Setting operating system scheduling priority

The scheduling priority is equivalent to the nice command in UNIX. It sets the execution priority for a process, which determines in what order the operating system runs processes.

Priority range

In general, the priority range spans from 0 to 20. However, different operating systems interpret these values differently.

UNIX, OS\2

The lower the value, the higher the priority (faster execution). To raise the priority of the agent to high, you must enter a negative number. However, raising the priority to high is not advisable because it uses significantly more system resources and can cause other applications to crash.  The following list provides the ranges of values of priority:

• 11 to 20 low priority
• 0 to 10 normal priority
• -1 to -15 high priority

These systems have a default process priority. The PATROL priority is added to the default priority to determine the agent's process priority on the OS.

default process priority + agentPriority = agent process priority on the OS

Windows

This configuration variable affects the priority of the agent process on the Windows platform. The agent's default priority is normal. To change the agent process's priority, you must use the Windows Task Manager. 

Windows priorities in order of highest to lowest are:

• Realtime
• High
• Normal
• Low

In addition, Windows 2000 offers priorities of AboveNormal and BelowNormal. 

To set the priority for the PATROL Agent, specify ranges for the /AgentSetup/AgentTuning/agentPriority variable as prescribed in the following list:

• 11 to 20 low priority
• 0 to 10 normal priority
• -1 to -15 high priority

OpenVMS

The higher the value, the higher the priority (faster execution). The current process's priority is the default priority.

On Alpha

Priorities range from 0 to 63, where 63 is the highest.

• 0 -15 are normal priorities
• 16 -63 are real-time priorities

On VAX

Priorities range from 0 to 31, where 31 is the highest.

• 0 -15 are normal priorities
• 16 -31 are real-time priorities

For PATROL Agent

The /AgentSetup/AgentTuning/agentPriority configuration variable specifies the operating system scheduling priority for the PATROL Agent process.

For processes created by PATROL Agent

The /AgentSetup/AgentTuning/userPriority configuration variable specifies the operating system scheduling priority for processes created by the PATROL Agent. These processes are external processes that the agent spawns from the main run queue.

For cache refresh process

The /AgentSetup/AgentTuning/procCachePriority configuration variable specifies the operating system scheduling priority for the process that refreshes the process cache.

For internal cache refresh process

The /AgentSetup/AgentTuning/procCacheSchedPriority configuration variable specifies the Internal PATROL Agent scheduling priority for the process that refreshes the process cache.