As I have written here http://drupal.org/node/88452, I and as before withe Drupal 4.6, also now, with drupal 4.7.4 there comes a point when the server is returning the annoying 503 message (service unavailable) for couple of minutes.
What could be the cause?
I have successfully updated to 4.7.4, switching modules one by one.
I have following modules on:
- forum
- blog
- event
- privatemsg
- user_view
- book
- buddylist
- comment
- feedback
- flexinode
- image
- image attach
- image gallery
- image assist
- locale
- og
- og basic
- page
- path
- pool
- print
- profile
- sitemenu
- taxonomy
- tracker
- upload
- ulrfilter
could it be the number of modules?
My long search, trying, googling have brought me to the following POSSIBLE causes:
- I have cashing enabled, speeds up the site, however the problem is not solved
- I disabled unnecessary modules, just have a minimum, but problem persists
- I have tried 4.7.3 but problem persists
- problem seems to occur where more than one user try to acces one table, LOCK table issue?
- it is to do with localisation?
- I do OPTIMIZE database and
- I do empty Sessions, cache watchdog tables from time to time.
- could it be my provider setup problem? (his limits of performance on one site?)
- anything else I am not aware of?
I start to feel desperate with my drupal installation. Would a