rmdmattingly commented on code in PR #5275: URL: https://github.com/apache/hbase/pull/5275#discussion_r1240863843
########## hbase-client/src/main/java/org/apache/hadoop/hbase/client/backoff/HBaseServerExceptionPauseManager.java: ########## @@ -0,0 +1,95 @@ +/* + * 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.hbase.client.backoff; + +import static org.apache.hadoop.hbase.client.ConnectionUtils.SLEEP_DELTA_NS; +import static org.apache.hadoop.hbase.client.ConnectionUtils.getPauseTime; + +import java.util.OptionalLong; +import java.util.concurrent.TimeUnit; +import org.apache.hadoop.hbase.HBaseServerException; +import org.apache.hadoop.hbase.quotas.RpcThrottlingException; +import org.apache.yetus.audience.InterfaceAudience; +import org.slf4j.Logger; +import org.slf4j.LoggerFactory; + [email protected] +public class HBaseServerExceptionPauseManager { + private static final Logger LOG = LoggerFactory.getLogger(HBaseServerExceptionPauseManager.class); + + private final long pauseNs; + private final long pauseNsForServerOverloaded; + private final long timeoutNs; + private final long startNs; + + public HBaseServerExceptionPauseManager(long pauseNs, long pauseNsForServerOverloaded, + long timeoutNs, long startNs) { + this.pauseNs = pauseNs; + this.pauseNsForServerOverloaded = pauseNsForServerOverloaded; + this.timeoutNs = timeoutNs; + this.startNs = startNs; + } + + /** + * Returns the nanos, if any, for which the client should wait + * @param error The exception from the server + * @param tries The current retry count + * @return The time, in nanos, to pause. If empty then pausing would exceed our timeout, so we + * should throw now + */ + public OptionalLong getPauseNsFromException(Throwable error, int tries) { + long expectedSleepNs; + if (error instanceof RpcThrottlingException) { + RpcThrottlingException rpcThrottlingException = (RpcThrottlingException) error; + expectedSleepNs = TimeUnit.MILLISECONDS.toNanos(rpcThrottlingException.getWaitInterval()); + long remainingTimeNs = remainingTimeNs(); + if (expectedSleepNs > remainingTimeNs && remainingTimeNs > 0) { + if (LOG.isDebugEnabled()) { + LOG.debug("RpcThrottlingException suggested pause of {}ns which would exceed " + + "the timeout. We should throw instead.", expectedSleepNs, rpcThrottlingException); + } + return OptionalLong.empty(); + } + if (LOG.isDebugEnabled()) { + LOG.debug("Sleeping for {}ns after catching RpcThrottlingException", expectedSleepNs, + rpcThrottlingException); + } + } else { + expectedSleepNs = + HBaseServerException.isServerOverloaded(error) ? pauseNsForServerOverloaded : pauseNs; + // RpcThrottlingException tells us exactly how long the client should wait for, + // so we should not factor in the retry count for said exception + expectedSleepNs = getPauseTime(expectedSleepNs, tries - 1); + } + + if (timeoutNs > 0) { + long remainingTimeNs = remainingTimeNs(); + if (remainingTimeNs <= 0) { + return OptionalLong.empty(); + } + expectedSleepNs = Math.min(remainingTimeNs, expectedSleepNs); + } + + return OptionalLong.of(expectedSleepNs); + } + + private long remainingTimeNs() { Review Comment: Ah actually, I'm realizing this gets a little bit awkward too because the scanner's startNs obviously isn't final. So we either need to support mutability of that field in the pause manager, reconstruct the pause manager on each call, or continue to leave the timeout responsibility outside of the pause manager. Do you have a preference? Depending on the answer here we can certainly remove some of these remainingTimeNs methods -- 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]
