Metrics是一个给JAVA服务的各项指标提供度量工具的包,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。基本使用方式直接将core包(目前稳定版本3.0.1)导入pom文件即可,配置如下:
<dependency> <groupId>com.codahale.metricsgroupId> <artifactId>metrics-coreartifactId> <version>3.0.1version> dependency>
core包主要提供如下核心功能:
-
Metrics Registries类似一个metrics容器,维护一个Map,可以是一个服务一个实例。
-
支持五种metric类型:Gauges、Counters、Meters、Histograms和Timers。
-
可以将metrics值通过JMX、Console,CSV文件和SLF4J loggers发布出来。
五种Metrics类型:
1. Gauges
Gauges是一个最简单的计量,一般用来统计瞬时状态的数据信息,比如系统中处于pending状态的job。测试代码
-
package com.netease.test.metrics;
-
-
import com.codahale.metrics.ConsoleReporter;
-
import com.codahale.metrics.Gauge;
-
import com.codahale.metrics.JmxReporter;
-
import com.codahale.metrics.MetricRegistry;
-
-
import java.util.Queue;
-
import java.util.concurrent.LinkedBlockingDeque;
-
import java.util.concurrent.TimeUnit;
-
-
/**
-
* User: hzwangxx
-
* Date: 14-2-17
-
* Time: 14:47
-
* 测试Gauges,实时统计pending状态的job个数
-
*/
-
public class TestGauges {
-
/**
-
* 实例化一个registry,最核心的一个模块,相当于一个应用程序的metrics系统的容器,维护一个Map
-
*/
-
private static final MetricRegistry metrics = new MetricRegistry();
-
-
private static Queue<String> queue = new LinkedBlockingDeque<String>();
-
-
/**
-
* 在控制台上打印输出
-
*/
-
private static ConsoleReporter reporter = ConsoleReporter.forRegistry(metrics).build();
-
-
public static void main(String[] args) throws InterruptedException {
-
reporter.start(3, TimeUnit.SECONDS);
-
-
//实例化一个Gauge
-
Gauge<Integer> gauge = new Gauge<Integer>() {
-
@Override
-
public Integer getValue() {
-
return queue.size();
-
}
-
};
-
-
//注册到容器中
-
metrics.register(MetricRegistry.name(TestGauges.class, "pending-job", "size"), gauge);
-
-
//测试JMX
-
JmxReporter jmxReporter = JmxReporter.forRegistry(metrics).build();
-
jmxReporter.start();
-
-
//模拟数据
-
for (int i=0; i<20; i++){
-
queue.add("a");
-
Thread.sleep(1000);
-
}
-
-
}
-
}
-
-
/*
-
console output:
-
14-2-17 15:29:35 ===============================================================
-
-
-- Gauges ----------------------------------------------------------------------
-
com.netease.test.metrics.TestGauges.pending-job.size
-
value = 4
-
-
-
14-2-17 15:29:38 ===============================================================
-
-
-- Gauges ----------------------------------------------------------------------
-
com.netease.test.metrics.TestGauges.pending-job.size
-
value = 6
-
-
-
14-2-17 15:29:41 ===============================================================
-
-
-- Gauges ----------------------------------------------------------------------
-
com.netease.test.metrics.TestGauges.pending-job.size
-
value = 9
-
*/
通过以上步骤将会向MetricsRegistry容器中注册一个名字为com.netease.test.metrics .TestGauges.pending-job.size的metrics,实时获取队列长度的指标。另外,Core包种还扩展了几种特定的Gauge:
-
JMX Gauges—提供给第三方库只通过JMX将指标暴露出来。
-
Ratio Gauges—简单地通过创建一个gauge计算两个数的比值。
-
Cached Gauges—对某些计量指标提供缓存
Derivative Gauges—提供Gauge的值是基于其他Gauge值的接口。
2. Counter
Counter是Gauge的一个特例,维护一个计数器,可以通过inc()和dec()方法对计数器做修改。使用步骤与Gauge基本类似,在MetricRegistry中提供了静态方法可以直接实例化一个Counter。
-
package com.netease.test.metrics;
-
-
import com.codahale.metrics.ConsoleReporter;
-
import com.codahale.metrics.Counter;
-
import com.codahale.metrics.MetricRegistry;
-
-
import java.util.LinkedList;
-
import java.util.Queue;
-
import java.util.concurrent.TimeUnit;
-
import static com.codahale.metrics.MetricRegistry.*;
-
/**
-
