cinovo-redis-pingpong

cinovo-redis-pingpong sends PING commands to Redis using redis to check if the connection is alive by receiving a PONG within a certain time span.

Getting started

At first you must install and require the module.

npm install cinovo-redis-pingpong

Next you must require the module

var pingpong = require("cinovo-redis-pingpong");

Then you can watch a redis client

var client = require("redis").createClient(6379, "localhost");
...
pingpong.watch(client, {"interval": 5000, "maxTimespan": 2000, "maxMissesBeforeError": 5});
pingpong.on("error", function(err) {
	console.log("redis is not available");
});
...
pingpong.stop();

Done

Now your redis client is watched.

API

watch(client, cfg)

Watch a redis client.

• client: Instance of redid.createClient()...
• cfg: Object (optional)
  • interval: Number - Milli seconds between two PINGs (optional, default: 5000)
  • maxTimespan: Number - Milli seconds we wait for a PONG after the PING (optional, default: 2000)
  • maxMissesBeforeError: Number - If we counted $maxMissesBeforeError misses an error is emitted (optional, default: 5)

stop()

Stop the watcher.

Events

ping()

Is fired when the PING command is send.

pong(timespan)

Is fired when the PONG response arrived.

• timespan: Number - Time between PING and PONG in milli seconds

miss(misses, error)

Is fired if redis was missed.

• misses: Number . Number of misses so far
• error: Error that caused the miss

error(err)

Is fired when redis is no longer available.

• error: Error

stop()

If the watches was stopped.