/*
* GangliaContext.java
*
* 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.metrics.ganglia;
import java.io.IOException;
import java.net.DatagramPacket;
import java.net.SocketAddress;
import java.net.UnknownHostException;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.metrics.ContextFactory;
import org.apache.hadoop.net.DNS;
/**
* Context for sending metrics to Ganglia version 3.1.x.
*
* 3.1.1 has a slightly different wire portal compared to 3.0.x.
*/
public class GangliaContext31 extends GangliaContext {
String hostName = "UNKNOWN.example.com";
private static final Log LOG =
LogFactory.getLog("org.apache.hadoop.util.GangliaContext31");
public void init(String contextName, ContextFactory factory) {
super.init(contextName, factory);
LOG.debug("Initializing the GangliaContext31 for Ganglia 3.1 metrics.");
// Take the hostname from the DNS class.
Configuration conf = new Configuration();
if (conf.get("slave.host.name") != null) {
hostName = conf.get("slave.host.name");
} else {
try {
hostName = DNS.getDefaultHost(
conf.get("dfs.datanode.dns.interface","default"),
conf.get("dfs.datanode.dns.nameserver","default"));
} catch (UnknownHostException uhe) {
LOG.error(uhe);
hostName = "UNKNOWN.example.com";
}
}
}
protected void emitMetric(String name, String type, String value)
throws IOException
{
if (name == null) {
LOG.warn("Metric was emitted with no name.");
return;
} else if (value == null) {
LOG.warn("Metric name " + name +" was emitted with a null value.");
} else if (type == null) {
LOG.warn("Metric name " + name + ", value " + value + " has no type.");
}
LOG.debug("Emitting metric " + name + ", type " + type + ", value " +
value + " from hostname" + hostName);
String units = getUnits(name);
if (units == null) {
LOG.warn("Metric name " + name + ", value " + value
+ " had 'null' units");
units = "";
}
int slope = getSlope(name);
int tmax = getTmax(name);
int dmax = getDmax(name);
offset = 0;
String groupName = name.substring(0,name.lastIndexOf("."));
// The following XDR recipe was done through a careful reading of
// gm_protocol.x in Ganglia 3.1 and carefully examining the output of
// the gmetric utility with strace.
// First we send out a metadata message
xdr_int(128); // metric_id = metadata_msg
xdr_string(hostName); // hostname
xdr_string(name); // metric name
xdr_int(0); // spoof = False
xdr_string(type); // metric type
xdr_string(name); // metric name
xdr_string(units); // units
xdr_int(slope); // slope
xdr_int(tmax); // tmax, the maximum time between metrics
xdr_int(dmax); // dmax, the maximum data value
xdr_int(1); /*Num of the entries in extra_value field for
Ganglia 3.1.x*/
xdr_string("GROUP"); /*Group attribute*/
xdr_string(groupName); /*Group value*/
for (SocketAddress socketAddress : metricsServers) {
DatagramPacket packet =
new DatagramPacket(buffer, offset, socketAddress);
datagramSocket.send(packet);
}
// Now we send out a message with the actual value.
// Technically, we only need to send out the metadata message once for
// each metric, but I don't want to have to record which metrics we did and
// did not send.
offset = 0;
xdr_int(133); // we are sending a string value
xdr_string(hostName); // hostName
xdr_string(name); // metric name
xdr_int(0); // spoof = False
xdr_string("%s"); // format field
xdr_string(value); // metric value
for (SocketAddress socketAddress : metricsServers) {
DatagramPacket packet =
new DatagramPacket(buffer, offset, socketAddress);
datagramSocket.send(packet);
}
}
}