When the "Delete History List Messages" administrative task is run, the Strategy Intelligence Server logs in each user within the selected user group, and checks for history list messages that have passed the expiration date, deleting any that it finds. The scheduler may not, however log out the users after this action is completed, and typically the user sessions created by the scheduler are logged out in accordance with the Intelligence Server scheduler session time-out setting.
This processing is done asynchronously, meaning that the server does not wait for one user session to complete processing before starting the next. User sessions are created in rapid succession, with several sessions overlapping. This task consumes a great deal of server resources and should be scheduled for a time when the server is not busy with other user activity.
If processing of history list deletion is slow for any reason, or there are not enough user sessions available in the project to handle the required concurrency, some of the scheduled user session logins will fail. The Strategy Intelligence Server will not try again later to process these users' history list. In this situation, the task will appear to perform sporadically, sometimes running correctly and sometimes omitting some users from processing.
This symptom has been observed when this task was scheduled to execute simultaneously with several large, complex reports. Other circumstances could result in the same behavior.
Troubleshooting:
Users should log the counter - Strategy Performance Counter - Strategy Server Users - Open Sessions - to track the number of user sessions during the time that the schedule is expected to run. If this counter peaks at a value higher than the number of user sessions per project or at the Intelligence Server level, it is likely that some of the users in the group failed to be processed. As a result some history list messages may not be deleted.
Actions:
