org.elasticsearch.common.logging.NodeAndClusterIdStateListener Maven / Gradle / Ivy
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package org.elasticsearch.common.logging;
import org.apache.logging.log4j.LogManager;
import org.apache.logging.log4j.Logger;
import org.elasticsearch.cluster.ClusterState;
import org.elasticsearch.cluster.ClusterStateObserver;
import org.elasticsearch.cluster.service.ClusterService;
import org.elasticsearch.common.unit.TimeValue;
import org.elasticsearch.common.util.concurrent.ThreadContext;
/**
* The {@link NodeAndClusterIdStateListener} listens to cluster state changes and ONLY when receives the first update
* it sets the clusterUUID and nodeID in log4j pattern converter {@link NodeAndClusterIdConverter}.
* Once the first update is received, it will automatically be de-registered from subsequent updates.
*/
public class NodeAndClusterIdStateListener implements ClusterStateObserver.Listener {
private static final Logger logger = LogManager.getLogger(NodeAndClusterIdStateListener.class);
private NodeAndClusterIdStateListener() {}
/**
* Subscribes for the first cluster state update where nodeId and clusterId is present
* and sets these values in {@link NodeAndClusterIdConverter}.
*/
public static void getAndSetNodeIdAndClusterId(ClusterService clusterService, ThreadContext threadContext) {
ClusterState clusterState = clusterService.state();
ClusterStateObserver observer = new ClusterStateObserver(clusterState, clusterService, null, logger, threadContext);
observer.waitForNextChange(new NodeAndClusterIdStateListener(), NodeAndClusterIdStateListener::isNodeAndClusterIdPresent);
}
private static boolean isNodeAndClusterIdPresent(ClusterState clusterState) {
return getNodeId(clusterState) != null && getClusterUUID(clusterState) != null;
}
private static String getClusterUUID(ClusterState state) {
return state.getMetaData().clusterUUID();
}
private static String getNodeId(ClusterState state) {
return state.getNodes().getLocalNodeId();
}
@Override
public void onNewClusterState(ClusterState state) {
String nodeId = getNodeId(state);
String clusterUUID = getClusterUUID(state);
logger.debug("Received cluster state update. Setting nodeId=[{}] and clusterUuid=[{}]", nodeId, clusterUUID);
NodeAndClusterIdConverter.setNodeIdAndClusterId(nodeId, clusterUUID);
}
@Override
public void onClusterServiceClose() {}
@Override
public void onTimeout(TimeValue timeout) {}
}