Package com.predic8.membrane.core.interceptor.balancer

Class LoadBalancingInterceptor

java.lang.Object

com.predic8.membrane.core.interceptor.AbstractInterceptor

com.predic8.membrane.core.interceptor.balancer.LoadBalancingInterceptor

All Implemented Interfaces:

Interceptor

public class LoadBalancingInterceptor
extends AbstractInterceptor

Description

Performs load-balancing between several nodes. Nodes sharing session state may be bundled into a cluster.

Explanation

May only be used as interceptor in a ServiceProxy.

Topic

7. Clustering and Loadbalancing

Nested Class Summary

Nested classes/interfaces inherited from interface com.predic8.membrane.core.interceptor.Interceptor

Interceptor.Flow

Field Summary

Fields inherited from class com.predic8.membrane.core.interceptor.AbstractInterceptor

name, router

Constructor Summary

Constructors

Constructor	Description
LoadBalancingInterceptor()

Method Summary

Modifier and Type	Method	Description
Balancer	getClusterManager()
List<Balancer>	getClustersFromSpring()
DispatchingStrategy	getDispatchingStrategy()
List<Node>	getEndpoints()
String	getName()	This is *NOT* AbstractInterceptor.getDisplayName(), but the balancer's name set in the proxy configuration to identify this balancer.
NodeOnlineChecker	getNodeOnlineChecker()
AbstractSessionIdExtractor	getSessionIdExtractor()
long	getSessionTimeout()
String	getShortDescription()
void	handleAbort(Exchange exc)	Called when any Interceptor.handleRequest(Exchange) or Interceptor.handleResponse(Exchange) later in the chain returned Outcome.ABORT or threw an exception.
Outcome	handleRequest(Exchange exc)
Outcome	handleResponse(Exchange exc)
void	init()	Called after parsing is complete and this has been added to the object tree (whose root is Router).
void	init(Router router)
boolean	isFailOver()
void	setClustersFromSpring(List<Balancer> balancers)
void	setDispatchingStrategy(DispatchingStrategy strategy)
void	setFailOver(boolean failOver)
void	setName(String name)	This is *NOT* AbstractInterceptor.setDisplayName(String), but the balancer's name set in the proxy configuration to identify this balancer.
void	setNodeOnlineChecker(NodeOnlineChecker noc)
void	setSessionIdExtractor(AbstractSessionIdExtractor sessionIdExtractor)
void	setSessionTimeout(long sessionTimeout)

Methods inherited from class com.predic8.membrane.core.interceptor.AbstractInterceptor

getDisplayName, getFlow, getHelpId, getLongDescription, getMessage, getRouter, getRule, setDisplayName, setFlow

Methods inherited from class java.lang.Object

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

Constructor Details

LoadBalancingInterceptor

public LoadBalancingInterceptor()

Method Details

init

public void init(Router router)
          throws Exception

Specified by:

init in interface Interceptor

Overrides:

init in class AbstractInterceptor

Throws:

Exception

handleRequest

public Outcome handleRequest(Exchange exc)
                      throws Exception

Specified by:

handleRequest in interface Interceptor

Overrides:

handleRequest in class AbstractInterceptor

Throws:

Exception

handleAbort

public void handleAbort(Exchange exc)

Description copied from interface: Interceptor

Called when any Interceptor.handleRequest(Exchange) or Interceptor.handleResponse(Exchange) later in the chain returned Outcome.ABORT or threw an exception.

handleAbort is called in the reverse order of the chain (as handleResponse is).

Specified by:

handleAbort in interface Interceptor

Overrides:

handleAbort in class AbstractInterceptor

handleResponse

public Outcome handleResponse(Exchange exc)
                       throws Exception

Specified by:

handleResponse in interface Interceptor

Overrides:

handleResponse in class AbstractInterceptor

Throws:

Exception

setName

public void setName(String name)
             throws Exception

This is *NOT* AbstractInterceptor.setDisplayName(String), but the balancer's name set in the proxy configuration to identify this balancer.

Throws:

Exception

Default

Default

Description

Uniquely identifies this Load Balancer, if there is more than one. Used in the web administration interface and lbclient to manage nodes.

Example

balancer1

getName

public String getName()

This is *NOT* AbstractInterceptor.getDisplayName(), but the balancer's name set in the proxy configuration to identify this balancer.

getDispatchingStrategy

public DispatchingStrategy getDispatchingStrategy()

setDispatchingStrategy

public void setDispatchingStrategy(DispatchingStrategy strategy)

Description

Sets the strategy used to choose the backend nodes.

getEndpoints

public List<Node> getEndpoints()

getSessionIdExtractor

public AbstractSessionIdExtractor getSessionIdExtractor()

setNodeOnlineChecker

public void setNodeOnlineChecker(NodeOnlineChecker noc)

Description

Checks if nodes are still available. Sets them to "DOWN" when not reachable, else sets them back up when they are reachable.

getNodeOnlineChecker

public NodeOnlineChecker getNodeOnlineChecker()

setSessionIdExtractor

public void setSessionIdExtractor(AbstractSessionIdExtractor sessionIdExtractor)

Description

Sets the strategy used to extract a session ID from incoming HTTP requests.

isFailOver

public boolean isFailOver()

setFailOver

public void setFailOver(boolean failOver)

getClusterManager

public Balancer getClusterManager()

setClustersFromSpring

public void setClustersFromSpring(List<Balancer> balancers)

Description

Specifies a list of clusters.

getClustersFromSpring

public List<Balancer> getClustersFromSpring()

getSessionTimeout

public long getSessionTimeout()

setSessionTimeout

public void setSessionTimeout(long sessionTimeout)

Default

3600000

Description

Time in milliseconds after which sessions time out. (If a session extractor is used.) Default is 1 hour, 0 means never.

Example

600000 (10min)

getShortDescription

public String getShortDescription()

Specified by:

getShortDescription in interface Interceptor

Overrides:

getShortDescription in class AbstractInterceptor

init

public void init()
          throws Exception

Description copied from class: AbstractInterceptor

Called after parsing is complete and this has been added to the object tree (whose root is Router).

Overrides:

init in class AbstractInterceptor

Throws:

Exception