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optimal Connection pool size?

 
babu lingam
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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)
where
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
babu
 
Michael Ernest
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Moving to WebSphere forum
 
Michael Zalewski
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If your init.ora says max 150 processes, you cannot have 200 clients opening 200 x 4 connections. Number of clients would only be the number of clients simultaneously connected to WAS, processing a request. If there are 200 active sessions, and if it takes the user 2 minutes to complete a page on the client, and if the response time is 5 seconds, you probably have like 100 connections max. (which is probably how your processes got increased to 150).
 
Kyle Brown
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Michael is right -- given 200 clients TOTAL I would guess the actual # of simultaneous threads is closer to 20.
Kyle
 
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