The server issues various messages during execution, some of which might indicate that serious problems are developing, for example that the coupling facility structure is becoming full. It is important to understand the types of messages that the server issues and to ensure that system status messages are monitored for possible problems.
Messages that are issued by the server code itself start with the five-letter server prefix (DFHXQ, DFHCF or DFHNC). These messages fall into the following groups:
These messages provide information about important status changes, primarily about the beginning and end of server initialization and the beginning and end of server termination, and about problems.
Any server message that is issued in this way during normal running indicates a potentially serious problem, and should not be ignored. If this process is automated, a simple rule is to ignore the specific list of status messages for normal initialization and termination, and to treat any other server message as a warning.
These messages can be issued either from the server address space or from a client address space. If the server code that requests the message is running in cross-memory mode, the message is passed back to a routine that issues the WTO in primary mode in the client address space. This avoids restrictions which apply to WTO messages that are issued in cross-memory mode. For example, cross-memory mode WTO messages do not appear in any job log.
These messages contain responses to server commands that are issued via the system MODIFY or STOP command, for example to display statistics.
These messages typically contain diagnostic information, for example details of an abend or an attempted security violation. They are written to the job log, by WTO with routing code 11 (programmer information).
These messages are written only to the server SYSPRINT file.
All messages that are issued by the server code, whether they are running under the server address space or in cross-memory mode from the client address space, are also copied to the server SYSPRINT file.
The AXM environment code issues operator messages from the server and client address spaces and from the master address space during AXM system services initialization. These messages are issued using WTO with routing codes 2 (operator information) and 11 (programmer information, not used when running in the master address space), and descriptor code 4 (system status). AXM message numbers are of the form "AXMxxnnnns", where the first five characters "AXMxx" are the name of the module issuing the message, "nnnn" is the numeric part of the message number, and "s" is the suffix letter. The suffix letter is "I" if the message is a routine informational message, or is omitted if the message indicates an error. The suffix letter can be used by automation tools to distinguish routine informational messages from error situations.
AXM messages that are issued from the server environment (via AXM run-time environment routines linked with the server load module), are copied to the server SYSPRINT file as well. AXM also writes informational messages to the SYSPRINT file. These contain information such as initialization information and closedown statistics for storage management, and the main procedure entry point of the server module for diagnostic purposes.