Contents

Introduction

Background Information

Problem

Solution

Introduction

This document describes Standby UPF Session Manager tasks lacking socket connection to corresponding rcm-checkpointmgr pods in RCM-based deployment.

Background Information

This document addresses occasional Standby User Plane Function (UPF) Session Manager tasks which have Socket Ready issues; lacking socket connection to corresponding rcm-checkpointmgr pods in Redundancy Configuration Manager (RCM)-based UPF deployment.

Problem

In Standby UPF, Session manager task instance 10 has no socket connection to rcm-checkpointmgr pod.

[local]UPF# show rcm checkpoint statistics verbose

smgr     state  peer    recovery  pre-alloc  chk-point rcvd   chk-point sent

inst            conn    records   calls      full     micro   full     micro

----   -------  -----   -------   --------   -----    -----   -----     ----

1      Stby Ready         0          0       0        0       0        0

2      Stby Ready         0          0       0        0       0        0

3      Stby Ready         0          0       0        0       0        0

4      Stby Ready         0          0       0        0       0        0

5      Stby Ready         0          0       0        0       0        0

6      Stby Ready         0          0       0        0       0        0

7      Stby Ready         0          0       0        0       0        0

8      Stby Ready         0          0       0        0       0        0

9      Stby Ready         0          0       0        0       0        0

10      Stby               0          0       0        0       0        0

11      Stby Ready         0          0       0        0       0        0

12      Stby Ready         0          0       0        0       0        0

13      Stby Ready         0          0       0        0       0        0

14      Stby Ready         0          0       0        0       0        0

15      Stby Ready         0          0       0        0       0        0

16      Stby Ready         0          0       0        0       0        0

17      Stby Ready         0          0       0        0       0        0

18      Stby Ready         0          0       0        0       0        0

19      Stby Ready         0          0       0        0       0        0

20      Stby Ready         0          0       0        0       0        0

21      Stby Ready         0          0       0        0       0        0

22      Stby Ready         0          0       0        0       0        0

Solution

Current Workaround :

- To address the socket communication issue between Standby UPF Session Manager and its rcm-checkpointmgr pod:

- Log in to the corresponding Standby UPF.

- Enter debug mode (cli test-commands password <password>).

- Execute 'task kill facility sessmgr instance <instance-id>' for the affected session manager task without a socket connection to rcm-checkpointmgr.

- Wait for a minute, then verify that the Session Manager task now has a stable socket connection in the Ready state.

- If the issue persists, consider rebooting the Standby UPF and recheck after the UPF is fully operational.

Permanent Fix:

- You can explore implementing TCP hardening feature in your deployment. This feature introduces a Heartbeat mechanism between Session Manager tasks and rcm-checkpointmgr pods, ensuring the socket connection is re-established as needed. For details, refer to Redundancy Configuration Manager -Configuration and Administration Guide, Release 2022.04 .