Reasons To Change The Default Process Placement - Cisco NCS 6000 Series Configuration Manual

Process Placement

Reasons to Change the Default Process Placement

Although the default process policy that is shipped on the system upon startup is suitable for general purposes,
changes to the router configuration can result in the need for processes to be rebalanced among the available
CPU and memory resources.
When a system is initially booted, the system assumes that all processes use the same amount of memory,
thereby treating each process as equivalent. As the configuration grows, however, the CPU load and memory
requirements of some application processes increase. Centralized applications may need a larger portion of
the resources.
In addition, when a new is added to a system, only new processes or process instances are added to the node.
This could result in some processes with too few resources, while the newer cards are underutilized.
Therefore, as the software configuration changes, or hardware is added, it may become necessary to rebalance
processes among the available in .
Reoptimizing Process Placements
The easiest and most reliable method for users to redistribute processes among the available in is with the
placement reoptimize command.
During router operation, the actual resource usage of each process is collected and compared to the router
configuration and network topology. An ideal configuration for process placement is created and updated in
real time.
To implement this ideal process placement configuration, enter the placement reoptimize command in
EXEC mode. Before the changes are made, the system displays a summary of the predicted changes. You
can either accept the changes or cancel the operation.
See Reoptimizing Process Placement, on page 11
Reconfiguring Process Placements
You can also change the process placement affinities, or preferences, to override the default policies. For
example, you may learn that some processes perform better on the primary node pair, or that some processes
have better high-availability characteristics when running on a paired node (a node with a standby partner).
Other processes might benefit from co-location or by being assigned to nodes far apart from each other.
Consult with your technical support representative before changing the default process placement
Note
configuration. Incorrect configurations can cause system error, poor performance or downtime.
◦ The general preference is for new processes (such as a new ISIS instance) to start on the new node
pair, which contains the most available CPU and memory resources in the system.
◦ Other affinity settings may override the general preference. For example, if the IS-IS process has
a strong affinity to run on the same node where ipv4_io is running, then IS-IS would be started on
that node, and not the new node-pair.
System Management Configuration Guide for the Cisco NCS 6000 Series Router, Release 5.0.x
Reasons to Change the Default Process Placement
for detailed instructions.
9