Stale or Orphaned Backends
A stale backend (also called an orphaned backend) is a backend for which AppDynamics has previously captured metrics, but which has experienced no metric activity for the configured time period.
You can configure AppDynamics to remove stale backends (database and remote service servers) automatically at a regular interval by setting the Controller-level global backend.permanent.deletion.period property.
If you are sharing a Controller on a SaaS account, contact AppDynamics Support.
When this Controller-wide property is enabled, AppDynamics removes all the stale backends in the managed environment, including any metrics previously collected for them and any health rules referencing their metrics. After a backend is removed, its metrics no longer appear in the Metric Browser and health rules that reference those metrics do not fire. You should remove any health rules conditions that reference metrics in stale backends.
By default, automatic removal of stale backends is enabled with a default interval of one month. The beginning of the interval is the last time that activity was reported on the backend (that Calls per Minute > 0) and the end of the interval is the time at which the backend is deleted.
You can modify the interval. This may be advisable, especially for large installations, since the maximum number of backends removed in one pass is 50. The minimum interval is one week.
You can also disable automatic removal by setting the interval to 0.
The automatic backend removal is logged in the server.log with the message:
BACKEND PURGER deleting unresolved stale backend ids:
followed by a list of the IDs being deleted.
To configure automatic stale backend deletion
1. Log into the Controller Administration Console using the admin account. See Access the Administration Console.
3. Scroll down to the backend.permanent.deletion.period property.
4. Enter the new interval in hours.
5. Click Save.