joegoarWe've been experiencing blog slow-downs & outages due to what appears to be both volume and mysql query issues.
One such query that keeps appearing in our db logs when having these issues is this extremely large update to the options table (where option_name = cron). BTW, we're still at wpmu 2.6.5 with plans to get to the latest version very soon.
The size of the value is ~685k. This seems ridiculous but from what I could gather this is where the (wordpress-version of) cron resides?
Is there any documentation out there on this? Specifically what triggers these updates, their purpose/need, etc. Is it related to posts being written, saved, published? Is the size of this update excessive or normal? We have about 20 editors in this env & have about 15 articles posted per day.
Here's a snippet of one such update:
Id User Host db Command Time State Info
5 xxx_user 192.x.x.x:62534 NULL Binlog Dump 724578 Has sent all binlog to slave; waiting for binlog to be updated NULL
439659 xxx_usr 192.x.x.x:52962 xx.dbname.xx Query 12 Locked UPDATE xx_1_options SET option_value = 'a:4908:{i:1251387290;a:1:{s:17:\\"wp_update_plugins\\";a:1:{s:32:\\"40cd750bba9870f18aada2478b24840a\\";a:3:{s:8:\\"schedule\\";s:10:\\"twicedaily\\";s:4:\\"args\\";a:0:{}s:8:\\"interval\\";i:43200;}}}i:1251387489;a:1:{s:9:\\"wp_rss_gc\\";a:1:{s:32:\\"40cd750bba9870f18aada2478b24840a\\";a:3:{s:8:\\"schedule\\";s:10:\\"twicedaily\\";s:4:\\"args\\";a:0:{}s:8:\\"interval\\";i:43200;}}}i:1251407618;a:1:{s:8:\\"do_pings\\";a:1:{s:32:\\"40cd750bba9870f18aada2478b24840a\\";a:2:{s:8:\\"schedule\\";b:0;s:4:\\"args\\";a:0:{}}}}i:1251407646;a:1:{s:8:\\"do_pings\\";a:1:{s:32:\
\"40cd750bba9870f18aada2478b24840a\\";a:2:{s:8:\\"schedule\\";b:0;s:4:\\"args\\";a:0:{}}}}i:1251407689;a:1:{s:8:\\"do_pings\\";a:1:{s:32:\
...
"40cd750bba9870f18aada2478b24840a\\";a:2:{s:8:\\"schedule\\";b:0;s:4:\\"args\\";a:0:{}}}}i:1257949119;a:1:{s:8:\\"do_pings\\";a:1:{s:32:\\
"40cd750bba9870f18aada2478b24840a\\";a:2:{s:8:\\"schedule\\";b:0;s:4:\\"args\\";a:0:{}}}}i:1257953079;a:1:{s:8:\\"do_pings\\";a:1:{s:32:\\
"40cd750bba9870f18aada2478b24840a\\";a:2:{s:8:\\"schedule\\";b:0;s:4:\\"args\\";a:0:{}}}}i:1257954025;a:1:{s:8:\\"do_pings\\";a:1:{s:32:\\
"40cd750bba9870f18aada2478b24840a\\";a:2:{s:8:\\"schedule\\";b:0;s:4:\\"args\\";a:0:{}}}}i:1257954044;a:1:{s:13:\\"sm_build_cron\\";a:1:{s:32:\\
"40cd750bba9870f18aada2478b24840a\\";a:2:{s:8:\\"schedule\\";b:0;s:4:\\"args\\";a:0:{}}}}i:1257955189;a:1:{s:8:\\"do_pings\\";a:1:{s:32:\\
"40cd750bba9870f18aada2478b24840a\\";a:2:{s:8:\\"schedule\\";b:0;s:4:\\"args\\";a:0:{}}}}s:7:\\"version\\";i:2;}' WHERE option_name = 'cron'
Any hints, tips, pointers are greatly appreciated.
