Distributed Name Service (DNS) Management Programming Manual

Overview of D-Series Operating System Changes Affecting EMS
Update for D-Series Operating Systems
I–2 46958 Tandem Computers Incorporated
Overview of D-Series
Operating System
Changes Affecting
EMS
You can run distributors and alternate collectors using the TACL RUN command in
the same way on D-series systems as you did on C-series systems. The EMS programs
you wrote for a C-series system can run on a D-series system without modification.
However, to use the extended features of the D-series operating system, you must
become familiar with the new features of D-series systems and convert your EMS
management programs, subsystems, and filter programs to use these features.
This subsection introduces the new features of the D-series operating systems that
affect EMS. If you are already familiar with D-series features, you may wish to skip
this discussion and go to the next subsection, “Summary of Changes to EMS on
D-Series Operating Systems,” which describes new features in D-series EMS.
The enhancements offered by the D-series operating systems that affect EMS users are:
More concurrent processes per CPU
New process identifiers
New object-file attributes
New system procedures
These changes from the C-series to the D-series operating system are described briefly
in this appendix. For more detailed information about the C-series and D-series
operating systems, refer to the following manuals:
GUARDIAN 90 Operating System Application Conversion Guide
D-Series GUARDIAN 90 System Procedure Calls Reference Manual
D-Series GUARDIAN 90 Operating System Programmer’s Guide
More Concurrent
Processes Per CPU
Each EMS event message contains tokens identifying the process reporting the
message. D-series operating systems support more concurrent processes per CPU
than C-series systems; this increased number of processes requires changes in the
tokens identifying a process. A C-series operating system is limited to a maximum of
256 concurrent processes per CPU, while a D-series operating system can support up
to 65,534 concurrent processes.
What Is a PIN?
A process is identified by a process identification number (PIN). When the system
creates a new process, it assigns a PIN to the process. A PIN uniquely identifies a
process on a specific CPU. A C-series PIN has a value in the range 0 through 255.
D-series PIN values range from 0 to the maximum number of processes allowed for
the CPU. There are three types of PINs defined on a D-series operating system:
A low PIN has a value in the range 0 through 254.
A high PIN has a value in the range 256 through the maximum number of
processes allowed for the CPU.
PIN 255 is reserved for use with a synthetic process ID. For more information
about the use of PIN 255, refer to Appendix C in the GUARDIAN 90 Operating
System Application Conversion Guide.