ajfabbri commented on code in PR #8426: URL: https://github.com/apache/hadoop/pull/8426#discussion_r3438839505
########## hadoop-tools/hadoop-aws/src/test/java/org/apache/hadoop/fs/s3a/ITestS3ASharedThreadPoolDisabled.java: ########## @@ -0,0 +1,74 @@ +/* + * 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.fs.s3a; + +import org.assertj.core.api.Assertions; +import org.junit.jupiter.api.Test; +import org.slf4j.Logger; +import org.slf4j.LoggerFactory; + +/** + * Control case for {@link ITestS3ASharedThreadPoolEnabled}: with the shared + * pool disabled (the default), each S3AFileSystem's AWS SDK clients create their + * own sdk-ScheduledExecutor pool, so thread count grows with the number of + * instances. Kept a separate class so it runs in its own JVM (hadoop-aws uses + * reuseForks=false) and the static holders never memoize in the enabled state. Review Comment: Thanks for the detailed comment here. I've been playing with test parallelization in my spare time (for faster CI) and these sorts of comments help a lot with figuring out why tests become flaky when we stop giving each test class a fresh JVM. (Side note: it would be nice if we could express this with annotations like Junit5 [ExecutionMode](https://docs.junit.org/5.3.0/api/org/junit/jupiter/api/parallel/ExecutionMode.html) in the future and then choose more aggressive parallelism / JVM reuse.) -- 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]
