Short Term Canister

One component of a Discover Canister, the Short Term Canister is an in-memory database used for storing active sessions.

About this task

To review information on an STC, in the Canister Status report select the individual Canister that you wish to review from the Unica Discover drop-down. The following areas of the report can be reviewed to check STC health.

  • Determine if hits are even arriving in the Canister. See No hits arriving into Canister. If some hits are arriving, continue with these steps
  • Session Timeout. This value in seconds defines how long idle sessions are permitted to remain open in the Short Term Canister without updates or changes applied to them.
    • For more information on changing this setting, see "Configuring the Canister" in the Unica Discover Configuration Manual.
  • Sessions waiting for archive to disk. This value indicates the number of sessions that have been marked for closing but have not been written to disk in the Long Term Canister. See Sessions waiting for archive to disk.
    • A high number for this value typically indicates disk storage problems, I/O problems with the storage media, and processing resource issues.
      • Disk storage: Verify the amount of free disk space available under Disk Usage: Server Free Disk Size.
      • I/O problems: To verify I/O problems, use your external disk monitoring tools.
    • processing resource issues: It's possible to increase the number of session processors in the STC. However, adding these threads does cost available CPU and RAM resources. See Hit Processors.
  • Memory In Use. If this figure is greater than 80% in most deployments, hits submitted to the STC for evaluation are spooled to local disk for later processing. See Spooling.
  • Non Evaluated Hits. A non-zero figure indicates that the Short Term Canister is having difficulty processing events. See Event processing.

For more information on this report, see Single Server under System Status.