基于JRobin的网络监控管理

在网络环境下，Ping是一个很重要的命令，通常用来检测远程的机器是否能够连通以及连接的质量如何。如果定时Ping一些机器，然后将响应时间在时间轴上画成图像，那就能非常直观的显示出网络信息，达到减脂网络的目的。

JRobin是一个很好的存储和用图形展示基于时间序列数据的工具。可以使用Java编写代码将操作系统中的Ping命令与JRobin结合起来，通过Ping命令获取数据信息，用JRobin保存和以图形方式显示Ping的响应时间，从而开发出一个简单的网络监视工具。

1、Ping

Ping命令的用法很简单，一般在其后接目标机器的域名或IP地址。不过Windows和Linux下的用法有所不同：

（1）在Windows下，执行 ping www.baidu.com 命令后，连续Ping四次，然后返回结果；在Linux下，执行同样的命令好，一直Ping下去，直到使用Ctrl+C终止该命令。

（2）在Windows下，通过 -n 来指定Ping的次数；在Linux下，使用 -c 选项。

2、JRobin

JRobin的介绍可以参考：

（1）JRobin网站：http://www.jrobin.org/

（2）JRobin简介：http://hi.baidu.com/li_zhongnan/blog/item/6fef0499a408940d6e068cbf.html

3、在Java中的实现机制：

（1）获取Ping响应时间：通过ProcessBuilder创建一个代表外部Ping命令的Process，启动Process执行Ping命令，获取Ping命令的标准输出，对标准输出进行解析，取出响应时间数据。如果需要能在Windows和Linux平台上执行，可以通过环境变量判断平台然后选择针对不同的平台、带不同的参数、执行不同的命令、用不同的方法解析命令输出，最终输出相同的结果。

在Java中执行外部命令可以参考：http://hi.baidu.com/li_zhongnan/blog/item/318effa9611d2bf91f17a26a.html

（2）保存历史数据：使用JRobin的机制来保存Ping的历史数据。

（3）定时执行：将执行Ping命令获取响应时间、保存相应时间数据到JRobin封装在一个函数，在TimerTask中调用该函数，通过Timer调度来定时执行。

（4）生成图形：使用JRobin来生成Ping响应时间图形。

（5）扩展性考虑：

a. 通过参数设置多个需要监视的对象，可以对多个域名或IP地址进行监视并将数据画在衣服图上；

b. 可以指定数据和图形的保存目录；

c. 提供启动和停止监视的功能；

d. 可以随时调用生成图形的操作，从而可以实现实时监控的功能。

4、看看成果：

5、事例代码：

import java.awt.Color;
import java.awt.Font;
import java.io.BufferedReader;
import java.io.File;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.util.ArrayList;
import java.util.Date;
import java.util.List;
import java.util.Timer;
import java.util.TimerTask;
import java.util.logging.Logger;

import org.jrobin.core.RrdDb;
import org.jrobin.core.RrdDef;
import org.jrobin.core.Sample;
import org.jrobin.graph.RrdGraph;
import org.jrobin.graph.RrdGraphDef;

public class PingMonitor {

public static String[] execute(String command) {
String[] strs = null;
File scriptFile = null;
try {
List<String> cmdList = new ArrayList<String>();
String osName = System.getProperty(”os.name”);
if (osName.indexOf(”Windows”) > -1) {
cmdList.add(”CMD.EXE”);
cmdList.add(”/C”);
cmdList.add(command);
} else {
scriptFile = File.createTempFile(”monitor”, “.sh”);
cmdList.add(”/bin/bash”);

String fileName = scriptFile.getCanonicalPath();
PrintWriter writer = new PrintWriter(scriptFile);
writer.println(command);

writer.flush();
writer.close();
cmdList.add(fileName);
}

ProcessBuilder pb = new ProcessBuilder(cmdList);
Process p = pb.start();

p.waitFor();

String line = null;
BufferedReader stdout = new BufferedReader(new InputStreamReader(p
.getInputStream()));
List<String> stdoutList = new ArrayList<String>();
while ((line = stdout.readLine()) != null) {
stdoutList.add(line);
}

