Input and output events data sets for end-to-end scheduling with fault tolerance capabilities (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 with operations running on fault-tolerant workstations and are used by both the End-to-end enabler task and the translator process in the scheduler’s server.

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 amount 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 quantity 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. Two cylinders are sufficient for most installations.

The maximum length of the events logged in these two data sets, including the joblogs, is 160 bytes. Anyway, it is possible to allocate the data sets with a longer logical record length. Using record lengths greater than 160 bytes does not produce either advantages or problems. The maximum allowed value is 32000 bytes; greater values will cause the E2E 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 160 bytes. When the record length of 160 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 in order to be able to decide how to build the job name in the symphony file (for details about the TWSJOBNAME parameter in the JTOPTS statement, see Customization and Tuning).

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

Initially, you might need to test your system to estimate the number and type of events that are created at your installation. When 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 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 E2E event data sets are not migrated or moved.