When the system receives a request to rebuild a structure during a structure alter operation, the success of the structure alter and the timing of the EEPLALTEREND event presentation to connectors depend on the following:

• If the structure rebuild request is received while a structure alter is in progress, the structure alter stops when the system performing the alter recognizes that rebuild is in progress. Whether the EEPLALTEREND event is presented depends on when in the rebuild process the recognition occurs.
• If the structure alter is stopped before the rebuild cleanup phase is entered, the EEPLALTEREND event is presented to the structure connectors. The EEPL contains the EEPLALTERENDREBLD bit, which is set to indicate that the alter ended due to a rebuild request. Depending on the timing, it is possible for the structure alter to complete before recognizing the request to stop due to a rebuild and the connectors will see only the EEPLALTEREND event indicating that the alter is complete.
• If the structure alter is not stopped before the rebuild cleanup phase, connectors will not be presented with an EEPLALTEREND event in the event exit pertaining to the “old” structure.
• If a rebuild stop is processed, XES completes the stop for structure alter that was requested when rebuild was started. The connectors receive the EEPLALTEREND event with the EEPLALTERENDREBLD bit set on to indicate that the alter ended due to a rebuild.