BufferedReader stderr = new BufferedReader(new InputStreamReader(p
.getErrorStream()));
List<String> stderrList = new ArrayList<String>();
while ((line = stderr.readLine()) != null) {
stderrList.add(line);
}

strs = stdoutList.toArray(new String[0]);
} catch (Exception e) {
e.printStackTrace();
} finally {
if (scriptFile != null)
scriptFile.delete();
}

return strs;
}

private String dataFormat = “%5.1f ms”;
private Logger logger = Logger.getLogger(this.getClass().getName());
private String monitorName = “ping”;
private String[] hosts = null;
private String dataDir = “.”;
private int step = 10;
private String rrdPath = “”;
private Timer timer = new Timer();
private long timeStart = 0;
protected int width = 600;
protected int height = 150;

public PingMonitor(String[] hosts, String dataDir, int step) {
this.hosts = hosts;
this.dataDir = dataDir;
this.step = step;
this.rrdPath = this.dataDir + File.separator + monitorName + “.rrd”;
}

public String generateGraph() {
long timeCur = org.jrobin.core.Util.getTimestamp();
return generateGraph(timeStart, timeCur);
}

public String generateGraph(long start, long end) {
RrdDb rrdDb = null;
try {
Color[] colors = new Color[] { Color.GREEN, Color.BLUE,
Color.MAGENTA, Color.YELLOW, Color.RED, Color.CYAN,
Color.ORANGE, Color.PINK, Color.BLACK};
String graphPath = this.dataDir + File.separator + monitorName
+ “.png”;

// create graph
logger.info(”Creating graph”);
RrdGraphDef gDef = new RrdGraphDef();
gDef.setWidth(width);
gDef.setHeight(height);
gDef.setFilename(graphPath);
gDef.setStartTime(start);
gDef.setEndTime(end);

gDef.setTitle(”Ping 命令响应时间”);
gDef.setVerticalLabel(”毫秒”);

String[] dsNames = null;

rrdDb = new RrdDb(rrdPath);
dsNames = rrdDb.getDsNames();

for (int i = 0; i < dsNames.length; i++) {
String dsName = dsNames[i];
String legend = dsName;
if (legend == null || legend.equals(”"))
legend = dsName;
gDef.datasource(dsName, rrdPath, dsName, “AVERAGE”);
gDef.line(dsName, colors[i % colors.length], legend, 2);

gDef.gprint(dsName, “MIN”, dataFormat + ” Min”);
gDef.gprint(dsName, “AVERAGE”, dataFormat + ” Avg”);
gDef.gprint(dsName, “MAX”, dataFormat + ” Max”);
gDef.gprint(dsName, “LAST”, dataFormat + ” Last\\r”);

gDef.print(dsName, “MIN”, “min” + dsName + ” = %.3f”);
gDef.print(dsName, “AVERAGE”, “avg” + dsName + ” = %.3f”);
gDef.print(dsName, “MAX”, “max” + dsName + ” = %.3f”);
gDef.print(dsName, “LAST”, “last” + dsName + ” = %.3f”);
}

gDef.setImageInfo(”<img src=’%s’ width=’%d’ height = ‘%d’>”);
gDef.setPoolUsed(false);
gDef.setImageFormat(”png”);

gDef.setSmallFont(new Font(”Monospaced”, Font.PLAIN, 11));
gDef.setLargeFont(new Font(”SansSerif”, Font.BOLD, 14));
// gDef.setAltYMrtg(true);

// create graph finally
RrdGraph graph = new RrdGraph(gDef);

// logger.info(graph.getRrdGraphInfo().dump());
logger.info(”Graph created”);

return graph.getRrdGraphInfo().getFilename();
} catch (Exception e) {
logger.warning(”Error in generating graph: ” + e.getMessage());
} finally {
if (rrdDb != null)
try {
rrdDb.close();
} catch (IOException e) {
e.printStackTrace();
}
}
return null;
}

private double getReplyTime(String[] strs) {
double value = Double.NaN;
if (strs != null) {
for (int j = 0; j < strs.length; j++) {
String str = strs[j];
int n1 = str.indexOf(”time=”);
int n2 = str.indexOf(”ms”, n1);
if (n1 > 0 && n2 > n1) {
String s = str.substring(n1 + “time=”.length(), n2).trim();
try {
value = Double.parseDouble(s);
} catch (Exception e) {
}
break;
}
}
}
return value;
}

