问题
I have two MongoDB running in two different servers connected via LAN. I want to replicate records from few collections from server 1 to collections in server 2. Is there any way to do it. Below is the pictorial representation of what I want to achieve.
Following are the methods I consider using.
- MongoDB replication - But it replicates all collections. Is selective replication possible in MongoDB ??
- Oplog watcher APIs - Please suggest some reliable java APIs
Is there any other way to do this ? and what is the best way of doing it ?
回答1:
MongoDB does not yet support selective replication and it sounds as though you are not actually looking for selective replication but more for selective copying since replication ensures certain rules of using that server.
I am not sure what you mean by a oplog watcher API but it is easy enough to read the oplog over time by just querying it:
> use local
> db.oplog.rs.find()
( http://docs.mongodb.org/manual/reference/local-database/ )
and then storing the latest timestamp of the record you have copied within a script you make.
You can also use a tailable cursor here on the oplog to effectiely listen (pub/sub) to changes and copy them over to your other server.
来源：https://stackoverflow.com/questions/22218175/selective-replication-in-mongodb