sybperl-l Archive

From: "Arne Claassen" <arne at mp3 dot com>
Subject: openclient overhead and connection concentrators
Date: Apr 27 2001 5:23AM

We've just brought up a farm of linux machines using DBD::Sybase that used
to connect to DBD::mysql, and the machines are suffering from some serious
load increases. From our investigation, the load is coming from the
increased overhead of opening and closing Sybase connections vs. mysql
connections. We confirmed this by connecting to a DBD::Proxy server on
Solaris, so that our farm just made DBD::Proxy connections and the Solaris
box did all the openclient connects/disconnect (btw, never got DBD::Proxy to
hold on to handles for caching). This slowed down the transactions, but the
load on the linux farm dropped significantly.

Our assessment is that we need some type of connection concentrator to cache
connections and avoid the constant opening and closing. The options we know
of are these:
- Apache::DBI - this will keep one open connection per apache thread, which
may turn into excessive open connections if we roll Sybase to more DBs
- DBD::Proxy - figure out why caching isn't working
- Roll our own Connection caching daemon to sit on each machine to reduce
the connection pool and keep connections open longer

Are there any connection caching/concentration daemons out there that people
are using, or how have you solved your overhead problems with web apps?

thanks,
arne