High Availability Guide : Watchdog sample : Failure situations and Watchdog actions : Communication links between the Watchdog and Secondary, and between the Primary and Secondary, are down
  
Communication links between the Watchdog and Secondary, and between the Primary and Secondary, are down
Scenario
The connection between the Watchdog and the Secondary server, and the connection between the Primary server and Secondary, server are broken.
Remedy
The Primary server can continue operations even when its links to the Secondary server and the Watchdog are down. Switch the Primary server to the PRIMARY ALONE state, if it is not already in PRIMARY ALONE state. Later, when the Secondary is up again, synchronize it with the Primary.
1 Server2 sees its role as Secondary Alone, but the Watchdog cannot see Server2 and therefore believes Server2 is unavailable.
Watchdog instructs Server 1:
HSB SET PRIMARY ALONE
2 After the connections to secondary are fixed, Watchdog instructs Server 1: HSB NETCOPY HSB CONNECT
3 If the transaction log fills up, you may have to switch the PRIMARY ALONE server to STANDALONE. In that case, you will also need to execute HSB NETCOPY before you reconnect the servers. If the transaction log does not fill up, then you must skip the NETCOPY command.
Symptoms
The Watchdog poll fails at the Secondary; the Primary server has no Secondary connected and switches to state PRIMARY UNCERTAIN or PRIMARY ALONE.
How to recover when communication links between the Watchdog and Secondary, and between the Primary and Secondary, are down
About this task
To recover from the scenario where the connection between the Watchdog and the Secondary server, and the connection between the Primary server and Secondary server are broken:
Procedure
1 Try to fix the connections.
2 After the connections are fixed, check the state of the Primary server using the command
ADMIN COMMAND 'hotstandby state'.
3 If the state of the Primary is STANDALONE:
a Ensure that both servers are running.
b Set the state of the Primary server to PRIMARY ALONE using command:
ADMIN COMMAND 'hotstandby set primary alone';
c Copy the database from the Primary to the secondary using command:
ADMIN COMMAND 'hotstandby netcopy';
Read Synchronizing primary and secondary servers for details.
4 Reconnect the Primary to the Secondary using the command:
ADMIN COMMAND 'hotstandby connect';
Further scenarios where the communication links between the Watchdog and Secondary, and between the Primary and Secondary are down
If an application receives error message 10047 or 14537 from the Primary:
Try to connect to the Secondary to check if it switched to be Primary.
If the Secondary is not switched as the new Primary, re-execute the transaction with the original Primary in PRIMARY ALONE state.
See also
Failure situations and Watchdog actions