122 Geac System21 commerce.connect: Implementation on the iSeries Server
If WebSphere is the only significant application on your system, then the performance
adjuster may do a reasonable job. In this case, there may not be any value to a dedicated
memory pool for WebSphere.
If WebSphere will run alongside more traditional interactive and batch applications, such as
System21, then the performance adjuster does not seem to do a good job. It appears to favor
interactive jobs and reduces the memory of the WebSphere subsystem so much that
WebSphere performs very poorly. This even happens when interactive performance is
satisfactory and does not seem to require more memory.
In an extreme case, if WebSphere is idle for an extended period, its memory may be reduced
so much that it struggles to restart when someone starts to use one of the WebSphere
applications.
Therefore, if you have a mixed WebSphere and traditional workload, you may need to turn the
performance adjuster off and use manual tuning. To turn the performance adjuster off, sign on
as QSECOFR and enter this command:
WRKSYSVAL SYSVAL(QPFRADJ)
Type 2 next to the QPFRADJ system value, press Enter, type 0 on the next display, and press
Enter again. Of course, you may have to watch your system performance, and if necessary,
make further manual adjustments.
5.2.5 Manual performance adjustment
Most aspects of manual performance tuning for WebSphere are the same as for any other
application. The most useful tool for basic tuning is the WRKSYSSTS command. Watch the
faulting level, the wait to ineligible, and active to ineligible rates in the new WebSphere pool.
5.3 Stateless and stateful connections, datasources,
connection pools, etc.
The call.connect application uses both stateless and stateful JDBC connections.
5.3.1 Stateful connections
call.connect uses the Advanced Pricing module of System21. This module is stateful. This
means that it retains data that is relevant to the client between calls. If you price an order with
multiple lines, the price of a line may be affected by preceding lines. Quantity discounts may
apply to a group of items. Therefore, several lines ordering different items from the same
group may qualify for a discount, even though one line could not qualify by itself.
Stateful connections are not commonly used in WebSphere. call.connect uses special
support. The beans are still stateless session beans, but stateful connections are obtained
using a connection manager within call.connect. These stateful connections are managed
using a client ID so that a client obtains the same connection on each call.
This means that every active call.connect client requires a connection. This connection is not
managed by WebSphere and you do not need to consider it when sizing WebSphere
connection pools. However, you need to consider it when you configure iSeries SQL server
jobs.
vendor.connect does not use stateful connections.
