Emulate a Failover Situation

To demonstrate what would happen if the primary server were to fail, you can kill off its process, which should initiate the failover process.

On the Enterprise Server Administration home page, click Details in the Status column for the primary server.
Click ES Monitor & Control.
Click SEPs.
The SEPs information appears.
Make a note of the process ID for the ES Manager.
On UNIX, type the following:
```
kill <process ID>
```
This kills off the primary server and automatically assigns the role of primary to one of the standby servers.
On the Enterprise Server Administration home page, click Details in the Status column of each standby server, then click ES Monitor & Control. You will notice that one of the standby servers is now displaying a status of HA VSAM Primary.
To confirm the group is still operating as expected, from the Enterprise Developer command prompt, type:
```
cobrun runner.int
```
This reruns the previous program; if you examine the system directories for each of the remaining servers, you'll notice that the timestamp for file.dat has been updated, confirming that the file is still being replicated within the group.
Restart the old primary server. When it has restarted, it attempts t he two-stage recovery process (as detailed in The Failover and Recovery Process). If that is successful, the server re-joins the group as a standby server.
On the Enterprise Server Administration home page, click Details in the Status column of that server, then click ES Monitor & Control. You will notice that it is displaying a status of HA VSAM Hot Standby.

This concludes the walkthrough. You can now stop each server to close the group.

Note: If you have closed down cleanly and plan to restart the group, ensure that you delete the logtrans.tlog file from the system directory on each server in the group before it is started. You do not need to delete logtrans.tlog if the group is still running and you are attempting to add a server back into the group.