How the network print server is accessed

Before a client can communicate with the network print server, a communications session must be established. A communications session is a logical connection between two systems through which a client program on a local system can communicate with a server program on a remote system.

After a communications session has been established, the client can start the network print server by sending a special record, called a program start request (PSR), to the iSeries server. The communications session you use can utilize different protocols. Refer to the appropriate documentation for that communications type for information on using program start requests (PSRs).

After the network print server program has been started using a PSR, a communications transaction has been started. A communications transaction is a logical connection between two programs on a communications session. After this communications transaction starts, data can be exchanged between the client and the network print server.

Prestart jobs and the network print server

Prestart jobs provide increased performance between a program start request (PSR) initiated by a client and the network print server. Prestart jobs are defined within a subsystem. Prestart jobs become active when that subsystem is started or they can be controlled with the Start Prestart Job (STRPJ) and End Prestart Job (ENDPJ) commands.

The program name contained in the PSR from the client must be defined in the prestart job entry. This is how the PSR attaches itself to a prestart job and therefore achieves better performance.

The network print server has prestart jobs defined in the QBASE and QCMN subsystems. The number of prestart jobs that automatically start to support the network print server is small and thus saves system resources.

Monitoring prestart jobs for the network print server

Monitoring prestart jobs for the network print server in the QBASE or QCMN subsystem can be done using the Display Active Prestart Jobs (DSPACTPJ) command. For the network print server, you need to know the subsystem your prestart jobs are in (QBASE or QCMN) and the program for which the prestart jobs are started (QNPSERVR).

This command provides the following information:

• Prestart jobs:
  • Current number
  • Average number
  • Peak number
• Prestart jobs in use:
  • Current number
  • Average number
  • Peak number
• Program start requests:
  • Current number waiting
  • Average number waiting
  • Peak number waiting
  • Average wait time
  • Number accepted
  • Number rejected
    Note:
    The network print server never rejects a PSR. All PSRs are handled, or they are queued and use the next available prestart job.

Changing prestart job entries

The information presented for an active prestart job can be refreshed by pressing the F13 key while on the DSPACTPJ display. Of particular interest is the information about PSRs. This information can indicate to you whether or not you need to change the available number of prestart jobs. If you have information indicating PSRs are waiting for an available prestart job, you can change prestart jobs using the Change Prestart Job Entry (CHGPJE) command.

Following is an example of a prestart job entry in the QBASE subsystem for the network print server.

SBSD(QSYS/QBASE) +
PGM(QSYS/QNPSERVR) +
USER(QUSER) +
STRJOBS(*YES) +
INLJOBS(1) +
THRESHOLD(1) +
ADLJOBS(3) +
MAXJOBS(*NOMAX) +
JOB(*PGM) +
JOBD(*USRPRF) +
MAXUSE(200) +
WAIT(*YES) +
POOLID(1) +
CLS(QGPL/QCASERVR *CALC *NONE *CALC)

If the PSRs were not being acted on fast enough, you could:

• Increase the Initial number of jobs (INLJOBS) parameter value.
• Increase the Additional number of jobs (ADLJOBS) parameter value.

When the Threshold (THRESHOLD) parameter value is reached, the additional number of jobs are prestarted.

The key is to match the number of prestart jobs to the number of PSRs that are being sent. Keeping this association as close to one-to-one ratio ensures peak system performance.

Additional prestart jobs can be started if the number of program start requests to the network print server exceeds the number of available prestart jobs.