/*
* 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.flume.instrumentation;
import java.net.DatagramPacket;
import java.net.DatagramSocket;
import java.net.InetAddress;
import java.net.InetSocketAddress;
import java.net.SocketAddress;
import java.net.SocketException;
import java.util.ArrayList;
import java.util.List;
import java.util.Map;
import java.util.concurrent.Executors;
import java.util.concurrent.ScheduledExecutorService;
import java.util.concurrent.TimeUnit;
import org.apache.flume.Context;
import org.apache.flume.FlumeException;
import org.apache.flume.api.HostInfo;
import org.apache.flume.conf.ConfigurationException;
import org.apache.flume.instrumentation.util.JMXPollUtil;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
/**
* A Ganglia server that polls JMX based at a configured frequency (defaults to
* once every 60 seconds). This implementation can send data to ganglia 3 and
* ganglia 3.1. <p>
*
* <b>Mandatory Parameters:</b><p> <tt>hosts: </tt> List of comma separated
* hostname:ports of ganglia servers to report metrics to. <p> <b>Optional
* Parameters: </b><p> <tt>pollFrequency:</tt>Interval in seconds between
* consecutive reports to ganglia servers. Default = 60 seconds.<p>
* <tt>isGanglia3:</tt> Report to ganglia 3 ? Default = false - reports to
* ganglia 3.1.
*
*
*
*/
public class GangliaServer implements MonitorService {
/*
* The Ganglia protocol specific stuff: the xdr_* methods
* and the sendToGanglia* methods have been shamelessly ripped off
* from Hadoop. All hail the yellow elephant!
*/
private static final Logger logger =
LoggerFactory.getLogger(GangliaServer.class);
public static final int BUFFER_SIZE = 1500; // as per libgmond.c
protected byte[] buffer = new byte[BUFFER_SIZE];
protected int offset;
private final List<SocketAddress> addresses = new ArrayList<SocketAddress>();
private DatagramSocket socket = null;
private ScheduledExecutorService service =
Executors.newSingleThreadScheduledExecutor();
private List<HostInfo> hosts;
protected final GangliaCollector collectorRunnable;
private int pollFrequency = 60;
public static final String DEFAULT_UNITS = "";
public static final int DEFAULT_TMAX = 60;
public static final int DEFAULT_DMAX = 0;
public static final int DEFAULT_SLOPE = 3;
public static final String GANGLIA_DOUBLE_TYPE = "double";
private volatile boolean isGanglia3 = false;
private String hostname;
public final String CONF_POLL_FREQUENCY = "pollFrequency";
public final int DEFAULT_POLL_FREQUENCY = 60;
public final String CONF_HOSTS = "hosts";
public final String CONF_ISGANGLIA3 = "isGanglia3";
private static final String GANGLIA_CONTEXT = "flume.";
/**
*
* @param hosts List of hosts to send the metrics to. All of them have to be
* running the version of ganglia specified by the configuration.
* @throws FlumeException
*/
public GangliaServer() throws FlumeException {
collectorRunnable = new GangliaCollector();
}
/**
* Puts a string into the buffer by first writing the size of the string as an
* int, followed by the bytes of the string, padded if necessary to a multiple
* of 4.
*
* @param s the string to be written to buffer at offset location
*/
protected void xdr_string(String s) {
byte[] bytes = s.getBytes();
int len = bytes.length;
xdr_int(len);
System.arraycopy(bytes, 0, buffer, offset, len);
offset += len;
pad();
}
/**
* Pads the buffer with zero bytes up to the nearest multiple of 4.
*/
private void pad() {
int newOffset = ((offset + 3) / 4) * 4;
while (offset < newOffset) {
buffer[offset++] = 0;
}
}
/**
* Puts an integer into the buffer as 4 bytes, big-endian.
*/
protected void xdr_int(int i) {
buffer[offset++] = (byte) ((i >> 24) & 0xff);
buffer[offset++] = (byte) ((i >> 16) & 0xff);
buffer[offset++] = (byte) ((i >> 8) & 0xff);
buffer[offset++] = (byte) (i & 0xff);
}
public synchronized void sendToGangliaNodes() {
DatagramPacket packet;
for (SocketAddress addr : addresses) {
try {
packet = new DatagramPacket(buffer, offset, addr);
socket.send(packet);
} catch (Exception ex) {
logger.warn("Could not send metrics to metrics server: "
+ addr.toString(), ex);
}
}
offset = 0;
}
/**
* Start this server, causing it to poll JMX at the configured frequency.
*/
@Override
public void start() {
try {
socket = new DatagramSocket();
hostname = InetAddress.getLocalHost().getHostName();
} catch (SocketException ex) {
logger.error("Could not create socket for metrics collection.");
throw new FlumeException(
"Could not create socket for metrics collection.", ex);
} catch (Exception ex2) {
logger.warn("Unknown error occured", ex2);
}
for (HostInfo host : hosts) {
addresses.add(new InetSocketAddress(
host.getHostName(), host.getPortNumber()));
}
collectorRunnable.server = this;
if (service.isShutdown() || service.isTerminated()) {
service = Executors.newSingleThreadScheduledExecutor();
}
service.scheduleWithFixedDelay(collectorRunnable, 0,
pollFrequency, TimeUnit.SECONDS);
}
/**
* Stop this server.
