Recovering a high availability configuration

After failing over to a GitHub Enterprise Server appliance, you should regain redundancy as soon as possible rather than rely on a single appliance.

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About recovery for a high availability configuration

You can use the former primary appliance as the new replica appliance if the failover was planned or was not related to the health of the appliance. If the failover was related to an issue with the primary appliance, you may prefer to create a new replica appliance. For more information, see "Creating a high availability replica."

Warning

You must enable maintenance mode before configuring a former primary appliance as a new replica. If you do not enable maintenance mode, you will cause a production outage.

Configuring a former primary appliance as a new replica

  1. Connect to the former primary appliance's IP address using SSH.

    ssh -p 122 admin@ FORMER_PRIMARY_IP

  2. Enable maintenance mode on the former primary appliance. For more information, see "Enabling and scheduling maintenance mode."

  3. On the former primary appliance, run ghe-repl-setup with the IP address of the former replica.

    ghe-repl-setup FORMER_REPLICA_IP

  4. To add the public key to the list of authorized keys on the primary appliance, browse to https://PRIMARY-HOSTNAME/setup/settings and add the key you copied from the replica to the list.

  5. To verify the connection to the new primary and enable replica mode for the new replica, run ghe-repl-setup again.

    ghe-repl-setup FORMER_REPLICA_IP

  6. To start replication of the datastores, use the ghe-repl-start command.

    ghe-repl-start

    Warning

    ghe-repl-start causes a brief outage on the primary server, during which users may see internal server errors. To provide a friendlier message, run ghe-maintenance -s on the primary node before running ghe-repl-start on the replica node to put the appliance in maintenance mode. Once replication starts, disable maintenance mode with ghe-maintenance -u. Git replication will not progress while the primary node is in maintenance mode.