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optimal Connection pool size?

babu lingam

Joined: Nov 21, 2002
Posts: 4
I am having WAS 3.5.3 running on Windows 2000, Oracle 8.1.7 database on a UNIX box. I am having 200 client application hitting the WAS box through a Servlet. Each application opens 4 connections directly from the oracle DB for some non WebSphere activity (as the client apps are written in VJ++, they use ADO to connection to the DB). Also, a few modules in the client apps post to the Servlet which needs 3 DB connections on an average.
So if one client app is running it requires 4 (thro ADO) + 3 (thro WebSphere Connection Pool) = 7 connections.
For 200 clients running concurrently 200 X 7 = 1400 connections are needed in the Oracle DB.
Is it reasonable to set
1)processes = 150 in init.ora in the oracle
2)Min Connection pool size = 10; Max Connection pool size = 600 in Datasource property of WAS.
The numbers ‘1400’ and ‘600’ looks huge.
Considering the performance how much will be optimal value for each of the settings?
I found this in WAS info center :
Rule Of Thumb to calculate Max connectin pool size:
n* (T * (C - 1) + 1)
T = no of threads
n = no. of client apps. Which initiates these threads
C = no. of DB connections opened by each thread
Applying this formula in my case 200*(1*(3-1) +1) = 600.
Any suggestions would be helpful
Thanks in advance
David O'Meara

Joined: Mar 06, 2001
Posts: 13459

You have also asked this question in the JIG (advanced) forum.
Please don't ask the same question in multiple forums, it creates duplicate conversations and wastes time.
The thread in JIG (advanced) has been moved to the IBM/WebSphere forum here and has received a reply, so I'm closing this thread.
I agree. Here's the link:
subject: optimal Connection pool size?
It's not a secret anymore!