D.0 Caching Computed Facts in a Grid with Large Numbers of Resources

If your Orchestration grid includes a large number of resources with associated Computed Facts, it is likely that these computed facts are evaluated with each Ready for Work message received by the broker from the Orchestration Agent. These evaluations can cause an excessive load on the Orchestration Server, causing a decrease in performance. You might see warnings in the server log similar to the following:

07.07 18:27:54: Broker,WARNING: ----- Long scheduler cycle time detected -----
07.07 18:27:54: Broker,WARNING: Total:3204ms, JDL thrds:8, TooLong:false
07.07 18:27:54: Broker,WARNING: Allocate:0ms [P1:0,P2:0,P3:0], Big:488
07.07 18:27:54: Broker,WARNING: Provision:4ms [P1:0,P2:0,P3:0], Big:253
07.07 18:27:54: Broker,WARNING: Msgs:3204ms [50 msg, max: 3056ms (3:RFW)]
07.07 18:27:54: Broker,WARNING: Workflow:[Timeout:0ms, Stop:0ms]
07.07 18:27:54: Broker,WARNING: Line:0ms, Preemption:0ms, (Big: 3), Mem:0ms
07.07 18:27:54: Broker,WARNING: Jobs:15/0/16, Contracts:10, AvailNodes:628
07.07 18:27:54: Broker,WARNING: PermGen: Usage [214Mb] Max [2048Mb] Peak
[543Mb]
07.07 18:27:54: Broker,WARNING: Memory: free [1555Mb]  max [3640Mb]
07.07 18:27:54: Broker,WARNING: Msgs:483/50000 (recv:128692,sent:14202),
More:true
07.07 18:27:54: Broker,WARNING: ----------------------------------------------

To work around this issue, we recommend that you cache the Computed Facts.

  1. In the Explorer tree of the Orchestration Console, expand the Computed Facts object, then select vmbuilderPXEBoot.

    The vmbuilderPXEBoot fact does not change, so setting the cache here is safe from any automatic modifications.

  2. In the Computed Facts admin view, select the Attributes tab to open the Attributes page.

  3. In the Attributes page, select the Cache Result for check box, then in the newly active field, enter 10 minutes (remember to change the drop-down list to indicate Minutes).

    This value must be greater than the default of 30 seconds.

  4. Click the Save icon to save the new configuration.

NOTE:If necessary, you can also cache other computed facts to improve server performance.