Package com.couchbase.client.core.node

Class RoundRobinLocator

java.lang.Object

com.couchbase.client.core.node.RoundRobinLocator

All Implemented Interfaces:

Locator

Direct Known Subclasses:

AnalyticsLocator, ViewLocator

public class RoundRobinLocator
extends Object
implements Locator

A Locator which implements node selection on a round-robin basis.

This locator simply tracks a counter that gets incremented and applied to the list of nodes provided. The list of nodes is filtered to make sure that only nodes with the specific service are taken into account.

Since:

1.0.0

Constructor Summary

Constructors

Constructor	Description
RoundRobinLocator(ServiceType serviceType)

Method Summary

Modifier and Type	Method	Description
protected boolean	checkServiceNotAvailable(Request<? extends Response> request, ClusterConfig config)	Can be overridden to check if a request should be cancelled immediately that the service is not supported.
void	dispatch(Request<? extends Response> request, List<Node> nodes, ClusterConfig config, CoreContext ctx)	Given the environment and node information, the implementation locates the right set of nodes and dispatches the request into them.
protected boolean	nodeCanBeUsed(Node node, Request<? extends Response> request, ClusterConfig config)	This method can be overridden for additional per-node checks in addition to the service-type based check already performed in filterNodes(List, Request, ClusterConfig).

Methods inherited from class java.lang.Object

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

Constructor Details

RoundRobinLocator

public RoundRobinLocator(ServiceType serviceType)

Method Details

dispatch

public void dispatch(Request<? extends Response> request,
 List<Node> nodes,
 ClusterConfig config,
 CoreContext ctx)

Description copied from interface: Locator

Given the environment and node information, the implementation locates the right set of nodes and dispatches the request into them.

Specified by:

dispatch in interface Locator

Parameters:

request - the request to dispatch.

nodes - the current list of active nodes.

config - the current cluster configuration.

ctx - the core context.

checkServiceNotAvailable

protected boolean checkServiceNotAvailable(Request<? extends Response> request,
 ClusterConfig config)

Can be overridden to check if a request should be cancelled immediately that the service is not supported.

If this method returns false, something MUST be done with the request, or it will time out!

nodeCanBeUsed

protected boolean nodeCanBeUsed(Node node,
 Request<? extends Response> request,
 ClusterConfig config)

This method can be overridden for additional per-node checks in addition to the service-type based check already performed in filterNodes(List, Request, ClusterConfig).

This method will be called for each node in the list to find out if it can be used in principle for dispatching the request.

Parameters:

node - the node to check against.

request - the request in scope.

config - the cluster-level config.

Returns:

true if it can be used.