001/* 002 * GangliaContext.java 003 * 004 * Licensed to the Apache Software Foundation (ASF) under one 005 * or more contributor license agreements. See the NOTICE file 006 * distributed with this work for additional information 007 * regarding copyright ownership. The ASF licenses this file 008 * to you under the Apache License, Version 2.0 (the 009 * "License"); you may not use this file except in compliance 010 * with the License. You may obtain a copy of the License at 011 * 012 * http://www.apache.org/licenses/LICENSE-2.0 013 * 014 * Unless required by applicable law or agreed to in writing, software 015 * distributed under the License is distributed on an "AS IS" BASIS, 016 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 017 * See the License for the specific language governing permissions and 018 * limitations under the License. 019 */ 020 021package org.apache.hadoop.metrics.ganglia; 022 023import java.io.IOException; 024import java.net.DatagramPacket; 025import java.net.SocketAddress; 026import java.net.UnknownHostException; 027 028import org.apache.commons.logging.Log; 029import org.apache.commons.logging.LogFactory; 030import org.apache.hadoop.conf.Configuration; 031import org.apache.hadoop.metrics.ContextFactory; 032import org.apache.hadoop.net.DNS; 033 034/** 035 * Context for sending metrics to Ganglia version 3.1.x. 036 * 037 * 3.1.1 has a slightly different wire portal compared to 3.0.x. 038 */ 039public class GangliaContext31 extends GangliaContext { 040 041 String hostName = "UNKNOWN.example.com"; 042 043 private static final Log LOG = 044 LogFactory.getLog("org.apache.hadoop.util.GangliaContext31"); 045 046 public void init(String contextName, ContextFactory factory) { 047 super.init(contextName, factory); 048 049 LOG.debug("Initializing the GangliaContext31 for Ganglia 3.1 metrics."); 050 051 // Take the hostname from the DNS class. 052 053 Configuration conf = new Configuration(); 054 055 if (conf.get("slave.host.name") != null) { 056 hostName = conf.get("slave.host.name"); 057 } else { 058 try { 059 hostName = DNS.getDefaultHost( 060 conf.get("dfs.datanode.dns.interface","default"), 061 conf.get("dfs.datanode.dns.nameserver","default")); 062 } catch (UnknownHostException uhe) { 063 LOG.error(uhe); 064 hostName = "UNKNOWN.example.com"; 065 } 066 } 067 } 068 069 protected void emitMetric(String name, String type, String value) 070 throws IOException 071 { 072 if (name == null) { 073 LOG.warn("Metric was emitted with no name."); 074 return; 075 } else if (value == null) { 076 LOG.warn("Metric name " + name +" was emitted with a null value."); 077 return; 078 } else if (type == null) { 079 LOG.warn("Metric name " + name + ", value " + value + " has no type."); 080 return; 081 } 082 083 LOG.debug("Emitting metric " + name + ", type " + type + ", value " + 084 value + " from hostname" + hostName); 085 086 String units = getUnits(name); 087 int slope = getSlope(name); 088 int tmax = getTmax(name); 089 int dmax = getDmax(name); 090 offset = 0; 091 String groupName = name.substring(0,name.lastIndexOf(".")); 092 093 // The following XDR recipe was done through a careful reading of 094 // gm_protocol.x in Ganglia 3.1 and carefully examining the output of 095 // the gmetric utility with strace. 096 097 // First we send out a metadata message 098 xdr_int(128); // metric_id = metadata_msg 099 xdr_string(hostName); // hostname 100 xdr_string(name); // metric name 101 xdr_int(0); // spoof = False 102 xdr_string(type); // metric type 103 xdr_string(name); // metric name 104 xdr_string(units); // units 105 xdr_int(slope); // slope 106 xdr_int(tmax); // tmax, the maximum time between metrics 107 xdr_int(dmax); // dmax, the maximum data value 108 109 xdr_int(1); /*Num of the entries in extra_value field for 110 Ganglia 3.1.x*/ 111 xdr_string("GROUP"); /*Group attribute*/ 112 xdr_string(groupName); /*Group value*/ 113 114 for (SocketAddress socketAddress : metricsServers) { 115 DatagramPacket packet = 116 new DatagramPacket(buffer, offset, socketAddress); 117 datagramSocket.send(packet); 118 } 119 120 // Now we send out a message with the actual value. 121 // Technically, we only need to send out the metadata message once for 122 // each metric, but I don't want to have to record which metrics we did and 123 // did not send. 124 offset = 0; 125 xdr_int(133); // we are sending a string value 126 xdr_string(hostName); // hostName 127 xdr_string(name); // metric name 128 xdr_int(0); // spoof = False 129 xdr_string("%s"); // format field 130 xdr_string(value); // metric value 131 132 for (SocketAddress socketAddress : metricsServers) { 133 DatagramPacket packet = 134 new DatagramPacket(buffer, offset, socketAddress); 135 datagramSocket.send(packet); 136 } 137 } 138 139}