Metrics Crawler

A little library with zero dependencies to crawl metrics and store during a certain window. The library provides an utility to monitor certain code segments and measure with minimum performance some estatistics:

Number of measures taken
Last measure
Maximum measure
Minimum measure
Average measure
Last measure occurrence

And this measures can be:

Double
Long
Duration (elapsed time)

All sensors implements Autocloseable in order to reduce boilerplate when taking measures. The library allows create metric names manually or tracking your sensor stack if you are using imperative programming (As the library uses ThreadLocal to stack the sensors if you use multithreading you can have unexpected results)

Motivation

When you have performance problems in production environment and don’t know where look, the only way is to have measures directly from real, using sensors allows to identify the bottlenecks in production

Quick start

(Please read our Javadoc for further information)

First of all include the Jar file in your compile and execution classpath.

Maven
```
<dependency>
    <groupId>org.bytemechanics</groupId>
    <artifactId>metrics-crawler</artifactId>
    <version>X.X.X</version>
</dependency>
```
Graddle
```
dependencies {
    compile 'org.bytemechanics:metrics-crawler:X.X.X'
}
```
1.1. Optionally register external MetricService supplier at application startup, take in account that expects this supplier always return the same instance (only necessary if you want to use a singleton distinct from the default one)
```
AbstractSensor.registerMetricsServiceSupplier([your supplier]);
```

Start measuring

2.1. Option1: With manual naming

import org.bytemechanics.metrics.crawler.sensors.DoubleSensor;
import org.bytemechanics.metrics.crawler.sensors.LongSensor;
import org.bytemechanics.metrics.crawler.sensors.DurationSensor;
(...)
try(DoubleSensor sensor1=DoubleSensor.get("myName")){
	sensor1=2.0d;
	(...)
}
(...)
try(LongSensor sensor1=LongSensor.get("my{}Name{}","long",1)){
	sensor1=2l;
	(...)
	try(LongSensor sensor2=LongSensor.get("my{}Name{}.my{}Name{}","long",1,"long",2)){
		sensor2=5l;
		(...)
	}
}
(...)
try(DurationSensor sensor1=DurationSensor.get("{}myName{}","duration","sensor")){
	(...)
}

2.2. Option2: With stack naming (the same result)

import org.bytemechanics.metrics.crawler.sensors.stack.DoubleStackSensor;
import org.bytemechanics.metrics.crawler.sensors.stack.LongStackSensor;
import org.bytemechanics.metrics.crawler.sensors.stack.DurationStackSensor;
(...)
try(DoubleStackSensor sensor1=DoubleStackSensor.get("myName")){
	sensor1=2.0d;
	(...)
}
(...)
try(LongStackSensor sensor1=LongStackSensor.get("my{}Name{}","long",1)){
	sensor1=2l;
	(...)
	try(LongStackSensor sensor2=LongStackSensor.get("my{}Name{}","long",2)){
		sensor2=5l;
		(...)
	}
}
(...)
try(DurationStackSensor sensor1=DurationStackSensor.get("{}myName{}","duration","sensor")){
	(...)
}