Active - Active or 2-way replication is very similar to 1-way replication.
It can be viewed as 2 x 1-way replication, with an outer (1-way) loop and an inner (1-way) loop as seen in the following diagram:
The differences between 1-way replication and 2-way replication are:
- There is a Mine and Apply processes running on each server. With 1-way replication there is only an Apply OR a Mine process running.
- Changes that are mined on the source server and then applied on the target server are not mined again on the target server. This prevents the feedback loop.
- The Mine and Apply processes are paired together. So in a typical 2-way replication there are the following 2-pairs:
- MINE - APPLY
- MINE1 - APPLY1
2-way replication can be configured through the setup wizard.