Friends,
I have been thinking about my smp db server and how it interacts with my
web server. I'm using mod_perl on Apache, which uses Apache::DBI to connect
to the db server via a private network segment. It occurs to me that since
the web server is connecting early (on startup), when there is probably no
load on the db server, the cpu that each backend is assigned to will be
largely random, or, if there is a large syslogd operation or something right
at that time, it might even put the majority of backends on the same
processor.
When someone hits the web site it seems to me that there would be a greater
than 50% chance that any two large queries from the web server would end up
being run on the same processor. Similarly, if I start a large processing
script that uses the db, since the web associated backends are already
assigned to a processor, there's a good (~50%?) chance that any big queries
that come in through the web will be on the loaded cpu.
Does this make sense to anyone? If this is true, are there any suggestions
about how I can keep my persistent connections from Apache, while getting
the db server to balance the load more efficiently?
Thanks,
Peter Darley
