http://docs.mongodb.org/manual/reference/server-status/
- mongo_ops : operations/second
- mongo_mem : mapped, virtual and resident memory usage
- mongo_btree : btree access/misses/etc...
- mongo_conn : current connections
- mongo_lock : write lock info
- mongo_primary : Current primary member ID
- mongo_replication : Seconds behind master on replSet
- simplejson or python >= 2.6
- MongoDB 1.4+
You can set HOST and PORT for the REST interface in the plugin config. If you don't, they will default to 127.0.0.1 and 28017 - that should work for local checks on a default install.