Java Metric使用介绍1
Metrics是一个给JAVA提供度量工具的包，在JAVA代码中嵌入Metrics代码，可以方便的对业务代码的各个指标进行监控，同时，Metrics能够很好的跟Ganlia、Graphite结合，方便的提供图形化接口。
下面简单介绍下Metrics如何使用。
Maven地址：
只需要增加metrics-core即可使用
<dependency>
<groupId>com.yammer.metrics</groupId>
<artifactId>metrics-core</artifactId>
<version>2.2.0</version>
</dependency>
源文档 <http://metrics.codahale.com/getting-started/>
下面通过一些测试代码介绍Metrics每个组件的使用，比较简单，基本看代码就懂了，这里不做过多介绍，请结合http://metrics.codahale.com/getting-started/介绍一起看，这里相当于完善代码。
Gauges
最简单的度量指标，每次相当于重置这个值。
package com.alibaba.cxf.test.metric;
import java.util.LinkedList;
import java.util.Queue;
import java.util.concurrent.TimeUnit;
import com.yammer.metrics.Metrics;
import com.yammer.metrics.core.Counter;
import com.yammer.metrics.core.Gauge;
import com.yammer.metrics.reporting.ConsoleReporter;
/**
* TODO
* @author scutshuxue.chenxf
*/
public class TestGauges {
public static Queue<String> queue = new LinkedList<String>();
public static void main(String[] args) throws InterruptedException{
ConsoleReporter.enable(5,TimeUnit.SECONDS);
Gauge<Integer>g = Metrics.newGauge(TestGauges.class, "pending-jobs", newGauge<Integer>() {
@Override
public Integer value() {
return queue.size();
}
});
queue.add("ssss");
System.out.println(g.value());
while(true){
Thread.sleep(1000);
}
}
}
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执行效果如下：
12-12-20 14:48:53==============================================================
com.alibaba.cxf.test.metric.TestGauges:
pending-jobs:
value = 1代码中都增加了ConsoleReporter.enable(1, TimeUnit.SECONDS);语句，通过这个命令，可以每秒钟将度量指标打印在屏幕上，理解起来会有更清楚的理解。
Counter，计数器
package com.alibaba.cxf.test.metric;
import java.util.LinkedList;
import java.util.Queue;
import java.util.concurrent.TimeUnit;
import com.yammer.metrics.Metrics;
import com.yammer.metrics.core.Counter;
import com.yammer.metrics.reporting.ConsoleReporter;
/**
* TODO
* @author scutshuxue.chenxf
*/
public class TestCounter {
private final Counter pendingJobs = Metrics.newCounter(TestCounter.class, "pending-jobs");
private final Queue<String> queue = new LinkedList<String>();
public void add(Stringstr) {
pendingJobs.inc();
queue.offer(str);
}
public String take() {
pendingJobs.dec();
return queue.poll();
}
/**
* TODO
* @author scutshuxue.chenxf
* @param args
* void
* @throws InterruptedException
*/
public static void main(String[]args) throws InterruptedException {
// TODOAuto-generated method stub
TestCounter tc =new TestCounter();
ConsoleReporter.enable(1,TimeUnit.SECONDS);
while(true){
tc.add("1");
Thread.sleep(1000);
}
}
}效果如下：
12-12-20 14:48:53==============================================================
com.alibaba.cxf.test.metric.TestGauges:
pending-jobs:
value = 1Meters
Meters会将最近1分钟，5分钟，15分钟的TPS（每秒处理的request数）给打印出来，还有所有时间的TPS。
package com.alibaba.cxf.test.metric;
import java.util.concurrent.TimeUnit;
import com.yammer.metrics.Metrics;
import com.yammer.metrics.core.Meter;
import com.yammer.metrics.reporting.ConsoleReporter;
/**
* TODO
* @author scutshuxue.chenxf
*/
public class TestMeters {
private static Meter meter = Metrics.newMeter(TestMeters.class, "requests","requests", TimeUnit.SECONDS);
public static void main(String[] args) throws InterruptedException{
ConsoleReporter.enable(1,TimeUnit.SECONDS);
while(true){
meter.mark();
meter.mark();
Thread.sleep(1000);
}
}
}效果如下：
12-12-20 15:02:50==============================================================
com.alibaba.cxf.test.metric.TestMeters:
requests:
count = 20
mean rate = 2.20requests/s
1-minute rate = 2.00requests/s
5-minute rate = 2.00requests/s
15-minute rate = 2.00requests/sHistograms 直方图
最大值，最小值，平均值，方差，中位值，百分比数据，如75%,90%,98%,99%的数据在哪个范围内。
package com.alibaba.cxf.test.metric;
import java.util.concurrent.TimeUnit;
import com.yammer.metrics.Metrics;
