ovn-controller is taking lot of time to release port bindings if all these port bindings are 

tracked in one engine run.

2024-11-25T16:55:31.536Z|11341|inc_proc_eng|INFO|node: physical_flow_output, handler for input runtime_data took 920ms

—

The function 
physical_multichassis_reprocess() [1] is the culprit here. 

If suppose a logical switch has 'N' logical ports and all these 'N' logical ports are bound on a chassis 'CH1' and if all the ovs ports are deleted and are handled in one engine run, then the above function iterates through all these 'N' logical ports (port bindings) N times  ( O(N * N))

Steps to reproduce
-------------------------

1. Start OVN with the attached ovnnb_db.db  (a  single node is good enough)

2. Get the names of all the logical ports of the logical switch m42-h15-000-r760

   ovn-nbctl show m42-h15-000-r760 | grep port | grep -v stor | grep -v rtos | awk '{print $2}' > ports.txt

3.  Bind all these ports in the chassis by creating ovs ports in one transaction.

-----------------------------------------
#!/bin/bash
set -x
n="p"
i=1
ovs_cmd=""
for p in $(cat ports.txt)
do
  echo $p
  echo $i
  iface_id=$p
  name="p${i}"
  cmd=" – add-port br-int $name  -- set Interface $name external_ids:iface-id=$iface_id – set Interface $name type=internal "
  i=$((i+1))
  ovs_cmd="${ovs_cmd}${cmd}"
done

ovs-vsctl $ovs_cmd
-----------------------------------------

Run the above script.

4. Delete all the ovs ports in one transaction and monitor the ovn-controller.log

-----------------------------------------
#!/bin/bash
set -x
n="p"
i=1
ovs_cmd=""
for p in $(cat /data/ports.txt)
do
  echo $p
  echo $i
  iface_id=$p
  name="p${i}"
  cmd=" – del-port $name "
  ovs_cmd="${ovs_cmd}${cmd}"
  i=$((i+1))
done

ovs-vsctl $ovs_cmd
-----------------------------------------

Repeat creating and deleting the ovs ports.

You'd see deleting ports taking more time.

See the corresponding OCP issue for more details - https://issues.redhat.com/browse/OCPBUGS-37825

And the customer case - https://access.redhat.com/support/cases/#/case/03868814

 [1]- https://github.com/ovn-org/ovn/blob/main/controller/physical.c#L2437