OLAP Cache Problem

[Former Member]

Hello,

I am having a strange problem with OLAP Cache. I have a web template with 4 queries, I cache the query results from Reporting Agent in the morning. For these queries the cache mode is set to Persistence mode as Flat file. The queries cache about 2MB data. When I run the web template the data read from cache and results displayed quickly. It works same way with everybody in the development group. When user runs the web template the data read from database and takes long time to display the result. My questions is Why the data is not read from cache/write in to cache when user run the report?

Does any body experienced this. Any help is greatly appreciated and rewarded.

Thanks,

Srinivas

[Former Member]

The problem is solved. It was an authorization issue for Flat files (I was using persistence mode of 'Flat file' across all servers). The basis team needed to add the physical path of BW_OLAP_CACHE to the authorization object S_DATASET.

Thank you all for your responses.

-Srinivas

[Former Member]

Hi Deepu,

The cache mode is "Persistent Cache Across Servers" with persistence mode as "Flat File". Out of Flat File, Cluster Table and BLOB Table which one is efficient to cache/read of size 2MB.

Thanks,

Srinivas

[Former Member]

So based on your response, you must have multiple Appl Servers and the setting to be Across Appl Servers you should be OK. Personally, if the query is used heavily, main memory is the fastest.

Among Flat File, Cluster, and BLOB, for 2MB, I would go with BLOB. BLOB generally should be faster for larger query results than Cluster. Cluster would be the choice for smaller.

There are a number of things that might be causing your problem -

Do you know if the users are changing any aspect of the query when they run vs the way it was run thru Reporting Agent?

Do they use a variable that your developers and Reporting Agent are not inputting?

Do they drill on a characteristic not drilled on in Reporting Agent?

What are the other query property settings?

Also, are your variables set so they can be changed during Navigation?

If you search the BI forums on OLAP Cache you'll fin other threads on the topic.

[Former Member]

The reporting agent and user execute with the same set of variable values, which are defaulted. When users execute the query it does not read from cache and also after displaying the result I don't see any entry cached by the user in RSRCACHE.

Is it something to do with authorization?

Because it works for all our developers.

Thanks!

[Former Member]

We're at the the same version - 3.1 SP21 with 2 Appl srvrs and have never seen this issue. It is strange that you are not seeing cache entries created. I'm not aware of any settings/options that would be at a user level.

I've never seen a situation where authorizations came into play for OLAP cache, but one never really knows with BW. I wonder if there could be a Server permissions issue with the flat file cache.

I think I would try moving the cache for this query to the BLOB (on local server and across servers) and main memory to at least see if the behaviour is the same across different cache options.

There are a couple RSADMIN entries with SP22 for OLAP cache that address some problems with the cache getting deleted, but those symptoms don't seem to be what you describe (user level issue), but it might be worth a quick look at Notes 856221 and 848055 just to be sure.

If I think of anything else, I'll reply again. Post again after changing the cache settings or if you learn anything. Curious......

Pizzaman

Did you confirm that users and developers are logging into the same Appl Servers, or or are they different?

[Former Member]

Do you have the cache mode Flat file for Application server or Flat File cache across Application server?

The issue could be the developers are logging on to the app server where the cache is stored and users are under a different log on group logging onto a different appp server.

Thanks.

[Former Member]

Sorry I for got to mention the system version. It is BW 3.1 at support package 21.