Information About Cisco Ios Xr Process Placement - Cisco NCS 6000 Series Configuration Manual

Information About Cisco IOS XR Process Placement

You must be in a user group associated with a task group that includes the proper task IDs. The command
reference guides include the task IDs required for each command. If you suspect user group assignment is
preventing you from using a command, contact your AAA administrator for assistance.
Information About Cisco IOS XR Process Placement
What Is a Process?
To achieve high availability and performance, the Cisco IOS XR software is built on a modular system of
processes. Each process provides specific functionality for the system and runs in a protected memory space
to ensure that problems with one process cannot impact the entire system. Multiple instances of a process can
run on a single node, and multiple threads of execution can run on each process instance.
Under normal operating conditions, processes are managed automatically by the Cisco IOS XR software.
Processes are started, stopped, or restarted as required by the running configuration of the router. In addition,
processes are checkpointed to optimize performance during process restart and automatic switchover.
What Is Process Placement?
Process placement is the assignment of placeable processes to specific locations, such as an installed in the
router.
Placeable processes include all routing processes, such as Open Shortest Path First Protocol (OSPF), Border
Gateway Protocol (BGP), and multicast routing.
Default Placement Policy
In a new system, processes are distributed according to their affinity values among the available nodes and
node pairs in a .
Note The default process policy that is shipped on the system upon startup is suitable for general purposes.
While customizing is possible, there is no requirement to change the process placement. If you believe
the a change is required, you should work closely with Cisco personnel to ensure that the impact to your
system is contained to just an instance of a process to avoid any undesirable results.
Following is the default placement policy:
• Processes have a preference to run on paired nodes (nodes that have an associated standby node).
• Processes have a preference to remain on their current node. Therefore, processes do not move
• When a new node pair is added, the following rules apply:
System Management Configuration Guide for the Cisco NCS 6000 Series Router, Release 5.0.x
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automatically, unless the unpaired node (or both nodes in a node pair) on which they are running fails.
If the node fails, and there is no standby node, the processes are restarted on a different node.
◦ The currently running processes are not automatically moved to the new cards.
Process Placement