When you start the master server, you can specify the replication strategy using the -defaultReplication flag. This flag defines how data is replicated across the cluster. Here's how you can set it:
- 000: no replication
- 001: replicate once on the same rack
- 010: replicate once on a different rack, but same data center
- 100: replicate once on a different data center
- 200: replicate twice on two different data center
- 110: replicate once on a different rack, and once on a different data center