Two possibilities :
1. If a job ("invoice processing batch") takes a long time, the
application could be spawning more connections to the database, thus
resulting in more sessions (processes) on the database. Have you compared
the time it takes to run the batches between the two environments ?
2. The trigger to create a new connection to the database may be lower in
the pre-production environment, resulting in more connections ?
Idle connection shutdown time from the application may be different on
pre-production (although you seem to have confirmed that it is the same in
both environments). How long do those INACTIVE sessions actually persist
in the non-prod environment ?
Hemant K Chitale
On Fri, Nov 16, 2018 at 10:55 AM Hameed, Amir <Amir.Hameed@xxxxxxxxx> wrote:
Hi,
I was recently engaged to troubleshoot an issue in a pre-production
environment which involves Oracle 11.2.0.4 database running on Solaris
server and IIS running on a Windows VM. On the IIS side, the minimum and
maximum connection pool settings are set to 100 and 4000 respectively. On
the Oracle database side, the processes and sessions parameters are set to
4000 and 6000 respectively. I have no visibility to IIS and I do not have
any experience with IIS either. I am relying on my understanding of how
connection pooling work in WebLogic Server to triage the problem. The
application processes thousands of invoices in multiple batches and each
batch can run up to 4000 invoices concurrently. The non-production
environment has similar setup (at least this is what I have been told).
When the application team runs load in non-production, it completes
successfully and we do not see more than 150 connections coming from the VM
(V$SESSION.MACHINE) and the INACTIVE session count goes down to 100.
However, the same load when run in the pre-production environment, it
consumes up to 4000 connections and this is a repeatable process. I have
been told that IIS is setup the same way in non-production and
pre-production environments. The default value of releasing idle
connections frequency in IIS is 30 seconds. However, after processing
invoices, even though connections established from the IIS VM have INACTIVE
status, connections are not getting released in the pre-production
environment and I am trying to understand the mechanism around how Oracle
database releases connections.
I believe (and I could be wrong) that Oracle does not automatically close
INACTIVE connections on its own and this is not the same situation as DCD.
Is it possible that even though IIS is trying to shrink the connection pool
but Oracle database is not releasing connections? Both non-production and
pre-production have same initialization parameters with the only difference
being the SGA size.
Any insight will be appreciated.
Thanks,
Amir
