diff --git a/hadoop-common-project/hadoop-common/CHANGES.txt b/hadoop-common-project/hadoop-common/CHANGES.txt index 56edcacdba..d6d43f29dd 100644 --- a/hadoop-common-project/hadoop-common/CHANGES.txt +++ b/hadoop-common-project/hadoop-common/CHANGES.txt @@ -725,6 +725,8 @@ Release 2.8.0 - UNRELEASED HADOOP-12189. Improve CallQueueManager#swapQueue to make queue elements drop nearly impossible. (Zhihai Xu via wang) + HADOOP-12259. Utility to Dynamic port allocation (brahmareddy via rkanter) + OPTIMIZATIONS HADOOP-11785. Reduce the number of listStatus operation in distcp diff --git a/hadoop-common-project/hadoop-common/src/test/java/org/apache/hadoop/net/ServerSocketUtil.java b/hadoop-common-project/hadoop-common/src/test/java/org/apache/hadoop/net/ServerSocketUtil.java new file mode 100644 index 0000000000..0ce835f225 --- /dev/null +++ b/hadoop-common-project/hadoop-common/src/test/java/org/apache/hadoop/net/ServerSocketUtil.java @@ -0,0 +1,63 @@ +/** + * 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.net; + +import java.io.IOException; +import java.net.ServerSocket; +import java.util.Random; + +import org.apache.commons.logging.Log; +import org.apache.commons.logging.LogFactory; + +public class ServerSocketUtil { + + private static final Log LOG = LogFactory.getLog(ServerSocketUtil.class); + + /** + * Port scan & allocate is how most other apps find ports + * + * @param port given port + * @param retries number of retires + * @return + * @throws IOException + */ + public static int getPort(int port, int retries) throws IOException { + Random rand = new Random(); + int tryPort = port; + int tries = 0; + while (true) { + if (tries > 0) { + tryPort = port + rand.nextInt(65535 - port); + } + LOG.info("Using port " + tryPort); + try (ServerSocket s = new ServerSocket(tryPort)) { + return tryPort; + } catch (IOException e) { + tries++; + if (tries >= retries) { + LOG.info("Port is already in use; giving up"); + throw e; + } else { + LOG.info("Port is already in use; trying again"); + } + } + } + } + +}