org.apache.solr.common.cloud.Replica Maven / Gradle / Ivy
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* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under 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 "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.solr.common.cloud;
import java.util.Locale;
import java.util.Map;
import java.util.Set;
import org.noggit.JSONUtil;
import static org.apache.solr.common.cloud.ZkStateReader.BASE_URL_PROP;
import static org.apache.solr.common.cloud.ZkStateReader.CORE_NAME_PROP;
public class Replica extends ZkNodeProps {
/**
* The replica's state. In general, if the node the replica is hosted on is
* not under {@code /live_nodes} in ZK, the replica's state should be
* discarded.
*/
public enum State {
/**
* The replica is ready to receive updates and queries.
*
* NOTE: when the node the replica is hosted on crashes, the
* replica's state may remain ACTIVE in ZK. To determine if the replica is
* truly active, you must also verify that its {@link Replica#getNodeName()
* node} is under {@code /live_nodes} in ZK (or use
* {@link ClusterState#liveNodesContain(String)}).
*
*/
ACTIVE,
/**
* The first state before {@link State#RECOVERING}. A node in this state
* should be actively trying to move to {@link State#RECOVERING}.
*
* NOTE: a replica's state may appear DOWN in ZK also when the node
* it's hosted on gracefully shuts down. This is a best effort though, and
* should not be relied on.
*
*/
DOWN,
/**
* The node is recovering from the leader. This might involve peer-sync,
* full replication or finding out things are already in sync.
*/
RECOVERING,
/**
* Recovery attempts have not worked, something is not right.
*
* NOTE: This state doesn't matter if the node is not part of
* {@code /live_nodes} in ZK; in that case the node is not part of the
* cluster and it's state should be discarded.
*
*/
RECOVERY_FAILED;
@Override
public String toString() {
return super.toString().toLowerCase(Locale.ROOT);
}
/** Converts the state string to a State instance. */
public static State getState(String stateStr) {
return stateStr == null ? null : State.valueOf(stateStr.toUpperCase(Locale.ROOT));
}
}
private final String name;
private final String nodeName;
private final State state;
public Replica(String name, Map propMap) {
super(propMap);
this.name = name;
this.nodeName = (String) propMap.get(ZkStateReader.NODE_NAME_PROP);
if (propMap.get(ZkStateReader.STATE_PROP) != null) {
this.state = State.getState((String) propMap.get(ZkStateReader.STATE_PROP));
} else {
this.state = State.ACTIVE; //Default to ACTIVE
propMap.put(ZkStateReader.STATE_PROP, state.toString());
}
}
public String getName() {
return name;
}
public String getCoreUrl() {
return ZkCoreNodeProps.getCoreUrl(getStr(BASE_URL_PROP), getStr(CORE_NAME_PROP));
}
public String getCoreName() {
return getStr(CORE_NAME_PROP);
}
/** The name of the node this replica resides on */
public String getNodeName() {
return nodeName;
}
/** Returns the {@link State} of this replica. */
public State getState() {
return state;
}
public boolean isActive(Set liveNodes) {
return liveNodes.contains(this.nodeName) && this.state == State.ACTIVE;
}
@Override
public String toString() {
return name + ':' + JSONUtil.toJSON(propMap, -1); // small enough, keep it on one line (i.e. no indent)
}
}