Approximately 1 month ago my drupal installation started intermediately slowing down (long page loads) and at times would give the drupal error message “unable to connect to database”.
My server management company told me this error was occurring because the mysql limit was being reached because certain queries were hanging and taking a long time to execute (I have a small sample log to take a look at for an example).
In addition, I also started receiving mysql/php errors on the hompage (example, “Warning: Cannot modify header information – headers already sent”, I have a txt file with this as well).
I also started receiving mysql/php errors in the drupal admin log. There were deadlock errors as well as “SELECT command denier to user” and “Dupliate entry” errors on various tables. The ‘select command denied & ‘dupliate entry’ always occur on my gsitemap so I’m concerned my sitemap is not being updated properly and/or is messed up. I should mention I’ve also witnessed these errors on a few other tables.(I have a txt file with these examples as well).
Members have also experienced issues with logging in and staying logged in, I believe it’s related to the cache.
I should mention that before this occurance the site has been running great since switching servers last September, and that this issue seemingly came out of the blue.