What will be the best way to reuse a CouchBase conneciton - node.js

Question

I am using the following code for connecting the CouchBase
couchbase.connect(config.CouchBaseConnector, function (err, CouchBaseDB) {
if (err) {
throw (err)
}
CouchBaseDB.set(keyPush, docPush, function (err, meta) {
if (err) { console.log(err); }
});
}
But its creating multiple number of connection.
Can someone help me out to fix the issue. Basically I want to do something like connection pool and keep re-using.
I came across a doc from CouchBase regarding the same. But not able to figure it out how exactly it works and the steps to deploy the same on windows 7 64-bit version.
Update:
I think moxi-server is not released for Windows OS as of now.

Answer 1

The Couchbase Node SDK is a Connection Pool itself. It is responsible of managing connection to the cluster, be alerted about any change in the server topology (add/remove/failed nodes)
This is why most of the time you put your code in a global callback method and reuse the connection
var express = require('express'),
driver = require('couchbase'),
routes = require('./routes');
dbConfiguration = {
"hosts": ["my-couchbase-server:8091"],
"bucket": "bucket"
}
driver.connect(dbConfiguration, function(err, cb) {
if (err) {
throw (err)
}
// put your application logic here
});
If you want to use a global variable you need to wait for the callback and be sure that the connection is established before using it.

Answer 2

I found the following code is working for me.
Please anyone has better solution please post it, I always welcome that.
GLOBAL.CouchBaseDBConnection = undefined;
function OpenCouchBase(callback) {
if (CouchBaseDBConnection == undefined) {
couchbase.connect(config.CouchBaseConnector, function (err, couchbaseOpenCon) {
if (err)
return console.log("Failed to connect to the CouchBase");
else {
CouchBaseDBConnection = couchbaseOpenCon
callback(null, couchbaseOpenCon);
}
});
}
else { callback(null, CouchBaseDBConnection); }
};
module.exports.OpenPoolCouchBase = OpenCouchBase;

Answer 3

You can use generic resource pool module for Node: node-pool
It is generic pool, so you can adapt it for your needs.
EDIT:
Here is example code:
var poolModule = require('generic-pool');
var pool = poolModule.Pool({
name : 'couch',
create : function(callback) {
couchbase.connect(config.CouchBaseConnector, function (err, couchbaseOpenCon) {
if (err)
return console.log("Failed to connect to the CouchBase");
else {
CouchBaseDBConnection = couchbaseOpenCon
callback(null, couchbaseOpenCon);
}
});
},
destroy : function(client) { client.end(); },
max : 10,
// specifies how long a resource can stay idle in pool before being removed
idleTimeoutMillis : 30000,
// if true, logs via console.log - can also be a function
log : true
});
// acquire connection - callback function is called once a resource becomes available
pool.acquire(function(err, client) {
if (err) {
// handle error - this is generally the err from your
// factory.create function
}
else {
console.log("do whatever you want with the client ...");
pool.release(client);
});
}
});