kafka.server.BrokerStates.scala 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 kafka.server
/**
* Broker states are the possible state that a kafka broker can be in.
* A broker should be only in one state at a time.
* The expected state transition with the following defined states is:
*
* +-----------+
* |Not Running|
* +-----+-----+
* |
* v
* +-----+-----+
* |Starting +--+
* +-----+-----+ | +----+------------+
* | +>+RecoveringFrom |
* v |UncleanShutdown |
* +----------+ +-----+-----+ +-------+---------+
* |RunningAs | |RunningAs | |
* |Controller+<--->+Broker +<-----------+
* +----------+ +-----+-----+
* | |
* | v
* | +-----+------------+
* |-----> |PendingControlled |
* |Shutdown |
* +-----+------------+
* |
* v
* +-----+----------+
* |BrokerShutting |
* |Down |
* +-----+----------+
* |
* v
* +-----+-----+
* |Not Running|
* +-----------+
*
* Custom states is also allowed for cases where there are custom kafka states for different scenarios.
*/
sealed trait BrokerStates { def state: Byte }
case object NotRunning extends BrokerStates { val state: Byte = 0 }
case object Starting extends BrokerStates { val state: Byte = 1 }
case object RecoveringFromUncleanShutdown extends BrokerStates { val state: Byte = 2 }
case object RunningAsBroker extends BrokerStates { val state: Byte = 3 }
case object RunningAsController extends BrokerStates { val state: Byte = 4 }
case object PendingControlledShutdown extends BrokerStates { val state: Byte = 6 }
case object BrokerShuttingDown extends BrokerStates { val state: Byte = 7 }
case class BrokerState() {
@volatile var currentState: Byte = NotRunning.state
def newState(newState: BrokerStates) {
this.newState(newState.state)
}
// Allowing undefined custom state
def newState(newState: Byte) {
currentState = newState
}
}