* User: hzwangxx
-
* Date: 14-2-14
-
* Time: 14:02
-
* 测试Counter
-
*/
-
public class TestCounter {
-
-
/**
-
* 实例化一个registry,最核心的一个模块,相当于一个应用程序的metrics系统的容器,维护一个Map
-
*/
-
private static final MetricRegistry metrics = new MetricRegistry();
-
-
/**
-
* 在控制台上打印输出
-
*/
-
private static ConsoleReporter reporter = ConsoleReporter.forRegistry(metrics).build();
-
-
/**
-
* 实例化一个counter,同样可以通过如下方式进行实例化再注册进去
-
* pendingJobs = new Counter();
-
* metrics.register(MetricRegistry.name(TestCounter.class, "pending-jobs"), pendingJobs);
-
*/
-
private static Counter pendingJobs = metrics.counter(name(TestCounter.class, "pedding-jobs"));
-
// private static Counter pendingJobs = metrics.counter(MetricRegistry.name(TestCounter.class, "pedding-jobs"));
-
-
-
-
private static Queue<String> queue = new LinkedList<String>();
-
-
public static void add(String str) {
-
pendingJobs.inc();
-
queue.offer(str);
-
}
-
-
public String take() {
-
pendingJobs.dec();
-
return queue.poll();
-
}
-
-
public static void main(String[]args) throws InterruptedException {
-
reporter.start(3, TimeUnit.SECONDS);
-
while(true){
-
add("1");
-
Thread.sleep(1000);
-
}
-
-
}
-
}
-
-
/*
-
console output:
-
14-2-17 17:52:34 ===============================================================
-
-
-- Counters --------------------------------------------------------------------
-
com.netease.test.metrics.TestCounter.pedding-jobs
-
count = 4
-
-
-
14-2-17 17:52:37 ===============================================================
-
-
-- Counters --------------------------------------------------------------------
-
com.netease.test.metrics.TestCounter.pedding-jobs
-
count = 6
-
-
-
14-2-17 17:52:40 ===============================================================
-
-
-- Counters --------------------------------------------------------------------
-
com.netease.test.metrics.TestCounter.pedding-jobs
-
count = 9
-
-
*/
Meters用来度量某个时间段的平均处理次数(request per second),每1、5、15分钟的TPS。比如一个service的请求数,通过metrics.meter()实例化一个Meter之后,然后通过meter.mark()方法就能将本次请求记录下来。统计结果有总的请求数,平均每秒的请求数,以及最近的1、5、15分钟的平均TPS。
-
package com.netease.test.metrics;
-
-
import com.codahale.metrics.ConsoleReporter;
-
import com.codahale.metrics.Meter;
-
import com.codahale.metrics.MetricRegistry;
-
-
import java.util.concurrent.TimeUnit;
-
-
import static com.codahale.metrics.MetricRegistry.*;
-
-
/**
-
* User: hzwangxx
-
* Date: 14-2-17
-
* Time: 18:34
-
* 测试Meters
-
*/
-
public class TestMeters {
-
/**
-
* 实例化一个registry,最核心的一个模块,相当于一个应用程序的metrics系统的容器,维护一个Map
-
*/
-
private static final MetricRegistry metrics = new MetricRegistry();
-
-
/**
-
* 在控制台上打印输出
-
*/
-
private static ConsoleReporter reporter = ConsoleReporter.forRegistry(metrics).build();
-
-
/**
-
* 实例化一个Meter
-
*/
-
private static final Meter requests = metrics.meter(name(TestMeters.class, "request"));
-
-
public static void handleRequest() {
-
requests.mark();
-
}
-
-
public static void main(String[] args) throws InterruptedException {
-
reporter.start(3, TimeUnit.SECONDS);
-
while(true){
-
handleRequest();
-
Thread.sleep(100);
-
}
-
}
-
-
}
-
-
/*
-
14-2-17 18:43:08 ===============================================================
-
-
-- Meters ----------------------------------------------------------------------
-
com.netease.test.metrics.TestMeters.request
-
count = 30
-
mean rate = 9.95 events/second
-
