What is excessive swapping.
- by amateur barista
This post led me to ask that question.
Cache contention
On a large site, if you are using
MyISAM, contention occurs in the
database tables when the cache is
forced to clear after a node or a
comment is added. With tens of
thousands of filter text snippets
needing to be deleted, the table will
be locked for a long period, and any
accesses to it will be queued pending
the purge of the data in it. The same
is true for the page cache as well.
This often causes a "site hang" for a
minute or two. During that time new
requests keep piling up, and if you do
not have the MaxClients parameter in
Apache setup correctly, the system can
go into thrashing because of excessive
swapping.