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ASF GitHub Bot commented on FLINK-3190: --------------------------------------- Github user fijolekProjects commented on a diff in the pull request: https://github.com/apache/flink/pull/1954#discussion_r69491844 --- Diff: flink-runtime/src/main/java/org/apache/flink/runtime/executiongraph/restart/FailureRateRestartStrategy.java --- @@ -0,0 +1,108 @@ +/* + * 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.flink.runtime.executiongraph.restart; + +import com.google.common.base.Preconditions; +import org.apache.flink.configuration.ConfigConstants; +import org.apache.flink.configuration.Configuration; +import org.apache.flink.runtime.executiongraph.ExecutionGraph; +import scala.concurrent.duration.Duration; + +import java.util.ArrayList; +import java.util.List; +import java.util.concurrent.TimeUnit; + +import static akka.dispatch.Futures.future; + +/** + * Restart strategy which tries to restart the given {@link ExecutionGraph} when failure rate exceeded + * with a fixed time delay in between. + */ +public class FailureRateRestartStrategy implements RestartStrategy { + private final int maxFailuresPerUnit; + private final TimeUnit failureRateUnit; + private final long delayBetweenRestartAttempts; + private List<Long> restartTimestamps = new ArrayList<>(); + private boolean disabled = false; + + public FailureRateRestartStrategy(int maxFailuresPerUnit, TimeUnit failureRateUnit, long delayBetweenRestartAttempts) { + Preconditions.checkArgument(maxFailuresPerUnit > 0, "Maximum number of restart attempts per time unit must be greater than 0."); + Preconditions.checkArgument(delayBetweenRestartAttempts >= 0, "Delay between restart attempts must be positive"); + + this.maxFailuresPerUnit = maxFailuresPerUnit; + this.failureRateUnit = failureRateUnit; + this.delayBetweenRestartAttempts = delayBetweenRestartAttempts; + } + + @Override + public boolean canRestart() { + return !disabled && canRestartJob(); + } + + private boolean canRestartJob() { + int restartsInWindowSoFar = restartTimestamps.size(); + if (restartsInWindowSoFar >= maxFailuresPerUnit) { + List<Long> lastFailures = restartTimestamps.subList(restartsInWindowSoFar - maxFailuresPerUnit, restartsInWindowSoFar); + restartTimestamps = lastFailures; //deallocating not needed timestamps --- End diff -- Great catch. After all I used EvictingQueue<Long> it looks really fine for this task > Retry rate limits for DataStream API > ------------------------------------ > > Key: FLINK-3190 > URL: https://issues.apache.org/jira/browse/FLINK-3190 > Project: Flink > Issue Type: Improvement > Reporter: Sebastian Klemke > Assignee: Michał Fijołek > Priority: Minor > > For a long running stream processing job, absolute numbers of retries don't > make much sense: The job will accumulate transient errors over time and will > die eventually when thresholds are exceeded. Rate limits are better suited in > this scenario: A job should only die, if it fails too often in a given time > frame. To better overcome transient errors, retry delays could be used, as > suggested in other issues. > Absolute numbers of retries can still make sense, if failing operators don't > make any progress at all. We can measure progress by OperatorState changes > and by observing output, as long as the operator in question is not a sink. > If operator state changes and/or operator produces output, we can assume it > makes progress. > As an example, let's say we configured a retry rate limit of 10 retries per > hour and a non-sink operator A. If the operator fails once every 10 minutes > and produces output between failures, it should not lead to job termination. > But if the operator fails 11 times in an hour or does not produce output > between 11 consecutive failures, job should be terminated. -- This message was sent by Atlassian JIRA (v6.3.4#6332)