[djbaxter]

I was experiencing intermittent very slow posting and double posting after transfer to a new VPS.

We were able to identify some problem plugins in investigating this and it turns out this was one of them.

From the host tech support:

It looks like there's a specific query being ran that's really slowing down your server.

SELECT * FROM `filedata`;
# Time: 171007 13:22:30
# User@Host: ###### @ localhost []
# Thread_id: 318579  Schema: #####  QC_hit: No
# Query_time: 7.152743  Lock_time: 0.000120  Rows_sent: 31  Rows_examined: 558
# Rows_affected: 0
SET timestamp=1507396950;
SELECT  post.pagetext AS preview,
                        thread.threadid, thread.title AS threadtitle, thread.forumid, thread.pollid, thread.open, thread.postusername, thread.$
                        thread.dateline, thread.notes, thread.visible, thread.sticky, thread.votetotal, thread.attach, thread.lastpost, thread$
                        thread.prefixid, thread.taglist, thread.hiddencount, thread.deletedcount, user.userid,
                        user.membergroupids, user.infractiongroupids, user.usergroupid, user.homepage, user.options AS useroptions, IF(userlis$
                        user.lastactivity, user.lastvisit, IF(user.options & 512, 1, 0) AS invisible


                        , (SELECT COUNT(*) FROM starposts AS starposts WHERE starposts.userid = 0 AND starposts.threadid = thread.threadid) $
                FROM thread AS thread
                        LEFT JOIN user AS user ON (user.userid = thread.lastposterid)
                        LEFT JOIN userlist AS userlist ON (userlist.relationid = user.userid AND userlist.type = 'buddy' AND userlist.userid$


                        LEFT JOIN post AS post ON(post.postid = thread.firstpostid)

                WHERE thread.threadid IN (0,32490,26504,31904,31744,31657,31635,31567,27852,31374,31276,27962,31157,30175,29848,29692,29680,29$
                ORDER BY thread.sticky DESC, lastpost DESC;

The reason it's taking so long, is that it's using LEFT JOIN commands that will take information from a previous query, and use it into that specific query which can really slow your server down.