SIT
System initialization table: the set of start-up parameters that tells a CICS region how to run.
Also written system initialization table, SIT parameters, SIT overrides, DFHSIT
The SIT, or system initialization table, holds the settings a CICS region reads when it starts. It is to CICS roughly what PARMLIB is to z/OS.
There are many parameters. Some common ones: APPLID gives the region its name on the network. GRPLIST names the list of CSD groups to install. START sets the start type. MXT sets the maximum number of tasks. SEC=YES switches on security checking. Storage limits set how much memory the region may use.
Sites usually build a base SIT and then change individual values for each region with SIT overrides, typed as parameter lines in the region's start-up JCL. That way twenty regions can share one base, each with its own name and a few different settings.
Changes to SIT values usually take effect only at the next start of the region, so they are planned and tested like other system changes. When a region behaves differently from another one that should be the same, comparing their SIT overrides is a quick place to start.
Where can I learn this hands-on?
Right here, at ZedBank. You take a junior job at a simulated bank and learn each part of the work by doing it, with Zed beside you. There's nothing to install.
Start at ZedBankRelated
- CICS regionOne running copy of CICS, with its own programs, files and users. A site typically runs several.
- Cold startStarting a system such as a CICS region without restoring its previous state, as opposed to a warm or emergency start.
- CEDAThe CICS transaction used to define resources such as programs, transactions and files, and install them in a running CICS region.
- Started taskA long-running program that the system starts and leaves running, rather than a job that runs once and finishes.
- PARMLIBThe library of members that holds z/OS's own settings, read when the system starts and on some commands.