eljam/circuit-breaker

A php Circuit Breaker

Circuit Breaker

Circuit breaker is heavily used in microservice architecture to find issues between microservices calls., _(*1)

The main idea is to protect your code from making unnecessary call if the microservice you call is down., _(*2)

Features

• Automatic update. (i.e you don't have to manually add success or failure method like other library)
• Return result from the protected function
• Retry timeout
• Exclude some exceptions from being throwned, return null instead.
• Multiprocess updates handled with a cache library. Supports all cache provider from (doctrine cache library).
• Event powered

, _(*3)

Full Example:, _(*4)

<?php

use Doctrine\Common\Cache\FilesystemCache;
use Eljam\CircuitBreaker\Breaker;
use Eljam\CircuitBreaker\Event\CircuitEvents;
use Symfony\Component\EventDispatcher\Event;

require_once __DIR__.'/vendor/autoload.php';

$fileCache  = new FilesystemCache('./store', 'txt');

//Create a circuit for github api with a file cache and we want to exclude all exception.
$breaker = new Breaker('github_api', ['ignore_exceptions' => true], $fileCache);

$breaker->addListener(CircuitEvents::SUCCESS, function (Event $event) {
    $circuit = $event->getCircuit();
    echo "Success:".$circuit->getFailures()."\n";
});

$breaker->addListener(CircuitEvents::FAILURE, function (Event $event) {
    $circuit = $event->getCircuit();
    echo "Increment failure:".$circuit->getFailures()."\n";
});

$breaker->addListener(CircuitEvents::OPEN, function (Event $event) {
    $circuit = $event->getCircuit();
    echo sprintf("circuit %s is open \n", $circuit->getName());
});

$breaker->addListener(CircuitEvents::CLOSED, function (Event $event) {
    $circuit = $event->getCircuit();
    echo sprintf("circuit %s is closed \n", $circuit->getName());
});

$breaker->addListener(CircuitEvents::HALF_OPEN, function (Event $event) {
    $circuit = $event->getCircuit();
    echo sprintf("circuit %s is half-open \n", $circuit->getName());
});

$result = $breaker->protect(function () {
    throw new \Exception("An error as occured");
    // return 'ok';
});