1-minute rate = 0.00 events/second
-
5-minute rate = 0.00 events/second
-
15-minute rate = 0.00 events/second
-
-
-
14-2-17 18:43:11 ===============================================================
-
-
-- Meters ----------------------------------------------------------------------
-
com.netease.test.metrics.TestMeters.request
-
count = 60
-
mean rate = 9.99 events/second
-
1-minute rate = 10.00 events/second
-
5-minute rate = 10.00 events/second
-
15-minute rate = 10.00 events/second
-
-
-
14-2-17 18:43:14 ===============================================================
-
-
-- Meters ----------------------------------------------------------------------
-
com.netease.test.metrics.TestMeters.request
-
count = 90
-
mean rate = 9.99 events/second
-
1-minute rate = 10.00 events/second
-
5-minute rate = 10.00 events/second
-
15-minute rate = 10.00 events/second
-
*/
Histograms主要使用来统计数据的分布情况,最大值、最小值、平均值、中位数,百分比(75%、90%、95%、98%、99%和99.9%)。例如,需要统计某个页面的请求响应时间分布情况,可以使用该种类型的Metrics进行统计。具体的样例代码如下:
-
package com.netease.test.metrics;
-
-
import com.codahale.metrics.ConsoleReporter;
-
import com.codahale.metrics.Histogram;
-
import com.codahale.metrics.MetricRegistry;
-
-
import java.util.Random;
-
import java.util.concurrent.TimeUnit;
-
-
import static com.codahale.metrics.MetricRegistry.name;
-
-
/**
-
* User: hzwangxx
-
* Date: 14-2-17
-
* Time: 18:34
-
* 测试Histograms
-
*/
-
public class TestHistograms {
-
/**
-
* 实例化一个registry,最核心的一个模块,相当于一个应用程序的metrics系统的容器,维护一个Map
-
*/
-
private static final MetricRegistry metrics = new MetricRegistry();
-
-
/**
-
* 在控制台上打印输出
-
*/
-
private static ConsoleReporter reporter = ConsoleReporter.forRegistry(metrics).build();
-
-
/**
-
* 实例化一个Histograms
-
*/
-
private static final Histogram randomNums = metrics.histogram(name(TestHistograms.class, "random"));
-
-
public static void handleRequest(double random) {
-
randomNums.update((int) (random*100));
-
}
-
-
public static void main(String[] args) throws InterruptedException {
-
reporter.start(3, TimeUnit.SECONDS);
-
Random rand = new Random();
-
while(true){
-
handleRequest(rand.nextDouble());
-
Thread.sleep(100);
-
}
-
}
-
-
}
-
-
/*
-
14-2-17 19:39:11 ===============================================================
-
-
-- Histograms ------------------------------------------------------------------
-
com.netease.test.metrics.TestHistograms.random
-
count = 30
-
min = 1
-
max = 97
-
mean = 45.93
-
stddev = 29.12
-
median = 39.50
-
75% <= 71.00
-
95% <= 95.90
-
98% <= 97.00
-
99% <= 97.00
-
99.9% <= 97.00
-
-
-
14-2-17 19:39:14 ===============================================================
-
-
-- Histograms ------------------------------------------------------------------
-
com.netease.test.metrics.TestHistograms.random
-
count = 60
-
min = 0
-
max = 97
-
mean = 41.17
-
stddev = 28.60
-
median = 34.50
-
75% <= 69.75
-
95% <= 92.90
-
98% <= 96.56
-
99% <= 97.00
-
99.9% <= 97.00
-
-
-
14-2-17 19:39:17 ===============================================================
-
-
-- Histograms ------------------------------------------------------------------
-
com.netease.test.metrics.TestHistograms.random
-
count = 90
-
min = 0
-
max = 97
-
mean = 44.67
-
stddev = 28.47
-
median = 43.00
-
75% <= 71.00
-
95% <= 91.90
-
98% <= 96.18
-
99% <= 97.00
-
99.9% <= 97.00
-
*/
5. Timers
Timers主要是用来统计某一块代码段的执行时间以及其分布情况,具体是基于Histograms和Meters来实现的。样例代码如下:
