RE: Connection pool with Apache::DBI and Oracle

[Georg Botorog]

I don't understand. The Apache server I am using has 50 ThreadsPerChild
(default in httpd.conf). Thus, Apache is able to handle quite a few
requests simultaneously. However, Oracle has only one session for the
job. As a consequence, starting two identical requests from distinct
clients leads to blocking the second request until the first one is
served. Now, to my modest understanding, this is bottleneck.

But maybe I'm doing something wrong here. Or perhaps I have
misunderstood something.



 -Original Message-
 From: Perrin Harkins [SMTP:[EMAIL PROTECTED]]
 Sent: Friday, January 24, 2003 7:30 PM
 To:   Georg Botorog
 Cc:   [EMAIL PROTECTED]
 Subject:  Re: Connection pool with Apache::DBI and Oracle
 
 Georg Botorog wrote:
  More precisely, I am using Apache::DBI to create and cache the
  connection to the DB. As this connection uses a single Oracle
 session,
  it is obvious that it becomes a bottleneck.
 
 Apache::DBI uses one connection per process.  There is no bottleneck 
 there.  Each process only handles one request at a time so it would
 have 
 no use for more than one database connection.
 
   Ideally, one would have a pool of DB
  sessions (= DB handles) that the Apache threads would use in serving
 the
  requests coming from clients.
 
 That's only ideal if your code spends a lot of time doing things that 
 don't involve a database.  You shgould be running with a reverse proxy
 
 in front, so that mod_perl processed will not be serving static files.
 
  Alternatively, is it possible to convince several Apache servers
 running
  concurrently to cooperate (i.e., load balance) in answering incoming
  requests? If yes, how?
 
 Any load-balancer will do that.  There are dozens, both commercial and
 
 open source.  See the mod_perl documentation for a list you can start
 with.
 
 - Perrin
 

Re: Connection pool with Apache::DBI and Oracle

[Perrin Harkins]

Georg Botorog wrote:

More precisely, I am using Apache::DBI to create and cache the
connection to the DB. As this connection uses a single Oracle session,
it is obvious that it becomes a bottleneck.


Apache::DBI uses one connection per process.  There is no bottleneck 
there.  Each process only handles one request at a time so it would have 
no use for more than one database connection.

 Ideally, one would have a pool of DB
sessions (= DB handles) that the Apache threads would use in serving the
requests coming from clients.


That's only ideal if your code spends a lot of time doing things that 
don't involve a database.  You shgould be running with a reverse proxy 
in front, so that mod_perl processed will not be serving static files.

Alternatively, is it possible to convince several Apache servers running
concurrently to cooperate (i.e., load balance) in answering incoming
requests? If yes, how?


Any load-balancer will do that.  There are dozens, both commercial and 
open source.  See the mod_perl documentation for a list you can start with.

- Perrin