Hello,
I have inherited an PHP application that makes extensive use of XML and XSLT. After upgrading PHP from 5.4.xx to 5.5.23, the memory usage of transformations using XSLTProcessor::transformToDoc have gone through the roof.
I have debugged the PHP and XSL as much as I can even though nothing in the code itself changed - just upgraded PHP.
In an example transformation involving an XML file that is 2.9MB in size, the PHP/Apache process prior to the transformToDoc call shows 390MB of memory usage and immediately following the transformToDoc call, the process shows to be consuming 2.4GB of memory. (The PHP function memory_get_usage() returns 6461888, so PHP doesn't hit its memory_limit.)
I don't have any hard numbers from the PHP 5.4 setup, but there were no memory spikes like this. With larger XML documents, we are seeing a single Apache process consume 50+GB of memory.
Any help will be appreciated.