/*
* 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.nifi.cluster.coordination.node;
import javax.xml.bind.annotation.XmlEnum;
@XmlEnum(String.class)
public enum NodeConnectionState {
/**
* A node has issued a connection request to the cluster, but has not yet
* sent a heartbeat. A connecting node can transition to DISCONNECTED or CONNECTED. The cluster
* will not accept any external requests to change the flow while any node is in
* this state.
*/
CONNECTING,
/**
* A node that is connected to the cluster. A connecting node transitions
* to connected after the cluster receives the node's first heartbeat. A
* connected node can transition to disconnecting.
*/
CONNECTED,
/**
* A node that is in the process of disconnecting from the cluster.
* A DISCONNECTING node will always transition to DISCONNECTED.
*/
DISCONNECTING,
/**
* A node that is not connected to the cluster.
* A DISCONNECTED node can transition to CONNECTING.
*/
DISCONNECTED,
/**
* A NodeConnectionState of REMOVED indicates that the node was removed from the cluster
* and is used in order to notify other nodes in the cluster.
*/
REMOVED;
}