org.graylog.shaded.kafka09.kafka.server.KafkaHealthcheck.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
import kafka.cluster.EndPoint
import kafka.utils._
import org.apache.kafka.common.protocol.SecurityProtocol
import org.apache.zookeeper.Watcher.Event.KeeperState
import org.I0Itec.zkclient.{IZkStateListener, ZkClient, ZkConnection}
import java.net.InetAddress
/**
* This class registers the broker in zookeeper to allow
* other brokers and consumers to detect failures. It uses an ephemeral znode with the path:
* /brokers/[0...N] --> advertisedHost:advertisedPort
*
* Right now our definition of health is fairly naive. If we register in zk we are healthy, otherwise
* we are dead.
*/
class KafkaHealthcheck(private val brokerId: Int,
private val advertisedEndpoints: Map[SecurityProtocol, EndPoint],
private val zkUtils: ZkUtils) extends Logging {
val brokerIdPath = ZkUtils.BrokerIdsPath + "/" + brokerId
val sessionExpireListener = new SessionExpireListener
def startup() {
zkUtils.zkClient.subscribeStateChanges(sessionExpireListener)
register()
}
/**
* Register this broker as "alive" in zookeeper
*/
def register() {
val jmxPort = System.getProperty("com.sun.management.jmxremote.port", "-1").toInt
val updatedEndpoints = advertisedEndpoints.mapValues(endpoint =>
if (endpoint.host == null || endpoint.host.trim.isEmpty)
EndPoint(InetAddress.getLocalHost.getCanonicalHostName, endpoint.port, endpoint.protocolType)
else
endpoint
)
// the default host and port are here for compatibility with older client
// only PLAINTEXT is supported as default
// if the broker doesn't listen on PLAINTEXT protocol, an empty endpoint will be registered and older clients will be unable to connect
val plaintextEndpoint = updatedEndpoints.getOrElse(SecurityProtocol.PLAINTEXT, new EndPoint(null,-1,null))
zkUtils.registerBrokerInZk(brokerId, plaintextEndpoint.host, plaintextEndpoint.port, updatedEndpoints, jmxPort)
}
/**
* When we get a SessionExpired event, we lost all ephemeral nodes and zkclient has reestablished a
* connection for us. We need to re-register this broker in the broker registry.
*/
class SessionExpireListener() extends IZkStateListener {
@throws(classOf[Exception])
def handleStateChanged(state: KeeperState) {}
/**
* Called after the zookeeper session has expired and a new session has been created. You would have to re-create
* any ephemeral nodes here.
*
* @throws Exception
* On any error.
*/
@throws(classOf[Exception])
def handleNewSession() {
info("re-registering broker info in ZK for broker " + brokerId)
register()
info("done re-registering broker")
info("Subscribing to %s path to watch for new topics".format(ZkUtils.BrokerTopicsPath))
}
override def handleSessionEstablishmentError(error: Throwable): Unit = {
fatal("Could not establish session with zookeeper", error)
}
}
}