peterxcli commented on code in PR #11418: URL: https://github.com/apache/ozone/pull/11418#discussion_r4369616571
########## hadoop-ozone/common/src/main/java/org/apache/hadoop/ozone/om/ha/GrpcOMFollowerReadFailoverProxyProvider.java: ########## @@ -0,0 +1,125 @@ +/* + * 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.hadoop.ozone.om.ha; + +import static org.apache.hadoop.ozone.om.ha.OMFailoverProxyProviderBase.getLeaderNotReadyException; +import static org.apache.hadoop.ozone.om.ha.OMFailoverProxyProviderBase.getNotLeaderException; +import static org.apache.hadoop.ozone.om.ha.OMFailoverProxyProviderBase.getReadException; +import static org.apache.hadoop.ozone.om.ha.OMFailoverProxyProviderBase.getReadIndexException; + +import io.grpc.StatusRuntimeException; +import java.io.IOException; +import org.apache.hadoop.ozone.om.helpers.ReadConsistency; +import org.apache.hadoop.ozone.om.protocolPB.GrpcOmTransport; +import org.apache.hadoop.ozone.om.protocolPB.OzoneManagerProtocolPB; +import org.apache.hadoop.ozone.protocol.proto.OzoneManagerProtocolProtos.OMRequest; +import org.apache.hadoop.ozone.protocol.proto.OzoneManagerProtocolProtos.OMResponse; +import org.apache.ratis.protocol.exceptions.ReadException; +import org.apache.ratis.protocol.exceptions.ReadIndexException; +import org.apache.ratis.util.function.CheckedBiFunction; +import org.apache.ratis.util.function.CheckedFunction; +import org.slf4j.Logger; +import org.slf4j.LoggerFactory; + +/** + * Follower read support for {@link GrpcOmTransport}. + * <p> + * If follower read is enabled, a read request is sent to the current follower read OM node, + * which can be either a leader or a follower. If the OM node fails, the request is sent + * to the next OM node. If all the OM nodes have failed, the request falls back to the leader OM. + * <p> + * Write requests, and read requests when follower read is disabled, are sent to the leader OM. + */ +public class GrpcOMFollowerReadFailoverProxyProvider extends FollowerReadFailoverProxyProviderBase { + private static final Logger LOG = LoggerFactory.getLogger(GrpcOMFollowerReadFailoverProxyProvider.class); + + /** The inner proxy provider used for leader-based failover. */ + private final GrpcOMFailoverProxyProvider<OzoneManagerProtocolPB> leaderProxy; + + public GrpcOMFollowerReadFailoverProxyProvider(GrpcOMFailoverProxyProvider<OzoneManagerProtocolPB> leaderProxy, + ReadConsistency followerReadConsistencyType, ReadConsistency leaderReadConsistencyType, + boolean defaultFollowerReadEnabled) { + super(followerReadConsistencyType, leaderReadConsistencyType, defaultFollowerReadEnabled); + this.leaderProxy = leaderProxy; + } + + @Override + protected GrpcOMFailoverProxyProvider<OzoneManagerProtocolPB> getLeaderProxy() { + return leaderProxy; + } + + /** + * Submit the request to an OM follower if follower read is used, otherwise to the leader OM. + * + * @param payload the request to submit. + * @param submitToHost submits a request to the OM at the given gRPC address. + * @param submitToLeader submits a request to the leader OM, failing over between the OMs if needed. + * @return the response of the request. + */ + public OMResponse submitRequest(OMRequest payload, + CheckedBiFunction<OMRequest, String, OMResponse, IOException> submitToHost, + CheckedFunction<OMRequest, OMResponse, IOException> submitToLeader) throws IOException { + if (shouldUseFollowerRead(payload)) { + OMRequest followerPayload = addReadConsistencyHint(payload, true); + ReadConsistency readConsistency = getReadConsistency(payload); + int failedCount = 0; + for (int i = 0; i < getOMNodeCount(); i++) { + String nodeId = selectFollowerReadNodeId(readConsistency); + if (nodeId == null) { + break; + } + String followerHost = leaderProxy.getGrpcProxyAddress(nodeId); + try { + OMResponse response = submitToHost.apply(followerPayload, followerHost); + LOG.debug("Invocation with cmdType {} using follower read host {} was successful", + followerPayload.getCmdType(), followerHost); + return response; + } catch (StatusRuntimeException e) { + LOG.debug("Invocation with cmdType {} using follower read host {} failed", + followerPayload.getCmdType(), followerHost, e); + Exception unwrapped = GrpcOmTransport.unwrapException(new Exception(e)); + if (getNotLeaderException(unwrapped) != null) { + LOG.debug("Encountered OMNotLeaderException from {}. " + + "Disable OM follower read and retry OM leader directly.", followerHost); + disableFollowerRead(); + break; + } + if (getLeaderNotReadyException(unwrapped) != null) { Review Comment: https://issues.apache.org/jira/browse/HDDS-17448 -- 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. To unsubscribe, e-mail: [email protected] For queries about this service, please contact Infrastructure at: [email protected] --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
