Posted by ncrofts on Dec 12, 2010; 11:41am
URL: https://discuss.orbeon.com/Slow-page-load-tp2768407p3084214.html

Hello Erik,

Sorry to interrupt this thread, but the 30-40MB figure mentioned in the OP's message triggered a thought here. For what it is worth, we also see significant amounts of memory being consumed every request and the figure of 30-40MB per request is about what I see too when using a pretty basic XForms.

We have two main applications. One which does not use Xforms, but does make use of XPL pipelines to process and serve up XML data. The XPL-based application also uses more memory per request than I would like, around 5-10MB each request. The XPL typically perform a database transaction out to MySQL and then apply some XSLT transforms to the data before serializing the data via HTTP.

The second app we have is using Xforms, but not currently using Forms Builder, just hand-coded XForms. Again, these get their data by querying a db, transforming and then displaying in Xforms. The forms themselves. Every page request seems to cause about 30-40MB of memory to be consumed.

Both applications are running in Tomcat 6.x with Java 6.x and also connect to MySQL 5.x

The consequence of the above is that we are having significant problems scaling up the applications.

I appreciate these figures are very anecdotal, but the main point being that there is seems to be a huge memory overhead when it comes to serving up the XForms pages and to be honest the XPL based app is not great either. I may well be being rather naive about the memory management, but it does seem really excessive that such huge amounts of memory are being consumed to serve up really quite small and simple pages.

I'm hopefully going to be able to do some more profiling soon, as I really need to make this more scalable than it is at the moment. However any thoughts / experiences about what the most likely causes of the large memory use would be helpful and may help tackle this issue which I fear is a major disadvantage of the current platform.

Thanks in advance for any help.

Regards,
Neil