High load with "cleaning up" status

[Mike Zimmerman]

Recently our DB, which is running MySQL 3.23.52, started experiencing 
intermittant load spikes, of the magnitude of 200+ load averages. Normally, 
our high spike is about 0.90 load. When this starts happening, we notice a 
lot of processes "cleaning up" within the database. Can someone clue me in 
as to what cleaning up means, and what the possible cause of this is?


Thanks,

Mike Zimmerman