onstat -m Message Log

The onstat -m command displays the last 20 lines from the Informix Dynamix Server log which is specified by the MSGPATH parameter in the configuration file.

Notes

  • Checkpoint entries only appear in the log if pages were actually flushed to disk.
  • To handle server level errors, use the ALARMPROGRAM parameter in the configuration file.
  • With the latter engines onstat -m will work with the engine offline

Monitoring and Tuning

  • The message log should be monitored periodically for potential system problems. Should a session abort with an assertion failure, the message log will contain important information including a stack trace of the session.
  • For checkpoints, the online log identifies the interval (time between checkpoints) and the duration (the length of the checkpoint). The interval should be no less than the value of CKPTINTVL unless you are using the size of your physical log to control checkpoints (checkpoints occur when the physical log is 75% full). The duration of the checkpoint will vary depending on many factors (e.g., BUFFERS, LRU_MIN_DIRTY, LRU_MAX_DIRTY, CKPTINTVL, CLEANERS).
  • Other factors can cause checkpoints besides CKPTINTVL. Booting or shutting down the system, creating a DBSpace, or performing an archive are a few.
  • The message log should be cleaned out from time to time as it can become rather large on a highly active system. This task can be automated via the OS, for example under Solaris the command newsyslog