For an optimal usage of multiprocessor configurations, ADABAS supports an external/internal tasking that can be configured. The aim hereby is to support as many database sessions as possible with a minimum number of operating system processes. One operating system process is required for each CPU that resides in the computer and is to be used by an ADABAS serverdb.
The degree of the external/internal tasking is controlled by the two configuration parameters MAXUSERTASKS and MAXCPU.
The parameter MAXUSERTASKS indicates the maximum number of simultaneously active users (database sessions). Overconfiguration exceeding the actual requirements results in increased address space (especially shared memory) requirements.
The parameter MAXCPU indicates the number of CPUs to be made available to the serverdb.
For example, if you want to use up to 800 simultaneously active database sessions on a 4-processor computer, MAXUSERTASKS must be set to 800 and MAXCPU to 4. The serverdb can then utilize the four processors by establishing four operating system processes each of which performs an internal tasking for up to 200 users.
If the number of configured database sessions is exhausted, no other user can connect to the serverdb. The number of active sessions is therefore a critical parameter of database operation and must be monitored.