Connection pooling

pool-demo.js

//Problem: In node.js, one must pool redis db connections, otherwise they die

//Solution: Use generic-pool
pool = poolModule.Pool({
    name: 'redis',
    create: function (callback) {
        var redisClient = redis.createClient();
        callback(null, redisClient);
    },
    destroy  : function (client) {
        client.quit();
    },
    max: 10,
    min: 0,
    idleTimeoutMillis : 4000,
    log : false
});
//Using the pool
pool.acquire(function (err, client){
    client.hgetall("hash", function (err, data) {
        pool.release(client);
        //do something with data
    });
});

//Problem 2: Hide connection pooling from app code

//Solution - use pool.pooled
var pooledRedis = {
    hgetall: pool.pooled(function (client, hashName, cb) {
        client.hgetall(hashName, cb);
    }),
    lrange: pool.pooled(function (client, key, start, length, cb) {
        client.lrange(key, start, length, cb);
    })
};

//Problem 3: Duplication, ugly
//Solution - some argument slicin'

var methods = ["hgetall", "lrange"];
methods.forEach(function (funcName) {
    pooledRedis[funcName] = pool.pooled(function (client) {
        var args = Array.prototype.slice.call(arguments, 1, arguments.length);
        client[funcName].apply(client, args);
    });
});

Why are you pooling redis? the client has an auto reconnect option... also make sure you use the optional hiredis bindings

@sugendran You are correct, pooling was a red herring after all. The problem was connect-redis module(session persistence). It has its own client and I had to add an error handler to that so that redis connection loss doesn't bring the app down. Let's see if http://runheat.jit.su survives for a while.

Hmm alright, might need to fork connect-redis and add ability to inject a pool. Seems like the connection eventually (after 30 minutes) enters a bad state that it doesn't recover from - [Error: Redis connection to failed - read ETIMEDOUT].

Do you have an update on this? I suffer from same issue

I too am having this issue; it's odd I seemed to have the issue using my own redis server on Joyent, but not using RedisToGo, which makes me wonder if there's something in the Redis configuration that can resolve it.

I seem to be having this issue too. After about 20 minutes my entire app/server becomes unresponsive. After a slightly variable but usually large amount of time I get [Redis connection to failed - read ETIMEDOUT] and it starts working again.

Anyone have any more information about this?