org.elasticsearch.discovery.Discovery Maven / Gradle / Ivy
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* the Apache License, Version 2.0 (the "License"); you may
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*
* http://www.apache.org/licenses/LICENSE-2.0
*
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package org.elasticsearch.discovery;
import org.elasticsearch.cluster.ClusterState;
import org.elasticsearch.cluster.block.ClusterBlock;
import org.elasticsearch.cluster.block.ClusterBlockLevel;
import org.elasticsearch.cluster.node.DiscoveryNode;
import org.elasticsearch.cluster.routing.allocation.AllocationService;
import org.elasticsearch.common.Nullable;
import org.elasticsearch.common.component.LifecycleComponent;
import org.elasticsearch.node.service.NodeService;
import org.elasticsearch.rest.RestStatus;
/**
* A pluggable module allowing to implement discovery of other nodes, publishing of the cluster
* state to all nodes, electing a master of the cluster that raises cluster state change
* events.
*/
public interface Discovery extends LifecycleComponent {
final ClusterBlock NO_MASTER_BLOCK = new ClusterBlock(2, "no master", true, true, RestStatus.SERVICE_UNAVAILABLE, ClusterBlockLevel.ALL);
DiscoveryNode localNode();
void addListener(InitialStateDiscoveryListener listener);
void removeListener(InitialStateDiscoveryListener listener);
String nodeDescription();
/**
* Here as a hack to solve dep injection problem...
*/
void setNodeService(@Nullable NodeService nodeService);
/**
* Another hack to solve dep injection problem..., note, this will be called before
* any start is called.
*/
void setAllocationService(AllocationService allocationService);
/**
* Publish all the changes to the cluster from the master (can be called just by the master). The publish
* process should not publish this state to the master as well! (the master is sending it...).
*
* The {@link AckListener} allows to keep track of the ack received from nodes, and verify whether
* they updated their own cluster state or not.
*/
void publish(ClusterState clusterState, AckListener ackListener);
public static interface AckListener {
void onNodeAck(DiscoveryNode node, @Nullable Throwable t);
void onTimeout();
}
}