecycle, Nameable, PropertyInclude, SynapseArtifact

public class SALoadbalanceEndpoint
extends LoadbalanceEndpoint

SALoadbalanceEndpoint supports session affinity based load balancing. Each of this endpoint maintains a list of dispatchers. These dispatchers will be updated for both request (for client initiated sessions) and response (for server initiated sessions). Once updated, each dispatcher will check if has already encountered that session. If not, it will update the session -> endpoint map. To update sessions for response messages, all SALoadbalanceEndpoint objects are kept in a global property. When a message passes through SALoadbalanceEndpoints, each endpoint appends its "Synapse unique ID" to the operation context. Once the response for that message arrives, response sender checks first endpoint of the endpoint sequence from the operation context and get that endpoint from the above mentioned global property. Then it will invoke updateSession(...) method of that endpoint. After that, each endpoint will call updateSession(...) method of their appropriate child endpoint, so that all the sending endpoints for the session will be updated.

This endpoint gets the target endpoint first from the dispatch manager, which will ask all listed dispatchers for a matching session. If a matching session is found it will just invoke the send(...) method of that endpoint. If not it will find an endpoint using the load balancing policy and send to that endpoint.

Field Summary

Fields inherited from class org.apache.synapse.endpoints.AbstractEndpoint

anonymous, errorHandler, fileName, initialized, isClusteringEnabled, log, trace

Constructor Summary

Constructors

Constructor and Description
SALoadbalanceEndpoint()

Method Summary

Modifier and Type	Method and Description
Dispatcher	getDispatcher()
long	getSessionTimeout()
void	init(SynapseEnvironment synapseEnvironment) This method should implement the initialization of the implemented parts of the configuration.
void	onChildEndpointFail(Endpoint endpoint, MessageContext synCtx) It is logically incorrect to failover a session affinity endpoint after the session has started.
void	send(MessageContext synCtx) Sends the message context according to an endpoint specific behavior.
void	setDispatcher(Dispatcher dispatcher)
void	setSessionTimeout(long sessionTimeout)

Methods inherited from class org.apache.synapse.endpoints.LoadbalanceEndpoint

destroy, getAlgorithm, getMembers, getNextChild, isFailover, readyToSend, setAlgorithm, setFailover, setMembers, startApplicationMembershipTimer

Methods inherited from class org.apache.synapse.endpoints.AbstractEndpoint

addProperties, addProperty, evaluateProperties, getChildren, getContext, getDefinition, getDescription, getErrorHandler, getFileName, getMetricsMBean, getName, getParentEndpoint, getProperties, getProperty, handleException, handleException, informFailure, isAnonymous, isInitialized, isLeafEndpoint, isRetryDisabled, isSuspendFault, isTimeout, isTraceOn, isTraceOrDebugOn, logOnChildEndpointFail, onFault, onSuccess, prepareForEndpointStatistics, removeProperty, setAnonymous, setChildren, setDefinition, setDescription, setEnableMBeanStats, setErrorHandler, setErrorOnMessage, setFileName, setName, setParentEndpoint, toString, traceOrDebug

Methods inherited from class org.apache.synapse.FaultHandler

getStackTrace, handleFault, handleFault

Methods inherited from class java.lang.Object

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

Constructor Detail

SALoadbalanceEndpoint

public SALoadbalanceEndpoint()

Method Detail

init

public void init(SynapseEnvironment synapseEnvironment)

Description copied from interface: ManagedLifecycle

This method should implement the initialization of the implemented parts of the configuration.

Specified by:

init in interface ManagedLifecycle

Overrides:

init in class LoadbalanceEndpoint

Parameters:

synapseEnvironment - SynapseEnvironment to be used for initialization

send

public void send(MessageContext synCtx)

Description copied from interface: Endpoint

Sends the message context according to an endpoint specific behavior.

Specified by:

send in interface Endpoint

Overrides:

send in class LoadbalanceEndpoint

Parameters:

synCtx - MessageContext to be sent.

getDispatcher

public Dispatcher getDispatcher()

setDispatcher

public void setDispatcher(Dispatcher dispatcher)

onChildEndpointFail

public void onChildEndpointFail(Endpoint endpoint,
                                MessageContext synCtx)

It is logically incorrect to failover a session affinity endpoint after the session has started. If we redirect a message belonging to a particular session, new endpoint is not aware of the session. So we can't handle anything more at the endpoint level. Therefore, this method just deactivate the failed endpoint and give the fault to the next fault handler.

But if the session has not started (i.e. first message), the message will be resend by binding it to a different endpoint.

Specified by:

onChildEndpointFail in interface Endpoint

Overrides:

onChildEndpointFail in class LoadbalanceEndpoint

Parameters:

endpoint - Failed endpoint.

synCtx - MessageContext of the failed message.

getSessionTimeout

public long getSessionTimeout()

setSessionTimeout

public void setSessionTimeout(long sessionTimeout)