SYMPTOM:
Reports that normally hit cache are executed against the warehouse instead of hitting the cache directly during periods of a high user load on the system. Users may also observe during these periods that new cache files are created on the Strategy Intelligence Server
In association with this behavior the following errors may be observed in the Report Server Cache Trace output:
2008-08-18 09:46:02.359 Failed to load cache. CacheID A5282F404EDDDA84AE5D43B5C0FF65CA, Error Code 554.
The error code 554 indicates that not enough memory was available for the cache file to be loaded.
CAUSE:
If caching works as expected during low load conditions, the likely cause of this issue is an insufficient amount of memory assigned to report caches. Under normal conditions, if a cache cannot be held in the available memory allocated for the project's caches, the cache is unloaded to disk. If a subsequent report execution requires this cache, the Intelligence Server will unload a cache currently in memory and load back the cache on disk. In the situation of high workload however, when many users try to load several different cached reports and the amount of memory allocated for caches is small compared to the concurrent report cache requests, the Strategy Intelligence Server may be unable to unload and load caches from disk. Users in this scenario will experience some reports executing against the warehouse instead of retrieving from cache.
ACTION:
To alleviate the problem, more memory for report caches needs to be assigned. This can be done by changing the value of Maximum RAM usage setting in Caching section of Project Configuration window. The appropriate value for this setting depends on the expected number of report caches that will be created for the project, the size of these caches, and the peak load conditions.
