Java tutorial
/** * 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.tracing; import java.io.ByteArrayOutputStream; import java.io.IOException; import java.io.PrintStream; import java.net.InetSocketAddress; import java.util.Arrays; import java.util.LinkedList; import java.util.List; import org.apache.commons.io.Charsets; import org.apache.hadoop.classification.InterfaceAudience; import org.apache.hadoop.conf.Configuration; import org.apache.hadoop.conf.Configured; import org.apache.hadoop.ipc.ProtobufRpcEngine; import org.apache.hadoop.ipc.RPC; import org.apache.hadoop.net.NetUtils; import org.apache.hadoop.security.UserGroupInformation; import org.apache.hadoop.tools.TableListing; import org.apache.hadoop.util.StringUtils; import org.apache.hadoop.util.Tool; /** * A command-line tool for viewing and modifying tracing settings. */ @InterfaceAudience.Private public class TraceAdmin extends Configured implements Tool { private TraceAdminProtocolPB proxy; private TraceAdminProtocolTranslatorPB remote; private void usage() { PrintStream err = System.err; err.print("Hadoop tracing configuration commands:\n" + " -add [-class classname] [-Ckey=value] [-Ckey2=value2] ...\n" + " Add a span receiver with the provided class name. Configuration\n" + " keys for the span receiver can be specified with the -C options.\n" + " The span receiver will also inherit whatever configuration keys\n" + " exist in the daemon's configuration.\n" + " -help: Print this help message.\n" + " -host [hostname:port]\n" + " Specify the hostname and port of the daemon to examine.\n" + " Required for all commands.\n" + " -list: List the current span receivers.\n" + " -remove [id]\n" + " Remove the span receiver with the specified id. Use -list to\n" + " find the id of each receiver.\n"); } private int listSpanReceivers(List<String> args) throws IOException { SpanReceiverInfo infos[] = remote.listSpanReceivers(); if (infos.length == 0) { System.out.println("[no span receivers found]"); return 0; } TableListing listing = new TableListing.Builder().addField("ID").addField("CLASS").showHeaders().build(); for (SpanReceiverInfo info : infos) { listing.addRow("" + info.getId(), info.getClassName()); } System.out.println(listing.toString()); return 0; } private final static String CONFIG_PREFIX = "-C"; private int addSpanReceiver(List<String> args) throws IOException { String className = StringUtils.popOptionWithArgument("-class", args); if (className == null) { System.err.println("You must specify the classname with -class."); return 1; } ByteArrayOutputStream configStream = new ByteArrayOutputStream(); PrintStream configsOut = new PrintStream(configStream, false, "UTF-8"); SpanReceiverInfoBuilder factory = new SpanReceiverInfoBuilder(className); String prefix = ""; for (int i = 0; i < args.size(); ++i) { String str = args.get(i); if (!str.startsWith(CONFIG_PREFIX)) { System.err.println("Can't understand argument: " + str); return 1; } str = str.substring(CONFIG_PREFIX.length()); int equalsIndex = str.indexOf("="); if (equalsIndex < 0) { System.err.println("Can't parse configuration argument " + str); System.err.println("Arguments must be in the form key=value"); return 1; } String key = str.substring(0, equalsIndex); String value = str.substring(equalsIndex + 1); factory.addConfigurationPair(key, value); configsOut.print(prefix + key + " = " + value); prefix = ", "; } String configStreamStr = configStream.toString("UTF-8"); try { long id = remote.addSpanReceiver(factory.build()); System.out.println("Added trace span receiver " + id + " with configuration " + configStreamStr); } catch (IOException e) { System.out.println("addSpanReceiver error with configuration " + configStreamStr); throw e; } return 0; } private int removeSpanReceiver(List<String> args) throws IOException { String indexStr = StringUtils.popFirstNonOption(args); long id = -1; try { id = Long.parseLong(indexStr); } catch (NumberFormatException e) { System.err.println("Failed to parse ID string " + indexStr + ": " + e.getMessage()); return 1; } remote.removeSpanReceiver(id); System.err.println("Removed trace span receiver " + id); return 0; } @Override public int run(String argv[]) throws Exception { LinkedList<String> args = new LinkedList<String>(); for (String arg : argv) { args.add(arg); } if (StringUtils.popOption("-h", args) || StringUtils.popOption("-help", args)) { usage(); return 0; } else if (args.size() == 0) { usage(); return 0; } String hostPort = StringUtils.popOptionWithArgument("-host", args); if (hostPort == null) { System.err.println("You must specify a host with -host."); return 1; } if (args.size() < 0) { System.err.println("You must specify an operation."); return 1; } RPC.setProtocolEngine(getConf(), TraceAdminProtocolPB.class, ProtobufRpcEngine.class); InetSocketAddress address = NetUtils.createSocketAddr(hostPort); UserGroupInformation ugi = UserGroupInformation.getCurrentUser(); Class<?> xface = TraceAdminProtocolPB.class; proxy = (TraceAdminProtocolPB) RPC.getProxy(xface, RPC.getProtocolVersion(xface), address, ugi, getConf(), NetUtils.getDefaultSocketFactory(getConf()), 0); remote = new TraceAdminProtocolTranslatorPB(proxy); try { if (args.get(0).equals("-list")) { return listSpanReceivers(args.subList(1, args.size())); } else if (args.get(0).equals("-add")) { return addSpanReceiver(args.subList(1, args.size())); } else if (args.get(0).equals("-remove")) { return removeSpanReceiver(args.subList(1, args.size())); } else { System.err.println("Unrecognized tracing command: " + args.get(0)); System.err.println("Use -help for help."); return 1; } } finally { remote.close(); } } public static void main(String[] argv) throws Exception { TraceAdmin admin = new TraceAdmin(); admin.setConf(new Configuration()); System.exit(admin.run(argv)); } }