FreeTDS Development Group

["Magnus Ahl" <Magnus.Ahl AT infogate.se>]

Nicholas Castellano wrote:

> I'd like to promote the pool server to a first-class member of the FreeTDS
> source tree.  Currently, we distribute it, and generate a Makefile for it,
> but it we don't build it or install it by default.  Is there any
> reason for me not to correct that situation?

Perhaps this should be considered once or twice. I've recently tested the
tdspool program for performance reasons, and found a few quirks with it:

1. The program is full of "fprintf(stderr, ... )" and there is no way to
turn of this _extremely_ verbose stderr logging, like a #define or something
similar.

2. The program behaves very strange on one of our servers (RedHat 8.0) in
the way that it keeps all connections alive until the program is forcefully
killed. Reverting from gcc 3.2 to gcc 2.95.3 and rebuilding the program and
the library does not fix this problem.

3. The program segfaults spontaneously after some moderate load for 120
seconds (apachebench with 1000 connections, 10 in parallel) and allocates
more than the number of concurrent threads used in the load test (10 threads
allocates 30 slots in tdspool).

4. Does the program really work? I actually get less or the same number of
accesses per second on our test webserver with pooling (apachebenc says 5.4
req/sec with pooling vs. 7.4 req/sec without pooling). Also _both_ the
database _and_ the webserver is _less_ loaded during the performance test
with pooling enabled, and all programs (CGI-programs, pool-program and
database) seem to be extremely idle as the load average never even reaches
above 0.6. Similar tests with MySQL as a local database peaks the server at
a load average of 10 and delivers 25 CGI-requests per second (Yes! that's
five times faster, with a local database!).


regards,

 Infogate AB             Magnus.Ahl AT infogate.se
 Storgatan 29                   tel: 035-171970
 Box 345                      mobil: 702-118265
 301 08 Halmstad                www.infogate.se