org.elasticsearch.cluster.MasterNodeChangePredicate Maven / Gradle / Ivy
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* the Apache License, Version 2.0 (the "License"); you may
* not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing,
* software distributed under the License is distributed on an
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package org.elasticsearch.cluster;
import org.elasticsearch.cluster.node.DiscoveryNode;
import java.util.function.Predicate;
public final class MasterNodeChangePredicate {
private MasterNodeChangePredicate() {
}
/**
* builds a predicate that will accept a cluster state only if it was generated after the current has
* (re-)joined the master
*/
public static Predicate build(ClusterState currentState) {
final long currentVersion = currentState.version();
final DiscoveryNode masterNode = currentState.nodes().getMasterNode();
final String currentMasterId = masterNode == null ? null : masterNode.getEphemeralId();
return newState -> {
final DiscoveryNode newMaster = newState.nodes().getMasterNode();
final boolean accept;
if (newMaster == null) {
accept = false;
} else if (newMaster.getEphemeralId().equals(currentMasterId) == false) {
accept = true;
} else {
accept = newState.version() > currentVersion;
}
return accept;
};
}
}