When attempting to browse the available "options" on my product class, and delete an option, I noticed extremely poor MySQL performance, with the mysqld process occupying 400% of the CPU for hours.

I immediately did a show processlist; and noticed several queries stuck in "statistics" state, with a few others stuck in "locked" state. The full processlist (and queries) are available here: http://pastebin.com/f5dba2db0 .

I tried to kill those queries and run an explain on the first one. This however, also locked MySQL up with the "statistics" state. Upon further investigation, I think this might be related to the following bug at MySQL: http://bugs.mysql.com/bug.php?id=26339

This bug describes the issue exactly, "Sometimes Querys with multiple inner join parts hangs during/after the execution."

Comments

chawl’s picture

chawl commented

Not particular to Ubercart, this happens without Ubercart also.

But subscribing anyway.

chawl’s picture

chawl commented

Hey, for MySQL, try adding this line to my.cnf:

optimizer_search_depth = 5

5 is an arbitrary low value. "0" means autodetect and seems to cause trouble for excessive number of joins, but you can try anyway.

Any progress?

longwave’s picture

longwave
he/him
Primary language English
Location UK
commented
Status: Active » Closed (duplicate)

Duplicate of #375019: Adjustments page breaks MySQL on too many attribute option combinations