zeit/redis-semaphore

Name: redis-semaphore

Owner: ZEIT

Description: Distributed mutex and semaphore based on Redis

Forked from: swarthy/redis-semaphore

Created: 2018-02-06 20:00:41.0

Updated: 2018-05-03 18:33:38.0

Pushed: 2018-03-19 18:27:16.0

Homepage: null

Size: 51

Language: JavaScript

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README

redis-semaphore

Mutex and Semaphore implementations based on Redis ready for distributed systems

Features

• Fail-safe (all actions performed by LUA scripts (atomic))

Usage

Mutex

new Mutex(redisClient, key [, { lockTimeout = 10000, acquireTimeout = 10000, retryInterval = 10, refreshInterval = acquireTimeout * 0.8 }])

• redisClient - required, configured redis client
• key - required, key for locking resource (final key in redis: mutex:<key>)
• timeouts optional
• lockTimeout - ms, time after mutex will be auto released (expired)
• acquireTimeout - ms, max timeout for .acquire() call
• retryInterval - ms, time between acquire attempts if resource locked
• refreshInterval - ms, auto-refresh interval

Example

t Mutex = require('redis-semaphore').Mutex
t redis = require('redis')

t redisClient = redis.createClient()

c function doSomething() {
nst mutex = new Mutex(redisClient, 'lockingResource')
ait mutex.acquire()
 critical code
ait mutex.release()

Semaphore

new Semaphore(redisClient, key, maxCount [, { lockTimeout = 10000, acquireTimeout = 10000, retryInterval = 10, refreshInterval = acquireTimeout * 0.8 }])

• redisClient - required, configured redis client
• key - required, key for locking resource (final key in redis: semaphore:<key>)
• maxCount - required, maximum simultaneously resource usage count
• timeouts optional
• lockTimeout - ms, time after semaphore will be auto released (expired)
• acquireTimeout - ms, max timeout for .acquire() call
• retryInterval - ms, time between acquire attempts if resource locked
• refreshInterval - ms, auto-refresh interval

Example

t Semaphore = require('redis-semaphore').Semaphore
t redis = require('redis')

t redisClient = redis.createClient()

c function doSomething() {
nst semaphore = new Semaphore(redisClient, 'lockingResource', 5)
ait semaphore.acquire()
 maximum 5 simultaneously executions
ait semaphore.release()

Installation

install --save redis-semaphore

 add redis-semaphore

License

MIT