Issue with Olap4j asynchronous calls
24 February, 2015
Hi,
I am getting errors on my YF dashboard with regards to querying an OLAP cube asynchronously.
This is my setup.
- I have 5 portlets, each showing a different report.
- Each portlet is set up to refresh on a 15 second interval.
- Each of the 5 reports uses the same YF Data Source, which is an XMLA connection to an MSAS cube. This uses olap4j (latest driver version).
When I just leave the dashboard open, I get random errors on the portlets. The YF log file shows a 'recursive population error'.
Searching this on Google, I find that the olap4j driver has issues with asynchronous calls.
See discussion here: http://sourceforge.net/p/olap4j/mailman/message/29155832/
When I set YF to load dashboard widgets synchronously, the errors go away. This is however a dev environment and I am currently the only user.
My question is: What happens when 10 - 20 users are viewing this dashboard. Will YF ensure that the olap4j driver is called synchronously? If not, is there any way I can ensure that this happens, e.g. a setting on Tomcat?
Thanks,
Dylan Erens
I am getting errors on my YF dashboard with regards to querying an OLAP cube asynchronously.
This is my setup.
- I have 5 portlets, each showing a different report.
- Each portlet is set up to refresh on a 15 second interval.
- Each of the 5 reports uses the same YF Data Source, which is an XMLA connection to an MSAS cube. This uses olap4j (latest driver version).
When I just leave the dashboard open, I get random errors on the portlets. The YF log file shows a 'recursive population error'.
Searching this on Google, I find that the olap4j driver has issues with asynchronous calls.
See discussion here: http://sourceforge.net/p/olap4j/mailman/message/29155832/
When I set YF to load dashboard widgets synchronously, the errors go away. This is however a dev environment and I am currently the only user.
My question is: What happens when 10 - 20 users are viewing this dashboard. Will YF ensure that the olap4j driver is called synchronously? If not, is there any way I can ensure that this happens, e.g. a setting on Tomcat?
Thanks,
Dylan Erens
Hi Dylan,
that's a very good question! and I'm please to be able to tell you that there is indeed some configuring you can do on the MSAS server that will ensure the issue with asynchronous calls will be resolved.
This issue can be fixed by configuring the IIS Application Pool that is being used, increasing the "Queue Length" and "Maximum Worker Processes" options, as described in this post.
After increasing the Queue Length setting from 1000 to 10000, and the Maximum Worker Processes from 1 to 10, then restarted IIS, then the asynchronous calls were no longer an issue.
We have tested this out ourselves, and also another customer last year (using SQL Server 2008), and we all found it to be an effective way of dealing with this issue.
Please let us know how you get on with this.
regards,
Dave
that's a very good question! and I'm please to be able to tell you that there is indeed some configuring you can do on the MSAS server that will ensure the issue with asynchronous calls will be resolved.
This issue can be fixed by configuring the IIS Application Pool that is being used, increasing the "Queue Length" and "Maximum Worker Processes" options, as described in this post.
After increasing the Queue Length setting from 1000 to 10000, and the Maximum Worker Processes from 1 to 10, then restarted IIS, then the asynchronous calls were no longer an issue.
We have tested this out ourselves, and also another customer last year (using SQL Server 2008), and we all found it to be an effective way of dealing with this issue.
Please let us know how you get on with this.
regards,
Dave