Express.js Middleware to restrict duplicate requests for express.js.
If an API request arrives for the very first time it will lock it (using redis) and another request for same API with same request body arrive even before the response of previous API is sent, it will return an error in response for that second (duplicate) request
Important: Since this middleware relies on req.body to determine a duplicate request, always initialize this middleware after the request body has been parsed
Tip: To increase the throughput of this middleware, connect the redis client with redis server using unix sockets
npm install express-api-locker
var express = require('express')
var apiLock = require('express-api-locker')
var redisClient = require('redis').createClient()
var app = express()
app.use(apiLock(redisClient))
app.get('/', function(req, res) {
// We delay the response in order to mock the runtime of an actual API.
// Now, you can try and hit the same API before 2 secs and it should throw an error
setTimeout(() => {
return res.status(200).json('Hello, World!')
}, 2000)
})
app.listen(3000, function() {
console.log('Server listening at port 3000')
})| key | data type | description |
|---|---|---|
| ttl | number (default: 60000) | value (in millisecond) to expire the hashkey regardless of response was sent or not |
| silent | boolean (default: false) | if true, it will block the API execution in case of redis error |
| key_prefix | string (default: 'ApiLock') | this string will be appended as prefix to the key name in redis |