Java Code Run Insight Library Metrics__java

Metrics is a Java library that can provide you with unmatched code-run insight.
It was developed by Yammer to detect the health of back-end services on the JVM. Metrics provides a powerful toolset for measuring the behavior of key components in your production environment.

Metrics provides a common set of modular libraries for support such as Guice,jetty,log4j,apache httpclient,ehcache,logback,spring, Also provides comparisons such as ganglia and graphite backend reports.

Website of the project: http://metrics.dropwizard.io/

Metrics has five major components

1:counter

Record execution times

2:gauge

Get a value

3:meter

The rate used to calculate events

4:histogram

You can provide statistical data for a data flow. In addition to the maximum, the minimum, the average, it can also measure the median (median), the percentages such as xx% such quantile data

5:timer

Used to measure the rate and time at which a piece of code is invoked. Equal to Meter+hitogram, not only TPS, but also execution time.

Here is the code example

First join the dependency

<dependency>  
    <groupId>io.dropwizard.metrics</groupId>  
    <artifactid>metrics-core </artifactId>  
    <version>3.1.2</version>  
</dependency>  

Com.codahale.metrics.MetricRegistry is the core of the metrics, which is first preserved with a constant

Package com.lala.core;  
  
Import Com.codahale.metrics.MetricRegistry;  
  
public class Metricconstant   
{public  
    static metricregistry REGISTER = new Metricregistry ();  
}  

It also says that metrics supports a lot of output, JMX, log4j, Jetty, httpclient, and so on. I'm going to output it directly to the console.

Package com.lala.core;  
  
Import Java.util.concurrent.TimeUnit;  
Import Com.codahale.metrics.ConsoleReporter;  
/** 
 * Console printout/public  
class Myconsolereport {public  
    static void Startreport ()  
    {  
        final Consolereporter reporter = Consolereporter.forregistry (metricconstant.register)  
                . Convertratesto ( Timeunit.seconds)  
                . Convertdurationsto (timeunit.seconds)  
                . Build ();  
        Perform one second  
        reporter.start (1, timeunit.seconds);  
    }  
  

First of all, come to a basic public class

Package com.lala.core;  
  
Import Java.util.concurrent.TimeUnit;  
Import Com.codahale.metrics.MetricRegistry;  
  
public class Base   
{  
    protected static metricregistry metric = Metricconstant.register;  
    protected static void Secondsleep (Long value)  
    {  
        try  
        {  
            TimeUnit.SECONDS.sleep (value);  
        } catch ( Interruptedexception e)  
        {  
            e.printstacktrace ();  
        }  
    }  
    protected static void Millisecondsleep (Long value)  
    {  
        try  
        {  
            TimeUnit.MILLISECONDS.sleep (value);  
        } catch (interruptedexception e)  
        {  
            e.printstacktrace ();  
        }  
    }  
}  

Next, let's demonstrate the basic usage of the five major components

One: Counter

[Java]  View plain  copy package com.lala.demo;      import java.util.random;       import com.codahale.metrics.counter;   import com.lala.core.base;    import com.lala.core.myconsolereport;     /**   *  record execution times    */   public class countertest extends base   {       final static counter exec = metric.counter (" Com.pp.counter.invoke ");       public static void main (String[)  args)        {            Myconsolereport.startreport ();           new thread (()- >{               for (int i=1;i <=3;i++)    &NBsp;           {                    exec.inc ();                    millisecondsleep (new  Random (). Nextint () *2);                          &nbsp}). Start ();            secondsleep (3);       }  }  
The output is as follows:

15-11-22 20:38:29 ==============================================================


--Counters--------------------------------------------------------------------
Com.pp.counter.invoke
Count = 3

Two: Gauge

[Java] view plain copy package Com.lala.demo;