Is Node Stateful? Can Node maintain variables in memory

Question

Is Node stateful?

If I want to build an index to keep in memory, will it persist throughout different connections? I'm just wondering if this is possible. For example we have a server in java that maintains a hashmap in memory to speed up certain search queries. It modifies it as things come in. Would this be possible in Node?

Thanks.

Answer 1

Absolutely. Here's a dead-simple example of what I think you're looking for (modified sample code from http://nodejs.org):

var http = require('http');
var foo = 0;
http.createServer(function (req, res) {
  foo += 1;
  res.writeHead(200, {'Content-Type': 'text/plain'});
  res.end('You are foo number ' + foo + '\n');
}).listen(1337, '127.0.0.1');
console.log('Server running at http://127.0.0.1:1337/');

Note that this sort of thing often isn't done except for the most transient sort of data. If you something a little more persistent, look at using something like redis