We have a web application running multiple instances on different plesk servers. On one server we see quick generation of php session files under /var/lib/php/session directory. Which grows in 100 thousands in short period of time and clean-up of session files causes server load.
On other server we do not see such issue. What possible php (session) setting can cause creation hundreds of session files in seconds. it is looks like on each request to server cause creation of new session file. It does not look like php programatic issue because same application instance is running on other server not causing this issue.
Thank you for your suggestions.