org.apache.kafka.common.network.ChannelState Maven / Gradle / Ivy
/*
* 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.kafka.common.network;
import org.apache.kafka.common.errors.AuthenticationException;
/**
* States for KafkaChannel:
*
* - NOT_CONNECTED: Connections are created in NOT_CONNECTED state. State is updated
* on {@link TransportLayer#finishConnect()} when socket connection is established.
* PLAINTEXT channels transition from NOT_CONNECTED to READY, others transition
* to AUTHENTICATE. Failures in NOT_CONNECTED state typically indicate that the
* remote endpoint is unavailable, which may be due to misconfigured endpoints.
* - AUTHENTICATE: SSL, SASL_SSL and SASL_PLAINTEXT channels are in AUTHENTICATE state during SSL and
* SASL handshake. Disconnections in AUTHENTICATE state may indicate that authentication failed with
* SSL or SASL (broker version < 1.0.0). Channels transition to READY state when authentication completes
* successfully.
* - READY: Connected, authenticated channels are in READY state. Channels may transition from
* READY to EXPIRED, FAILED_SEND or LOCAL_CLOSE.
* - EXPIRED: Idle connections are moved to EXPIRED state on idle timeout and the channel is closed.
* - FAILED_SEND: Channels transition from READY to FAILED_SEND state if the channel is closed due
* to a send failure.
* - AUTHENTICATION_FAILED: Channels are moved to this state if the requested SASL mechanism is not
* enabled in the broker or when brokers with versions 1.0.0 and above provide an error response
* during SASL authentication. {@link #exception()} gives the reason provided by the broker for
* authentication failure.
* - LOCAL_CLOSE: Channels are moved to LOCAL_CLOSE state if close() is initiated locally.
*
* If the remote endpoint closes a channel, the state of the channel reflects the state the channel
* was in at the time of disconnection. This state may be useful to identify the reason for disconnection.
*
* Typical transitions:
*
* - PLAINTEXT Good path: NOT_CONNECTED => READY => LOCAL_CLOSE
* - SASL/SSL Good path: NOT_CONNECTED => AUTHENTICATE => READY => LOCAL_CLOSE
* - Bootstrap server misconfiguration: NOT_CONNECTED, disconnected in NOT_CONNECTED state
* - Security misconfiguration: NOT_CONNECTED => AUTHENTICATE => AUTHENTICATION_FAILED, disconnected in AUTHENTICATION_FAILED state
* - Security misconfiguration with older broker: NOT_CONNECTED => AUTHENTICATE, disconnected in AUTHENTICATE state
*
*/
public class ChannelState {
public enum State {
NOT_CONNECTED,
AUTHENTICATE,
READY,
EXPIRED,
FAILED_SEND,
AUTHENTICATION_FAILED,
LOCAL_CLOSE
}
// AUTHENTICATION_FAILED has a custom exception. For other states,
// create a reusable `ChannelState` instance per-state.
public static final ChannelState NOT_CONNECTED = new ChannelState(State.NOT_CONNECTED);
public static final ChannelState AUTHENTICATE = new ChannelState(State.AUTHENTICATE);
public static final ChannelState READY = new ChannelState(State.READY);
public static final ChannelState EXPIRED = new ChannelState(State.EXPIRED);
public static final ChannelState FAILED_SEND = new ChannelState(State.FAILED_SEND);
public static final ChannelState LOCAL_CLOSE = new ChannelState(State.LOCAL_CLOSE);
private final State state;
private final AuthenticationException exception;
private final String remoteAddress;
public ChannelState(State state) {
this(state, null, null);
}
public ChannelState(State state, String remoteAddress) {
this(state, null, remoteAddress);
}
public ChannelState(State state, AuthenticationException exception, String remoteAddress) {
this.state = state;
this.exception = exception;
this.remoteAddress = remoteAddress;
}
public State state() {
return state;
}
public AuthenticationException exception() {
return exception;
}
public String remoteAddress() {
return remoteAddress;
}
}