My test system (due to lack of resources) has a dual mongodb replicaset. There is no arbiter.
During some system changes one of the servers got put out of action and will not be coming back. This server happened to host the primary mongo node. This left the only other member of the set as a secondary.
I know I should have had at least three nodes for the cluster (our prod setup does).
Is there a way I can make the primary that is now offline to step down? I haven't been able to change any of the rs.conf() settings because the only working node is secondary. starting an arbiter doesn't seem to work because I cannot add it to the replset as the primary is down.
Has anyone encountered this before and managed to resolve it?
To recap:
SERVER A (PRIMARY) - OFFLINE
SERVER B (SECONDARY) - ONLINE
A + B = REPLSET
Any help would be greatly appreciated.
The mongodb website has documentation for what to do (in an emergency only) when you need to reconfigure a replica set when members are down. This sounds like the situation you are in.
Basically, if you're on version >= 2.0, and it's an emergency, you can add force: true to the replica set configuration command.
来源：https://stackoverflow.com/questions/9632156/promote-secondary-to-primary-from-secondary-node