MongoDB is known for its easy and near zeroconf setup. But when it comes to the point, to setup a sharded cluster with replication, things can get complex. Therefore I'd like to provide a configuration tooling to setup such a cluster with only a couple of simple commands.
My first headache was the router/config-server thing. I didn't get, that it's necessary to setup first 1 or 3 config-servers, each a tuple of mongod --configsrv and mongos. These do not store any of your applications data, they only coordinate sharding.
The rest of the part is quite easy and straight-forward. Setup as much shards and replica-sets as you need. Well, a 3 x 3 cluster for testing and playing arround is quite nice. But now you get 3 config servers (3 x mongod and 3 x mongos) , 9 shards so you get 15 instances and 15 config files with appropriate init.d/start/stop scripts. And you have to deploy that stuff.
This led me to create a simple set of scripts to create such a configuration. You easily setup your settings, which describe your environment and perform following steps:
- Create mongo config
- Deploy it to the servers (via SSH)
- Perform finalization (usually you do not perform [email protected], instead you su or sudo it) and start the instances
- Invoke the create replicas script (generated)
- Invoke the setup sharding script (generated)
- That's it.
You can find that code at GitHub: https://github.com/mp911de/mongo-shardgen
And in case you got stuck: following links helped me to get through: