Throttler

Load balancer between nodes.

Installation

You can install the latest version via Composer:

composer require orangesoft/throttler

This package requires PHP 8.1 or later.

Quick usage

Configure Orangesoft\Throttler\WeightedRoundRobinThrottler::class as below and set weight for each node if you are using weighted strategy:

<?php
use Orangesoft\Throttler\Counter\InMemoryCounter;
use Orangesoft\Throttler\Collection\NodeInterface;
use Orangesoft\Throttler\Collection\Node;
use Orangesoft\Throttler\WeightedRoundRobinThrottler;
$throttler = new WeightedRoundRobinThrottler(
    new InMemoryCounter(),
);
$collection = new InMemoryCollection([
    new Node('192.168.0.1', 5),
    new Node('192.168.0.2', 1),
    new Node('192.168.0.3', 1),
]);
while (true) {
    /** @var NodeInterface $node */
    $node = $throttler->pick($collection);
    // ...
}

As a result, the throttler will go through all the nodes and return the appropriate one according to the chosen strategy as shown below:

+---------+-------------+
| request | node        |
+---------+-------------+
|       1 | 192.168.0.1 |
|       2 | 192.168.0.1 |
|       3 | 192.168.0.1 |
|       4 | 192.168.0.1 |
|       5 | 192.168.0.1 |
|       6 | 192.168.0.2 |
|       7 | 192.168.0.3 |
|       n | etc.        |
+---------+-------------+

The following throttlers are available:

Benchmarks

Run composer phpbench to check out benchmarks:

+-------------------------------+------+-----+----------+----------+----------+---------+
| benchmark                     | revs | its | mean     | best     | worst    | stdev   |
+-------------------------------+------+-----+----------+----------+----------+---------+
| RandomBench                   | 1000 | 5   | 4.002μs  | 3.880μs  | 4.097μs  | 0.073μs |
| WeightedRandomBench           | 1000 | 5   | 11.660μs | 11.533μs | 11.797μs | 0.094μs |
| FrequencyRandomBench          | 1000 | 5   | 6.074μs  | 5.924μs  | 6.242μs  | 0.139μs |
| RoundRobinBench               | 1000 | 5   | 4.060μs  | 3.888μs  | 4.363μs  | 0.171μs |
| WeightedRoundRobinBench       | 1000 | 5   | 10.778μs | 10.655μs | 10.919μs | 0.115μs |
| SmoothWeightedRoundRobinBench | 1000 | 5   | 6.888μs  | 6.707μs  | 7.102μs  | 0.130μs |
+-------------------------------+------+-----+----------+----------+----------+---------+

The report is based on measuring the speed. Check best column to find out which strategy is the fastest.

Documentation

Read more about load balancing on Sam Rose’s blog.