/**
* Return a HashMap which contains the current value of each data source.
*
* @return the current value of each data source.
*/
public double getValue(String host) {
String command = “”;
String osName = System.getProperty(”os.name”);
if (osName.indexOf(”Windows”) > -1) {
command = “ping ” + host + ” -n 1″;

} else {
command = “ping ” + host + ” -c 1″;
}
return getReplyTime(execute(command));
}

/**
* Initialization.
*/
public void initialize() throws Exception {
RrdDb rrdDb = null;
try {
rrdDb = new RrdDb(rrdPath);
} catch (Exception e) {
}

if (rrdDb == null) {
logger.info(”RRD data is not located in ” + rrdPath
+ “, create a new one”);

RrdDef rrdDef = new RrdDef(rrdPath, timeStart - 1, step);

for (int i = 0; i < hosts.length; i++)
rrdDef
.addDatasource(hosts[i], “GAUGE”, 2 * step, 0,
Double.NaN);
rrdDef.addArchive(”AVERAGE”, 0.5, 1, 24 * 3600 / step);
rrdDef.addArchive(”AVERAGE”, 0.5, 300 / step, 7 * 288);

logger.info(”Estimated file size: ” + rrdDef.getEstimatedSize());
rrdDb = new RrdDb(rrdDef);
logger.info(”RRD file created.”);
}

logger.info(monitorName + ” RRD Db Defs: ” + rrdDb.getRrdDef().dump());
if (rrdDb != null)
rrdDb.close();
}

/**
* Start monitor.
*
* @return true if succeed, else false.
*/
public boolean start() {
logger.info(”start to monitor ” + monitorName);

try {
timeStart = org.jrobin.core.Util.getTimestamp();
initialize();
timer.scheduleAtFixedRate(new TimerTask() {
public void run() {
try {
updateData();
} catch (Exception e) {
e.printStackTrace();
logger.severe(”Timer running error: ” + e.getMessage());
}
}
}, 0, step * 1000);
return true;
} catch (Exception e) {
e.printStackTrace();
}
return false;
}

/**
* Stop monitor.
*/
public void stop() {
timer.cancel();
}

private void updateData() throws Exception {
RrdDb rrdDb = null;
try {
logger.info(”update rrd data for ” + monitorName);

rrdDb = new RrdDb(rrdPath);
String[] dsNames = rrdDb.getDsNames();

long lastUpdateTime = rrdDb.getLastUpdateTime();
long t = org.jrobin.core.Util.getTimestamp();
if (t > lastUpdateTime) {
rrdDb.setInfo(”T=” + t);
Sample sample = rrdDb.createSample();
sample.setTime(t);
for (int i = 0; i < dsNames.length; i++) {
String dsName = dsNames[i];
Double value = getValue(dsName);
logger.fine(dsName + ” = ” + value);
if (value == null)
value = Double.NaN;
sample.setValue(dsName, value);
}
sample.update();
} else {
logger.warning(”Bad sample time ” + t + “(”
+ new Date(t * 1000L) + “)” + new Date()
+ “, the last update time was ” + lastUpdateTime + “(”
+ new Date(lastUpdateTime * 1000L) + “) - ”
+ monitorName);
}
} finally {
if (rrdDb != null)
try {
rrdDb.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}

public static void main(String[] args) {
String[] hosts = new String[] { “ www.baidu.com “, “ www.google.cn ” };
PingMonitor p = new PingMonitor(hosts, “.”, 10);
p.start();

try {
Thread.sleep(10 * 60 * 1000);
} catch (InterruptedException e) {
e.printStackTrace();
}

p.stop();
p.generateGraph();
}
}