Defining the data set for JES2 initialization parameters

The HASPPARM DD statement defines a member in SYS1.SHASSAMP that initially contains the sample initialization data set. The sample initialization data set is only an example and requires system-specific modification. You will find it to be a useful base for coding your initialization data set(s).

When creating the JES2 initialization data set for your installation, you must move it from SYS1.SHASSAMP to a data set comprised of 80 character records in a fixed record format. The data set can be blocked with a BLKSIZE that is a multiple of 80. If your installation's SYS1.SHASPARM data set is not blocked, you can improve system performance by moving this member to a blocked library and tailoring the HASPPARM DD statement in the JES2 cataloged procedure accordingly.

Use the HASPPARM DD statement to define your initialization data set to replace the IBM-supplied null data set. You can also create the initialization data set separately and define it by its own DD statement in the procedure.

Your installations can use resources more efficiently by dividing the entire initialization data set into multiple members. Multiple members allow you to:

Separate JES2 parameters according to function.
Allow multiple programmers to manage distinct subsets of parameters.
Share a subset of parameters between the members of a JES2 MAS. (For the members of a JES2 MAS to share parameters, some HASPPARM data sets must be shared among all the members.)

To process multiple parameter members, you can either list them all in the JES2 procedure, using a concatenated DD for HASPPARM or use the JES2 INCLUDE initialization statement. To use the INCLUDE initialization statement, point the HASPPARM DD in the JES2 procedure to a single data set and member which contains the main JES2 initialization data set. This main data set can then INCLUDE each of the other initialization data sets. Use system symbolics to identify member–specific data sets that you need to include.

If JES2 cannot allocate a data sets specified on the HASPPARM DD statement, then you might need to start a backup JES2 procedure, or IPL a backup system to correct the problem. Using a concatenation of data sets for the HASPPARM DD increases the number of data sets that could cause a problem starting JES2. Using system symbolics in the JES2 procedure introduces another potential source of errors. Similar errors allocating data sets using the INCLUDE initialization statements will cause JES2 to enter console mode giving the operator an opportunity to correct the error without having to restart JES2. To ensure HASPPARM data set errors will not prevent JES2 from starting:

Point the HASPPARM DD to a single, specific data set and member that is not likely be changed.
Use INCLUDE statements in that initialization data set to add initialization statements from additional data sets.
Use system symbolics in the INCLUDE statement to identify member–specific data sets or members to include.

The initialization of JES2 supports the concatenation of data sets of unlike attributes as the initialization statement data set. This allows the use of a card reader to introduce the statements to JES2 by concatenating it to the standard PARMLIB initialization member while they are being tested by the installation.