Chapter 5. Performance tuning 111
Figure 5-3 Display Prestart Job Entries list
Figure 5-4 shows the Display Prestart Job Entry Detail for the program QSQSRVR,
highlighting the number of jobs. Note the following parameters for this example display:
Start jobs parameter: The default is *NO. This means that the jobs do not start with the
subsystem. They only start when the first connection request is received. This causes
WebSphere to start slowly. This setting may be suitable if you rarely use WebSphere or
any other application that uses the native JDBC driver. Otherwise, we do not recommend
this setting.
Initial number of jobs parameter: The default is 3. If the previous parameter is set to *NO,
then this is the number of jobs that start when the first request is received. If the previous
parameter is set to *YES, then this is the number of jobs that start when the subsystem is
started. The default 3 is insufficient since even the WebSphere administration job
QEJBADMIN uses five native JDBC connections.
Threshold parameter: When the available jobs (those waiting) drop to this level, more
jobs will be started.
Additional number of jobs parameter: This is the number of additional jobs that are
started when the threshold is reached.
Maximum number of jobs parameter: IBM recommends that you set this parameter to
*NOMAX. You may notice that the pool identifier on your system is 1, rather than 2 as in
Figure 5-4. This is because the modification described in 5.2.3, “Subsystems and memory
pools” on page 115, was already applied to this system.
Figure 5-4 Display Prestart Job Entry Detail for QSQSRVR