import com.yammer.metrics.core.Histogram;
import com.yammer.metrics.reporting.ConsoleReporter;
/**
* TODO
* @author scutshuxue.chenxf
*/
public class TestHistograms {
private static Histogram histo = Metrics.newHistogram(TestHistograms.class,"histo-sizes");
/**
* TODO
* @author scutshuxue.chenxf
* @param args
* void
* @throws InterruptedException
*/
public static void main(String[] args) throws InterruptedException {
// TODOAuto-generated method stub
ConsoleReporter.enable(1,TimeUnit.SECONDS);
int i=0;
while(true){
histo.update(i++);
Thread.sleep(1000);
}
}
}效果如下：
com.alibaba.cxf.test.metric.TestHistograms:
histo-sizes:
min = 0.00
max = 5.00
mean = 2.50
stddev = 1.87
median = 2.50
75% <= 4.25
95% <= 5.00
98% <= 5.00
99% <= 5.00
99.9% <= 5.00Timers
时间统计
package com.alibaba.cxf.test.metric;
import java.util.Random;
import java.util.concurrent.TimeUnit;
import com.yammer.metrics.Metrics;
import com.yammer.metrics.core.Timer;
import com.yammer.metrics.core.TimerContext;
import com.yammer.metrics.reporting.ConsoleReporter;
/**
* TODO
* @author scutshuxue.chenxf
*/
public class TestTimers {
private static Timer timer = Metrics.newTimer(TestTimers.class, "responses", TimeUnit.MILLISECONDS,TimeUnit.SECONDS);
/**
* TODO
* @author scutshuxue.chenxf
* @param args
* void
* @throws InterruptedException
*/
public static voidmain(String[] args) throws InterruptedException {
// TODOAuto-generated method stub
ConsoleReporter.enable(2,TimeUnit.SECONDS);
Random rn = newRandom();
timer.time();
System.out.println();
while(true){
TimerContextcontext = timer.time();
Thread.sleep(rn.nextInt(1000));
context.stop();
}
}
}效果如下:
com.alibaba.cxf.test.metric.TestTimers:
responses:
count = 26
mean rate = 2.15calls/s
1-minute rate = 1.70calls/s
5-minute rate = 1.62calls/s
15-minute rate = 1.61calls/s
min = 35.47ms
max = 878.76ms
mean = 462.50ms
stddev = 284.91ms
median = 419.90ms
75% <=764.13ms
95% <=877.76ms
98% <=878.76ms
99% <=878.76ms
99.9% <=878.76msHealth Checks
健康检查，如心跳：
package com.alibaba.cxf.test.metric;
import java.util.Map;
import java.util.Map.Entry;
import java.util.Random;
import java.util.concurrent.TimeUnit;
import com.yammer.metrics.HealthChecks;
import com.yammer.metrics.core.HealthCheck;
import com.yammer.metrics.reporting.ConsoleReporter;
public class DatabaseHealthCheck extends HealthCheck {
private static Databasedatabase;
private static final Map<String, Result> results = HealthChecks.runHealthChecks();
public DatabaseHealthCheck(Databasedatabase) {
super("database");
this.database =database;
}
@Override
public Result check()throws Exception {
if(database.isConnected()) {
returnResult.healthy();
} else {
return Result.unhealthy("Cannotconnect to database" );
}
}
public static void main(String[] args) throws Exception{
Database db = new Database();
DatabaseHealthCheck checkHealth = new DatabaseHealthCheck(db);
HealthChecks.register(checkHealth);
while(true){
Map<String,Result> results = HealthChecks.runHealthChecks();
for(Entry<String, Result> entry : results.entrySet()) {
if (entry.getValue().isHealthy()) {
System.out.println(entry.getKey() +" is healthy");
} else {
System.err.println(entry.getKey() +" is UNHEALTHY: " + entry.getValue().getMessage());
}
}
Thread.sleep(1000);
}
}
}
class Database{
static Random rn = newRandom();
public booleanisConnected() {
// TODOAuto-generated method stub
returnrn.nextBoolean();
}
}效果如下：
com.alibaba.cxf.test.metric.TestTimers:
responses:
count = 26
mean rate = 2.15calls/s
1-minute rate = 1.70calls/s
5-minute rate = 1.62calls/s
15-minute rate = 1.61calls/s
min = 35.47ms
max = 878.76ms
mean = 462.50ms
stddev = 284.91ms
median = 419.90ms
75% <=764.13ms
95% <=877.76ms
98% <=878.76ms
99% <=878.76ms
99.9% <=878.76ms