We have a very wierd problem. We generate hundreds of reports nightly for clients using an automated process which invokes SQL2008 SSRS web services to render the reports (which we then save to the file system). 80% of the time the reports generate without issue. Approximately once a week SSRS seems to "freeze" - it seems to be processing for hours when the reports should really take only minutes. Nothing unusual shows in the logs (originally we saw some "discard results" messages and upgraded to the SP2). The only thing that seems to work is to reboot the SSRS server and DB server and re-run the reports. Doesn't make a lot of sense. The reports also run overnight when there is virtually no other DB activity (so locking is not likely an issue). Can anyone suggest a way to diagnose this?

Hi Bob, How about your system resource then? like ram, cup and hard disk I/O performance in windows performance monitor. Besides this, when SSRS is freezed, please check whether there is some backend programs running. Like anti-virus programs, backup software. thanks, Jerry

It is very hard to diagnose. We don't see any DB locking. We see Report Server sql processes but they are all sleeping awaiting command. CPU and memory utilization is very low. If we attempt to run the report manually during this period, it also freezes. At this point we don't know where to look further to attempt to resolve this.

One more thing to add. We did some tracing this morning during a freeze and the stored procedures which return the report data are not being executed. We see Report Server meta data queries and stored procedures but not those we use within our reports. So it seems to freeze before executing the reports. Restarting the SQL Server service resolves the issue but this is obviously not a good solution.