Establishing client connection to CQS during failed client takeover

When the client (such as IMS) supports XRF takeover capability, one client must take over the work for a failed client. The CQS connected to this failed client might not be active. Therefore, during the takeover process, the client taking over work from a failed client must connect to a different CQS and indicate that it is taking over work from another client.

At this point, CQS must perform a process similar to CQS restart, using the log records from the CQS connected to the failed client. Normally, CQS failed client connection restart (warm start) is automatic and you do not need to take any action.

During a failed client connection, CQS reads the log token from the structure for the CQS connected to the failed client.

If CQS finds the log token, CQS performs warm start processing for the failed client.
If CQS does not find the log token, CQS issues WTOR CQS0033A. At this point, you can do one of the following:
- Cold start the client connection.
- Reject the client connection request.
- Specify a new log token.

Recommendation: If a CQS does not accept a log token during failed client connection restart, cold start the connection. If multiple CQSs are running, one CQS structure checkpoint might purge the log records for another CQS that previously failed and was not restarted.