bbeaudreault commented on code in PR #5275: URL: https://github.com/apache/hbase/pull/5275#discussion_r1240875045
########## 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: Correct me if I'm wrong, but in the context of AsyncScanSingleRegionRpcRetryingCaller, `remainingTimeNs()` is only called once prior to this patch. The call moved into our new PauseManager code, so I assume that method is now unused. In the context of AsyncBatchRpcRetryingCaller, it is called 3 times... so not unused at this point, but maybe could still be unified. I feel like we could do this: 1. Remove `startNs` arg from PauseManager constructor, since as you said it's not final for scans. 2. expose `PauseManager.remainingTimeNs()` as public or package protected, and add a `long startNs` argument. 3. Also add `long startNs` as argument in `getPauseNsFromException()` since it seems we need that for scans 4. In getPauseNsFromException(), use `remainingTimeNs(startNs) - SLEEP_DELTA_NS` (so the SLEEP_DELTA_NS gets removed from `PauseManager.remainingTimeNs(long startNs)` method 5. Replace all the calls to existing `remainingTimeNs()` methods in AsyncBatchCaller with `pauseManager.remainingTimeNs(startNs)` Thoughts? -- This is an automated message from the Apache Git Service. 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