Subsystem Control Point (SCP) Management Programming Manual

Event Messages
Subsystem Control Point (SCP) Management Programming Manual—520619-001
6-5
Event Messages and Programmatic Error Recovery
Event Messages and Programmatic Error Recovery
Event messages are useful for programmatic error diagnosis and recovery. They can
help you identify the root cause of a problem and respond appropriately. For example, if
an SCP process returns a timeout error in response to a command, an associated event
message might reveal that lack of internal table space prevented the SCP process from
processing additional command messages. The additional information revealed by the
event message makes an appropriate response possible.
Your application can include a diagnostic routine that uses event messages to determine:
•
Whether an SCP process should be restarted. A system message sent to the SCP
process creator or a file-system error 201 indicates that the SCP process has been
stopped. An event message can reveal the cause as a system-resource problem, an
SCP process-resource problem, or an SCP program-code problem.
•
Whether a command message should be issued again to another SCP process when
the subsystem configuration can potentially contain multiple SCP processes. Event
messages might show that the SCP process is trying to process too many command
messages.
•
Whether a command message has been executed and processed again because of a
takeover by the backup SCP process. When a command message is processed again,
an error can be produced. For example, if a STOP command is successful, executing
the same command again produces an error indicating that an object reporting the
STOPPED summary state cannot be stopped. An event message can indicate that an
SCP backup process has taken over.
•
Whether command-message processing should be temporarily halted because the
SCP process is no longer able to process command messages.
Security Violation: PAID: ..., Cmd: ..., For: ... SECURITY-VIOL 35
SIGNALTIMEOUT for backup failed; no
backup
BKP-SIGNALTIMEOUT-ERR 25
SIGNALTIMEOUT for deletedelay failed DEL-SIGNALTIMEOUT-ERR 17
SIGNALTIMEOUT for shutdown failed SHUT-SIGNALTIMEOUT-ER 1
State changed from ... to ... SUMSTATE-CHANGE 33
Subserver open table full SCB-FULL 23
SWITCH command failed SWITCH-CMD-FAIL 8
Unrecoverable SPI error: ... SPI-ERR 11
USESEGMENT failed USESEGMENT-ERR 3
Table 6-3. ZSCP Events Generated by SCP Processes, by Message
Text (page 2 of 2)
Message Text Name (ZSCP-EVT-...) Number