*/
@Override
public void stop() {
service.shutdown();
while (!service.isTerminated()) {
try {
logger.warn("Waiting for ganglia service to stop");
service.awaitTermination(500, TimeUnit.MILLISECONDS);
} catch (InterruptedException ex) {
logger.warn("Interrupted while waiting"
+ " for ganglia monitor to shutdown", ex);
service.shutdownNow();
}
}
addresses.clear();
}
/**
*
* @param pollFrequency Seconds between consecutive JMX polls.
*/
public void setPollFrequency(int pollFrequency) {
this.pollFrequency = pollFrequency;
}
/**
*
* @return Seconds between consecutive JMX polls
*/
public int getPollFrequency() {
return pollFrequency;
}
/**
*
* @param isGanglia3 When true, ganglia 3 messages will be sent, else Ganglia
* 3.1 formatted messages are sent.
*/
public void setIsGanglia3(boolean isGanglia3) {
this.isGanglia3 = isGanglia3;
}
/**
*
* @return True if the server is currently sending ganglia 3 formatted msgs.
* False if the server returns Ganglia 3.1
*/
public boolean isGanglia3() {
return this.isGanglia3;
}
protected void createGangliaMessage(String name, String value) {
logger.debug("Sending ganglia3 formatted message."
+ name + ": " + value);
name = hostname + "." + name;
xdr_int(0);
String type = "string";
try {
Float.parseFloat(value);
type = "float";
} catch (NumberFormatException ex) {
// The param is a string, and so leave the type as is.
}
xdr_string(type); // metric type
xdr_string(name);
xdr_string(value);
xdr_string(DEFAULT_UNITS);
xdr_int(DEFAULT_SLOPE);
xdr_int(DEFAULT_TMAX);
xdr_int(DEFAULT_DMAX);
}
protected void createGangliaMessage31(String name, String value) {
logger.debug("Sending ganglia 3.1 formatted message: "
+ name + ": " + value);
xdr_int(128); // metric_id = metadata_msg
xdr_string(hostname); // hostname
xdr_string(name); // metric name
xdr_int(0); // spoof = False
String type = "string";
try {
Float.parseFloat(value);
type = "float";
} catch (NumberFormatException ex) {
// The param is a string, and so leave the type as is.
}
xdr_string(type); // metric type
xdr_string(name); // metric name
xdr_string(DEFAULT_UNITS); // units
xdr_int(DEFAULT_SLOPE); // slope
xdr_int(DEFAULT_TMAX); // tmax, the maximum time between metrics
xdr_int(DEFAULT_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("flume"); /*Group value*/
this.sendToGangliaNodes();
// 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.
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
}
@Override
public void configure(Context context) {
this.pollFrequency = context.getInteger(this.CONF_POLL_FREQUENCY, 60);
String localHosts = context.getString(this.CONF_HOSTS);
if (localHosts == null || localHosts.isEmpty()) {
throw new ConfigurationException("Hosts list cannot be empty.");
}
this.hosts = this.getHostsFromString(localHosts);
this.isGanglia3 = context.getBoolean(this.CONF_ISGANGLIA3, false);
}
private List<HostInfo> getHostsFromString(String hosts)
throws FlumeException {
List<HostInfo> hostInfoList = new ArrayList<HostInfo>();
String[] hostsAndPorts = hosts.split(",");
int i = 0;
for (String host : hostsAndPorts) {
String[] hostAndPort = host.split(":");
if (hostAndPort.length < 2) {
logger.warn("Invalid ganglia host: ", host);
continue;
}
try {
hostInfoList.add(new HostInfo("ganglia_host-" + String.valueOf(i),
hostAndPort[0], Integer.parseInt(hostAndPort[1])));
} catch (Exception e) {
logger.warn("Invalid ganglia host: " + host, e);
continue;
}
}
if (hostInfoList.isEmpty()) {
throw new FlumeException("No valid ganglia hosts defined!");
}
return hostInfoList;
}
/**
* Worker which polls JMX for all mbeans with
* {@link javax.management.ObjectName} within the flume namespace:
* org.apache.flume. All attributes of such beans are sent to the all hosts
* specified by the server that owns it's instance.
*
*/
protected class GangliaCollector implements Runnable {
private GangliaServer server;
@Override
public void run() {
try {
Map<String, Map<String, String>> metricsMap =
JMXPollUtil.getAllMBeans();
for (String component : metricsMap.keySet()) {
Map<String, String> attributeMap = metricsMap.get(component);
for (String attribute : attributeMap.keySet()) {
if (isGanglia3) {
server.createGangliaMessage(GANGLIA_CONTEXT + component + "."
+ attribute,
attributeMap.get(attribute));
} else {
server.createGangliaMessage31(GANGLIA_CONTEXT + component + "."
+ attribute,
attributeMap.get(attribute));
}
server.sendToGangliaNodes();
}
}
} catch (Throwable t) {
logger.error("Unexpected error", t);
}
}
}
}