R0106-HP MSR Router Series High Availability Configuration Guide(V7)

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The system provides a default process placement policy that takes effect for all processes. You can modify
the default placement policy in the view you enter with the placement program default command. You
can also configure a placement policy for a specific process in the view you enter with the placement
program program-name [ instance instance-name ] command. A placement policy for a process takes
precedence over the default process placement policy.
By default, the default process placement policy defines the following rules:
• The active process runs on the main CPU of the active MPU, and the standby processes run on other
CPUs.
• A process runs at the location where it ran the last time and does not move to any other location
during startup or operation.
• The addition of a new node does not impact current active processes. A new active process selects
one node with sufficient CPU and memory resources. (You can use the display cpu-usage and
display memory commands to view CPU and memory usage information.)
Optimizing process placement
You can configure the following settings for a process placement policy to optimize process placement:
• affinity location-set—Location affinity, the preference for the process to run on a specific node.
• affinity location-type—Location type affinity, the preference for the process to run on a particular
type of node. For more information about node types, see "Configuring a location type affinity."
• af
finity program—Process affinity, the preference for the process to run on the same node as a
particular process.
• affinity self—Self affinity, the preference for one instance of the process to run on the same node as
any other instance of the process.
Affinities include positive affinities (attract) and negative affinities (repulse), all represented by integers
in the range of 1 to 100000.
• The higher the attract value, the stronger the preference.
• The higher the repulse value, the weaker the preference.
After you apply new placement policies, the system makes placement decisions based on the new
policies, node resources, and topology status. If the new location for an active process is different from
the current node, the system changes the state of the process to standby, and uses the standby process on
the preferred location as the new active process.
Configuration restrictions and guidelines
• Configuring process placement on a device with only one CPU does not change the location of
processes.
• Configuring process placement on a device with multiple CPUs places specific active processes to
specific CPUs. In case of multiple CPUs, the system performs 1:N process redundancy, where N
must be less than the number of CPUs. The number of standby processes and their CPU locations
depend on the function module. The system by default automatically determines the location for
each active process, and there is no need to optimize process placement. If optimization is needed,
work with HP engineers to avoid service interruption.
• Process placement applies to MPUs only. The configuration does not take effect on an interface card
even if it has a CPU and is configured as location affinity for a process.