Scheduling Class and Priority Configuration Support
VCS allows you to specify priorities and scheduling classes for VCS processes. VCS supports the following scheduling classes:
- RealTime (specified as "RT" in the configuration file)
- TimeSharing (specified as "TS" in the configuration file)
- SRM scheduler (Solaris only) (specified as "SHR" in the configuration file)
Priority Ranges
The following table displays the platform-specific priority range for RealTime, TimeSharing, and SRM scheduling (SHR) processes.
| Platform
| Scheduling Class
| Default Priority Range
Weak / Strong
| Priority Range Using #ps Commands
|
|---|
AIX
|
RT
TS
|
126 / 52
60
|
126 / 52
Priority varies with CPU consumption.
Note On AIX, use #ps -ael
| |
HP-UX
|
RT
TS
|
127 / 0
N/A
|
127 / 0
N/A
Note On HP-UX, use #ps -ael
| |
Solaris
|
RT
TS
SHR
|
0 / 59
-60 / 60
-60 / 60
|
100 /159
N/A
N/A
Note On Solaris, use #ps -ae -o pri, args
|
Default Scheduling Classes and Priorities
The following table lists the default class and priority values used by VCS. Note that the default priority value is platform-specific. Therefore, when priority is set to 0, VCS converts the priority to a value specific to the platform on which the system is running. For TS, the default priority equals the strongest priority supported by the TimeSharing class. For RT, the default priority equals two less than the strongest priority supported by the RealTime class. So, if the strongest priority supported by the RealTime class is 59, the default priority for the RT class is 57. For SHR (on Solaris only), the default priority is the strongest priority support by the SHR class.
| Process
| Default Scheduling Class
| Default Priority
| | AIX
| HP-UX
| Solaris
|
Engine
|
RT
|
52 (Strongest + 2)
|
2 (Strongest + 2)
|
57 (Strongest - 2)
|
Process created by Engine
|
TS
|
60
|
N/A
|
60 (Strongest)
|
Agent
|
TS
|
60
|
N/A
|
0
|
Script
|
TS
|
60
|
N/A
|
0
|
|
