(Replication mode)

Scenario 1 : If the main-primary were to go down in replication mode.

Switching Main and Secondary Primary Servers

In the unforeseen event where the main-primary server goes down the second-primary will take over and become the primary server and ensure that the system still runs. Once we recover the main-primary server we can then restart all the services on the main-primary server, to do that run the following command.

Run as root user

systemctl restart nmis9d opchartsd opeventsd omkd ophad

To switch from the Secondary Primary back to the Main-Primary so the main-primary is the master again follow these steps:

1. Connect to MongoDB on the master server in this case the (second-primary):

   mongosh --username opUserRW --password op42flow42 admin

2. Update member priorities:

   cfg = rs.conf() cfg.members[0].priority = 0.6 cfg.members[1].priority = 0.5 rs.reconfig(cfg)