Memory classes of a UTM application

For the storage space required by the UTM product files and of a UTM application, refer to the release notice.

The table below lists the components that require address space in one of the memory classes 4, 5 or 6 while UTM applications are running:

Component	Class	Explanation
openUTM V6.2 system code	4	1.
Static KAA tables	5	2.
Dynamic KAA tables	5	3.
Cache	(5)	4.
KTA tables	5	5.
ROOT system modules	6
Additional requirement for formatting	6	6.
Additional requirement for DB system	6	7.
Administration program KDCADM	6
Program units of the user	6	8.

Explanation

1. openUTM system code:
   The UTM system code, including the operating system adaptation module, is loaded by BS2000 subsystem management DSSM in the class 4 memory. The UTM base components, including the operating system-adapter module and the UTM-D code including XAP-TP, belong to the UTM system code. Further details can be found in section"Installing openUTM".

2. Static KAA tables (KDC Application Area):
   KDCDEF outputs message K450 KDCFILE generated; KAA-size:nnnK;... in the UTM generation to indicate that the static KAA tables occupy nnn KB. When the application starts, openUTM reads these tables into a memory pool in class 5 memory. The memory pool occupies nnn KB, rounded off to a multiple of 1 MB.

   The inclusion of a user and a terminal results in an additional requirement of (at least) 1 KB. This value increases for “extras” like stacking, TLS, ULS, etc. To allow for the space requirement by extending the configuration, it is better to enter the number of objects with RESERVE statements in the KDCDEF input and let KDCDEF calculate the space requirement itself.

3. Dynamic KAA tables:
   The space requirement for a terminal is at least 1 KB. openUTM first uses the section at the end of the memory pool, which was created for the static KAA tables. If this space is not sufficient, openUTM creates one or more additional memory pools for the dynamic tables in class 5 memory.

4. Cache:
   All processes of a UTM application use the cache as a buffer area for I/Os to the page pool on the KDCFILE. openUTM creates the cache as a memory pool in class 5 memory of the program space, or in one or more data spaces. By creating the cache in a data space, the program space can be released. Location and size of the cache are determined by the KDCDEF parameters MAX CACHESIZE=(number,..., PS | DS) and BLKSIZE=blocksize.

   Example
   If blocksize=2K, its size is number  *  2KB, rounded off to a multiple of 1 MB.

5. KTA tables (KDC Task Area):
   This area contains process-specific administrative data and is created in the class 5 memory. It is at least 8 KB long. The space requirement increases in accordance with the KDCDEF generation parameters.

6. Additional requirement for formatting:
   The code of the format handling system is loaded dynamically. For information on the memory requirement for the format handling system, see the description of FHS. The memory requirement for the formats is added to this.

7. Additional requirement for database system:
   The connection module of the database system can be linked statically or dynamically. The memory requirement can be found in the information for the respective database system.

8. Program units of the user:
   The memory requirement is indicated in the linkage editor list.