node-redis-retry-strategy


A custom implementation of the node_redis retry_strategy function.

Sometimes, if the Redis server is down, you need to have clients that don't give up and try to reconnect.
"node-redis-retry-strategy" is a function that returns the node_redis retry_strategy function.
The strategy is: every wait_time try to connect for number_of_retry_attempts times (each time separated by delay_of_retry_attempts).
By default, every 5 minutes, try 5 times to reconnect (every attempt is separated by 500 ms). It retries forever.

* 2.0 breaking change: by default do not allow to start the service without a redis connection; to have the previous behaviour set allow_to_start_without_connection:true

Install

``bash

with npm

npm install node-redis-retry-strategy

or with yarn

yarn add node-redis-retry-strategy
`

Usage

`js
// redisClient.js file
var redis = require("redis");
var retryStrategy = require("node-redis-retry-strategy");

var client = redis.createClient({
host: "127.0.0.1",
port: 6379,
retry_strategy: retryStrategy()
});

module.exports = client;
`
`js
// index.js file
var redisClient = require("redisClient.js");

redisClient.on("connect", function () {
console.log("connected!");
});
redisClient.on("end", function () {
console.log("redis connection has closed");
});
redisClient.on("reconnecting", function (o) {
console.log("redis client reconnecting", o.attempt, o.delay);
});
`


Options


It accepts options object as a parameter with 4 possible keys:
#### allow_to_start_without_connection type boolean
Default: false
2 possible scenarios:
- false if there is no connection when the service starts, end reconnecting throwing an error and flush all commands
- true allow to start the service without a redis connection
`js
var redis = require("redis");
var retryStrategy = require("node-redis-retry-strategy");

var client = redis.createClient({
host: "127.0.0.1",
port: 6379,
retry_strategy: retryStrategy({
allow_to_start_without_connection: true
})
});

module.exports = client;
`
#### number_of_retry_attempts type number ms
Default: 5
The number of attempts separated by the delay_of_retry_attempts. If set to 0, it ends reconnecting with the built in error.
`js
var redis = require("redis");
var retryStrategy = require("node-redis-retry-strategy");

var client = redis.createClient({
host: "127.0.0.1",
port: 6379,
retry_strategy: retryStrategy({
number_of_retry_attempts: 7
})
});

module.exports = client;
`
#### delay_of_retry_attempts type number ms
Default: 500
The delay between each retry attempts.
`js
var redis = require("redis");
var retryStrategy = require("node-redis-retry-strategy");

var client = redis.createClient({
host: "127.0.0.1",
port: 6379,
retry_strategy: retryStrategy({
delay_of_retry_attempts: 1000
})
});

module.exports = client;
`
#### wait_time type number ms
Default: 300000 (5 min)
How long stop retrying to connect.
`js
var redis = require("redis");
var retryStrategy = require("node-redis-retry-strategy");

var client = redis.createClient({
host: "127.0.0.1",
port: 6379,
retry_strategy: retryStrategy({
wait_time: 600000
})
});

module.exports = client;
``

License

MIT