Question

I want to set up MongoDb on a single server, and I’ve been searching around to make sure I do it right. I have gleaned a few basics on security so far:

1. Enable authentication (http://www.mongodb.org/display/DOCS/Security+and+Authentication – not enabled by default?)
2. Only allow localhost connections
3. In PHP, be sure to cast GET and POST parameters to strings to avoid injection attacks (http://www.php.net/manual/en/mongo.security.php)

I’ve also picked up one thing about reliability.

1. You used to have use sharding on multiple boxes, but now you can just enable Journaling? (http://stackoverflow.com/questions/3487456/mongodb-are-reliability-issues-significant-still)

Is that the end of the story? Enable Authentication and Journaling and you are good to go a single server?

Thanks!

Answer 1

If you are running on a single server, then you should definitely have journaling enabled. On 2.0, this is the default for 64-bit builds; on 32-bit builds or older releases (the 1.8.x series) you can enable it with the --journal command-line flag or config file option. Be aware that using journaling will cause MongoDB to use double the memory it normally would, which is mostly an issue on 32-bit machines (since memory there is constrained to around 2GB ordinarily, with journaling it would be effectively halved).

Authentication can help, but the best security measures are to ensure that only machines you control can talk to MongoDB. You can do this with the --bind_ip command-line flag or config file option. You should also set up a firewall (iptables or similar) as an extra measure.

As for injection attacks, you should mostly be safe, so long as you don’t blindly convert JSON (or similar structures) into PHP assocs and pass them directly to the MongoDB methods. If you construct the assoc yourself, by processing the $POST or $GET values, you should be safe.