This documentation supports the 22.1 version of Action Request System.
To view an earlier version, select the version from the Product version menu.

Configuring how the mid tier manages cache

The first time a form, view, or form and view combination is requested via Mid Tier , performance can be impacted by the intensive processing necessary to obtain the form, field, active link, and associated information from AR System server . This can be time consuming when there are large forms with many fields and many associated active links. It is also important that memory is not consumed for forms that are not accessed.

Tip

While you upgrade Mid Tier , if the cache version number changes, the catalina.out file logs the following message, and Mid Tier rebuilds the cache:

CACHE: SetupServlet:init: Version change is detected due.
Older version = 0 New version = 5 Cache has to be flushed and rebuild

To minimize the usability impact of this performance hit, the Mid Tier Configuration Tool includes the following configuration options:

  • Flush cache—Removes all items from the Mid Tier  cache. When the objects are requested, the most up-to-date versions are retrieved from the AR System server . For details about the Flush Cache feature, see Configuring cache settings for the mid tier.
  • Sync cache—Clears only objects that have changed on the server after the last cache clear event. In this case the mid-tier contacts AR System server  and compares the last-changed-timestamp on elements and synchronizes any changes. For details about this feature, see Configuring cache settings for the mid tier.

    The Sync cache option is not available for 7.1.0 and prior releases.

    When you restart Mid Tier  (or Tomcat), it starts building views and performing sync cache operations to ensure that the cache contents are up-to-date. Loading those views in the cache takes time if there are a lot of AR System server  views in the viewstats.dat statistics file, which subsequently delays the sync cache operation. During this period, if mid tier gets any request, it sends the older version of the requested data. 

    As an administrator, you can check the sync status on the Cache Settings page to verify whether the sync was completed successfully.

  • Definition Change Check Interval—This Mid Tier  cache setting is configured to set an interval (in seconds) at which information in the cache is updated. The default value is 86400 seconds. For details about the Definition Change Check Interval setting, see Configuring AR System servers that the mid tier uses.

The following actions will affect an object cache or re-cache in the event of a flush cache, sync cache, or Definition change:

  • Add a user
  • Modify a user
  • Delete a user
  • Add a group
  • Remove a group
  • Remove a group from the Group List in the User form
  • Add a user to a group
  • Remove a user from a group
  • Add a computed group
  • Add a group to a computed group
  • Remove a group from a computed group
  • Add a user to a group that is part of a computed group
  • Remove a user from a group that is part of a computed group
  • Create, modify, or delete an application
  • Create, modify, or delete an active link
  • Create, modify, or delete an active link guide
  • Create, modify, or delete an entry in the Group form (not every field must be affected)
  • Create, modify, or delete an entry in the Role Mapping form (not necessarily every field)
  • Create, modify, or delete a form
  • Create, modify, or delete a menu
  • Create, modify, or delete a packing list
  • Create, modify, or delete a view
  • Create, modify, or delete a web service


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