Chapter 5. Performance tuning 135
Figure 5-26 The Advanced page of the DataSource panel
Connection time out
This is the maximum time that WebSphere waits for a connection when all the connections in
the pool are in use.
If you frequently encounter connection time outs, then consider increasing the size of the
connection pool. See 5.3.2, “Stateless connections” on page 123, and 5.3.3, “Total
connections and SQL server jobs” on page 124, for more information.
If the problem occurs only occasionally during extremely busy periods and you do not want to
use additional SQL server jobs, then increase this limit. In general, the problem is better
addressed by increasing the pool size.
Idle time out
If the current size of the connection pool is above the minimum size, then connections are
released after they are idle for this time. They then return to the OS/400 pool. See 5.2.1, “SQL
server job configuration” on page 109, and 5.3.3, “Total connections and SQL server jobs” on
page 124, for more information. Depending on the SQL server job configuration, they may
then be as idle prestart jobs or released later in a similar way.
If there are times when WebSphere and non-WebSphere applications are busy, then setting
the minimum pool size less than peak usage may improve the performance of other
applications when WebSphere is below its peak. However, if WebSphere usage is fairly
constant or when it is idle and so are other applications, performance may be better with a
larger minimum pool size. Then this parameter will not be so important.
Orphan time out
This is the maximum amount of time that a transaction can hold a transaction. If it is
exceeded, then the connection is returned to the pool anyway. This is designed to prevent
failed or hung transacting monopolizing connections. However, if performance is poor, then a
valid transaction may have its connection removed and when it tries to use it the next time. It
