Hi students !
I read this in the great MongoDB documentation :
Three-member Replica Set
For example, for a three-member replica set, some possible distributions of members include:
Two data centers: two members to Data Center 1 and one member to Data Center 2. If one of the members of the replica set is an arbiter, distribute the arbiter to Data Center 1 with a data-bearing member.
- If Data Center 1 goes down, the replica set becomes read-only.
- If Data Center 2 goes down, the replica set remains writeable as the members in Data Center 1 can hold an election.
If Data Center 1 goes down
Because of the quorum, the node on Data Center 2 can’t become a primary. So it remains a secondary. We can access this node by direct connection, but I thought that the replica set would be unavailable.
But here, the documentation says the replica set is read-only, so it is available.
How is it possible ?
Thank you for your answers !