abbccdda commented on a change in pull request #9580: URL: https://github.com/apache/kafka/pull/9580#discussion_r520881459
########## File path: core/src/main/scala/kafka/server/ForwardingManager.scala ########## @@ -0,0 +1,85 @@ +/* + * 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.metrics.KafkaMetricsGroup +import kafka.network.RequestChannel +import org.apache.kafka.clients.ClientResponse +import org.apache.kafka.common.metrics.Metrics +import org.apache.kafka.common.protocol.Errors +import org.apache.kafka.common.requests.{AbstractRequest, AbstractResponse, EnvelopeRequest, EnvelopeResponse} +import org.apache.kafka.common.utils.Time + +import scala.compat.java8.OptionConverters._ + +class ForwardingManager(metadataCache: kafka.server.MetadataCache, + time: Time, + metrics: Metrics, + config: KafkaConfig, + threadNamePrefix: Option[String] = None) extends + BrokerToControllerChannelManagerImpl(metadataCache, time, metrics, + config, "forwardingChannel", threadNamePrefix) with KafkaMetricsGroup { + + private val forwardingMetricName = "NumRequestsForwardingToControllerPerSec" + + def forwardRequest(request: RequestChannel.Request, + responseCallback: AbstractResponse => Unit): Unit = { + val principalSerde = request.context.principalSerde.asScala.getOrElse( + throw new IllegalArgumentException(s"Cannot deserialize principal from request $request " + + "since there is no serde defined") + ) + val serializedPrincipal = principalSerde.serialize(request.context.principal) + val forwardRequestBuffer = request.buffer.duplicate() + forwardRequestBuffer.flip() + val envelopeRequest = new EnvelopeRequest.Builder( + forwardRequestBuffer, + serializedPrincipal, + request.context.clientAddress.getAddress + ) + + def onClientResponse(clientResponse: ClientResponse): Unit = { + val envelopeResponse = clientResponse.responseBody.asInstanceOf[EnvelopeResponse] + val envelopeError = envelopeResponse.error() + + val response = if (envelopeError != Errors.NONE) { + // An envelope error indicates broker misconfiguration (e.g. the principal serde + // might not be defined on the receiving broker). In this case, we do not return + // the error directly to the client since it would not be expected. Instead we + // return `UNKNOWN_SERVER_ERROR` so that the user knows that there is a problem + // on the broker. + debug(s"Forwarded request $request failed with an error in envelope response $envelopeError") + request.body[AbstractRequest].getErrorResponse(Errors.UNKNOWN_SERVER_ERROR.exception()) + } else { + AbstractResponse.deserializeBody(envelopeResponse.responseData, request.header) + } + responseCallback(response) + } + + sendRequest(envelopeRequest, onClientResponse) + } + + override def start(): Unit = { + super.start() + newGauge(forwardingMetricName, () => requestQueue.size()) + } + + override def shutdown(): Unit = { + super.shutdown() + removeMetric(forwardingMetricName) Review comment: Sg. ---------------------------------------------------------------- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. For queries about this service, please contact Infrastructure at: us...@infra.apache.org
