| /** |
| * |
| * 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; |
| |
| import java.io.IOException; |
| import java.lang.management.ManagementFactory; |
| |
| import org.apache.yetus.audience.InterfaceAudience; |
| import org.slf4j.Logger; |
| import org.slf4j.LoggerFactory; |
| import org.apache.hadoop.hbase.util.Addressing; |
| import org.apache.hadoop.hbase.util.Bytes; |
| |
| /** |
| * The class that is able to determine some unique strings for the client, |
| * such as an IP address, PID, and composite deterministic ID. |
| */ |
| @InterfaceAudience.Private |
| final class ClientIdGenerator { |
| private static final Logger LOG = LoggerFactory.getLogger(ClientIdGenerator.class); |
| |
| private ClientIdGenerator() {} |
| |
| /** |
| * @return a unique ID incorporating IP address, PID, TID and timer. Might be an overkill... |
| * Note though that new UUID in java by default is just a random number. |
| */ |
| public static byte[] generateClientId() { |
| byte[] selfBytes = getIpAddressBytes(); |
| Long pid = getPid(); |
| long tid = Thread.currentThread().getId(); |
| long ts = System.currentTimeMillis(); |
| |
| byte[] id = new byte[selfBytes.length + ((pid != null ? 1 : 0) + 2) * Bytes.SIZEOF_LONG]; |
| int offset = Bytes.putBytes(id, 0, selfBytes, 0, selfBytes.length); |
| if (pid != null) { |
| offset = Bytes.putLong(id, offset, pid); |
| } |
| offset = Bytes.putLong(id, offset, tid); |
| offset = Bytes.putLong(id, offset, ts); |
| assert offset == id.length; |
| return id; |
| } |
| |
| /** |
| * @return PID of the current process, if it can be extracted from JVM name, or null. |
| */ |
| public static Long getPid() { |
| String name = ManagementFactory.getRuntimeMXBean().getName(); |
| String[] nameParts = name.split("@"); |
| if (nameParts.length == 2) { // 12345@somewhere |
| try { |
| return Long.parseLong(nameParts[0]); |
| } catch (NumberFormatException ex) { |
| LOG.warn("Failed to get PID from [" + name + "]", ex); |
| } |
| } else { |
| LOG.warn("Don't know how to get PID from [" + name + "]"); |
| } |
| return null; |
| } |
| |
| /** |
| * @return Some IPv4/IPv6 address available on the current machine that is up, not virtual |
| * and not a loopback address. Empty array if none can be found or error occurred. |
| */ |
| public static byte[] getIpAddressBytes() { |
| try { |
| return Addressing.getIpAddress().getAddress(); |
| } catch (IOException ex) { |
| LOG.warn("Failed to get IP address bytes", ex); |
| } |
| return new byte[0]; |
| } |
| } |