Process-level redundancy is implemented by a system manager process that creates the standby
process. What two functions are provided by the system-level process called Qnet Symlink
Manager (QSM)? (Choose two.)

A.
backing up the information for the broken connections

B.
provides common information for connecting processes and services

C.
detection of a failed connection

D.
provides an abstract name for a process or service

E.
distribution of symbolic link information

Explanation:
1.4. SP high end product
1.4.01. IOS-XR structure
Process-Level Redundancy
Process-level redundancy is implemented by a system manager process creating the standby
process.
Because the active process created the standby process, the active process has all the
information that it needs to communicate with the standby process. The active process uses a
checkpoint database to share running state with the standby process. Symbolic links and abstract
names are used to identify the processes.
Clients do not see the standby process until the active goes away. If a process fails and it has
created a standby process, a system-level process called QNet Symlink Manager (QSM) and a
library called Event Connection Manager (ECM) are used to re-establish links from the clients to
the processes.
QSM provides:
Distribution of symbolic link information

Abstract name for a process or service
ECM provides:
Common information for connecting processes and services
Detection of broken connections
Only processes considered essential by development engineers are designated to support
process-level redundancy. This is not a user-configurable option.
Clients have to reconnect to the “new” active process (the “original” standby process) when they
detect that the active process has failed. Clients can connect to it using the symbolic links and
abstract names. The new active process creates a new standby process.
The general steps in process redundancy are:
The active process dies.
The standby process becomes the active process.
A new standby process starts.
The new active process begins sending updates to the new standby process.
Clients begin using the new active process through the symbolic links and abstract names.