Not being a php person I found this brief article to be the best explanation of sessions in php:
https://ma.ttias.be/php-session-locking-prevent-sessions-blocking-in-requests/
and I see work is being done on: https://tracker.moodle.org/browse/MDL-58018 (very interested!)
but my questions would be (and please correct any misunderstanding):
- can anyone provide a good overview of how session locking works in Moodle?
- does moodle take a lock on every REQUEST (GET and POST)?
- If so, why? Is this historical?
- shouldn't a lock only be taken explicitly by code that knows it is modifying data (i.e. DB/file writes) not generally?
Appreciate any light that can be shed on this, especially as lock contention is an issue for us.
Thanks,
john