Metrics提供了一个独立的模块:Health Checks,用于对Application、其子模块或者关联模块的运行是否正常做检测。该模块是独立metrics-core模块的,使用时则导入metrics-healthchecks包。
<dependency> <groupId>com.codahale.metricsgroupId> <artifactId>metrics-healthchecksartifactId> <version>3.0.1version> dependency>
使用起来和与上述几种类型的Metrics有点类似,但是需要重新实例化一个Metrics容器HealthCheckRegistry,待检测模块继承抽象类HealthCheck并实现check()方法即可,然后将该模块注册到HealthCheckRegistry中,判断的时候通过isHealthy()接口即可。如下示例代码:
-
package com.netease.test.metrics;
-
-
import com.codahale.metrics.health.HealthCheck;
-
import com.codahale.metrics.health.HealthCheckRegistry;
-
-
import java.util.Map;
-
import java.util.Random;
-
-
/**
-
* User: hzwangxx
-
* Date: 14-2-18
-
* Time: 9:57
-
*/
-
public class DatabaseHealthCheck extends HealthCheck{
-
private final Database database;
-
-
public DatabaseHealthCheck(Database database) {
-
this.database = database;
-
}
-
-
@Override
-
protected Result check() throws Exception {
-
if (database.ping()) {
-
return Result.healthy();
-
}
-
return Result.unhealthy("Can't ping database.");
-
}
-
-
/**
-
* 模拟Database对象
-
*/
-
static class Database {
-
/**
-
* 模拟database的ping方法
-
* @return 随机返回boolean值
-
*/
-
public boolean ping() {
-
Random random = new Random();
-
return random.nextBoolean();
-
}
-
}
-
-
public static void main(String[] args) {
-
// MetricRegistry metrics = new MetricRegistry();
-
// ConsoleReporter reporter = ConsoleReporter.forRegistry(metrics).build();
-
HealthCheckRegistry registry = new HealthCheckRegistry();
-
registry.register("database1", new DatabaseHealthCheck(new Database()));
-
registry.register("database2", new DatabaseHealthCheck(new Database()));
-
while (true) {
-
for (Map.Entry<String, Result> entry : registry.runHealthChecks().entrySet()) {
-
if (entry.getValue().isHealthy()) {
-
System.out.println(entry.getKey() + ": OK");
-
} else {
-
System.err.println(entry.getKey() + ": FAIL, error message: " + entry.getValue().getMessage());
-
final Throwable e = entry.getValue().getError();
-
if (e != null) {
-
e.printStackTrace();
-
}
-
}
-
}
-
try {
-
Thread.sleep(1000);
-
} catch (InterruptedException e) {
-
-
}
-
}
-
}
-
}
-
-
/*
-
console output:
-
database1: OK
-
database2: FAIL, error message: Can't ping database.
-
database1: FAIL, error message: Can't ping database.
-
database2: OK
-
database1: OK
-
database2: FAIL, error message: Can't ping database.
-
database1: FAIL, error message: Can't ping database.
-
database2: OK
-
database1: FAIL, error message: Can't ping database.
-
database2: FAIL, error message: Can't ping database.
-
database1: FAIL, error message: Can't ping database.
-
database2: FAIL, error message: Can't ping database.
-
database1: OK
-
database2: OK
-
database1: OK
-
database2: FAIL, error message: Can't ping database.
-
database1: FAIL, error message: Can't ping database.
-
database2: OK
-
database1: OK
-
database2: OK
-
database1: FAIL, error message: Can't ping database.
-
database2: OK
-
database1: OK
-
database2: OK
-
database1: OK
-
database2: OK
-
database1: OK
-
database2: FAIL, error message: Can't ping database.
-
database1: FAIL, error message: Can't ping database.
-
database2: FAIL, error message: Can't ping database.
-
-
*/
metrics提供了对Ehcache、Apache HttpClient、JDBI、Jersey、Jetty、Log4J、Logback、JVM等的集成,可以方便地将Metrics输出到Ganglia、Graphite中,供用户图形化展示。
阅读(6456) | 评论(0) | 转发(1) |