Configure new datasource,certain terms

Question

Hi all,
while configuring a new data source, i am confused by certain terms, would appreciate if anyone can shed some light.
Under the connection pool settings:
Maximum Capacity: 20
According to BEA online help, its the "The maximum number of physical connections that this connection pool can contain". What if 25 users are accessing the application to access the database?
Capacity Increment: 2
According to BEA online help , its the "The number of connections created when new connections are added to the connection pool. When there are no more available physical connections to satisfy connection requests, WebLogic Server creates this number of additional physical connections and adds them to the connection pool." Does it mean if my maximum is 20, and there are 25 people using the database, weblogic will create 2+2+2 to connections to meet 25 connections?
Shrink Frequency:900 seconds
When shrinking occurs, WL will shrink it to what number? 20( which is my maximum capacity?

Answer 1

What version of weblogic are you using?
If WLS has 25 execute threads, then no matter
how many users are talking to WLS, it will only
really be processing 25 of these users at a
given instant, and with typical JDBC applications,
the connection from a pool is obtained, used and
returned, all within the thread's processing of
the current request, so no mattr how many users
are talking to WLS, it really only needs 25 connections
in the pool. Add 1 extra for safety.
Never alter Capacity Increment. It is of no help,
and might cause problems.
Shrinking will remove currently unused connections,
down to the initial capacity of the pool, or to the
recently observed average needed capacity,
whichever is larger. Unless you have a pressing
need to close DBMS connections, I recommend
against shrinking. It wastes time when load comes
back, to remake connecitons it could have kept.
Joe Wienstein