My forums have been performing new posts slowly for a while, now, but they were on old servers and old Windows OS. I just upgraded them all to a new, fast server and Windows 2012. They were still slow on posting which doesn't make sense because I have plenty of RAM free and CPU free while they're hanging.
Watching MySQL, the operation they would stick in is "freeing items" in "update ubbt_topics".
I updated two values:
innodb_thread_concurrency=32
innodb_flush_log_at_trx_commit = 2
It seems to be much, much better now.
Just in case anybody else hits this issue. Apparently I should have done this months ago (both the settings change and the server move).
I had always assumed before it was just the old system and old OS causing it.
