Step 3. Running the generated sample to allocate the end-to-end data sets

About this task

Allocate the files and directories required to use the end-to-end scheduling with fault tolerance capabilities. The server starts multiple tasks and processes using the UNIX™ System Services (USS) on z/OS®. The end-to-end server accesses this in a z/OS® File System (ZFS) cluster. Sample JCL EQQPCS06 is generated by the EQQJOBS8 dialog.

Run EQQPCS06 to allocate the following files:

End-to-end script library (EQQSCLIB)

This script library data set includes members containing the commands or the job definitions for fault-tolerant workstations. This data set identifies the SCRPTLIB to whose members every job running on a fault-tolerant workstation must be associated (unless the job uses a centralized script). It is required in the controller if you want to use the end-to-end scheduling with fault tolerance capabilities.

Do not compress members in this Partition Data Set (PDS). For example, do not use the ISPF PACK ON command, because IBM Z Workload Scheduler does not use ISPF services to read it.

End-to-end data set for centralized script support (EQQTWSCS)

IBM Z Workload Scheduler uses the end-to-end centralized script data set to temporarily store a script when it is downloaded from the JOBLIB data set to the agent for its submission.

If you want to use centralized script support when scheduling end-to-end, you need to use the EQQTWSCS DD statement in the controller and server started tasks. The data set must be a partitioned extended data set.

End-to-end input and output events data sets (EQQTWSIN and EQQTWSOU)

These data sets are required by every IBM Z Workload Scheduler address space that uses the end-to-end scheduling with fault tolerance capabilities. They record the descriptions of events related to operations running on fault-tolerant workstations and are used by both the end-to-end enabler task and the translator process in the server of the scheduler.

The data sets are device-dependent and can have only primary space allocation. Do not allocate any secondary space. They are automatically formatted by IBM Z Workload Scheduler the first time they are used.

Note: An SD37 abend code is produced when IBM Z Workload Scheduler formats a newly allocated data set. Ignore this error.

EQQTWSIN and EQQTWSOU are wrap-around data sets. In each data set, the header record is used to track the number of read and write records. To avoid the loss of event records, a writer task does not write any new records until more space is available when all the existing records have been read.

The amount of space that you need to define for each data set requires some attention. Because the two data sets are also used for joblog retrieval, the limit for the joblog length is half the maximum number of records that can be stored in the input events data set. 10 cylinders are sufficient for most installations.

The maximum length of the events logged in these two data sets, including the joblogs, is 120 bytes. However, it is possible to allocate the data sets with a longer logical record length. Using record lengths greater than 120 bytes does not produce either advantages or problems. The maximum allowed value is 32000 bytes; greater values cause the end-to-end task to terminate. In both data sets there must be enough space for at least 1000 events (the maximum number of joblog events is 500). Use this as a reference if you plan to define a record length greater than 120 bytes. So, when a record length of 120 bytes is used, the space allocation must be at least 1 cylinder. The data sets must be unblocked and the block size must be the same as the logical record length. A minimum record length of 160 bytes is necessary for the EQQTWSOU data set to choose how to build the job name in the symphony file (for details, see the the TWSJOBNAME parameter of the JTOPTS statement).

To improve performance, define the data sets on a device with plenty of space availability. If you run programs that use the RESERVE macro, try to allocate the data sets on a device that is not, or only slightly, reserved.

Initially, you might need to test your system to get an idea of the number and type of events that are created at your installation. Once you have gathered enough information, you can then reallocate the data sets. Before you reallocate a data set, ensure that the current plan is entirely up-to-date. You must also stop the end-to-end sender and receiver task on the controller and the translator thread on the server that use this data set. EQQTWSIN and EQQTWSOU must not be allocated as multivolume.

Note: Do not move these data sets once they have been allocated. They contain device-dependent information and cannot be copied from one type of device to another, or moved around on the same volume. An end-to-end event data set that is moved will be re-initialized. This causes all events in the data set to be lost. If you have DFHSM or a similar product installed, you should specify that end-to-end event data sets are not migrated or moved.

Current plan backup copy data set to create the Symphony file (EQQSCPDS)

During the creation of the current plan, the SCP data set is used as a CP backup copy for the production of the Symphony file. This VSAM is used when the end-to-end with fault tolerance capabilities environment is active. It should be allocated with the same size as the CP1/CP2 and NCP VSAM data sets.