Node.js server: connect to redis database once? or at each request?

Question

I'm building a node.js server, with a simple authentication fetching uid and key in a redis database. Should I connect to the redis db once and for all upon running the server, like:

var http = require('http'),
    express = require('express');

var app = express();

var redis = require('redis'),
    redisclient = redis.createClient();

//... redis ready, error, end callback handlers here ...

app.get( '/connect/:uid/:key', function(req,res,next) {
   redisclient.hget(req.params.uid,req.params.key, function(err,rep) {
      // ... commands here...
      });
   });

or should I connect each time a connection request is done, like so:

var http = require('http'),
    express = require('express');

var app = express();

var redis = require('redis');

app.get( '/connect/:uid/:key', function(req,res,next) {
   var redisclient = redis.createClient();
   //... redis callback handlers here...
   redisclient.hget(req.params.uid,req.params.key, function(err,rep) {
      // ... commands here...
      });
   });

?

For now I'm talking about a limited number of connections, sparse in time, and no worries about efficiency optimisation.

Answer 1

I had the same confusion at some point but couldn't find any good answer. At the end I chose connecting just once to reduce lines of code. Redis mostly follows single threaded design so connection pooling won't be much help either.