Specifications

14 – Configuring and Monitoring a Redundant Server System
328 R400
What To Do If the Servers Lose Synchronization
Because PlantScape is a high availability system, it is very important to recognize
quickly if the servers lose synchronization (that is, stop running in redundant
mode).
The servers may lose synchronization if:
• The primary server suffers a hardware/software failure
• The backup server suffers a hardware/software failure
• The communications link(s) between the servers is broken
If there is a redundancy problem, urgent alarms are generated. You should
immediately call up the Redundancy Status display to confirm whether
synchronization has been lost and to determine which server is running as the
primary. (The Server Redundancy Status display is automatically called up if you
double-click a redundancy alarm.)
Once you have confirmed that there is a problem with one of the servers or the
communications link between the servers, the problem should be rectified as
soon as possible and the servers put back into redundant mode.
If the Primary Server Fails
If the primary server fails, your PlantScape system will fail over and the backup
server becomes the primary. In this case you should:
1 Determine the cause of the problem on the primary server and rectify it. (If
there was a hardware fault, some part of the hardware may need to be
replaced.)
2 Reconfigure or re-verify (depending on the cause of the problem) the
redundancy configuration on the primary server. (Refer to “Completing the
TCP/IP Configuration of the Servers” on page 306.)
3 Resynchronize the primary and backup servers. In this case the contents of
the PlantScape database on the backup server (which is running as the
primary) are transferred to the primary server.
4 Manually fail over to the primary server (once the servers are synchronized).
The primary server then runs as primary again.
5 Resynchronize the primary and backup servers.
plscpcg.book Page 328 Monday, May 28, 2001 10:11 AM