[neutron] qrouter namespace missing in controllers - opensack ussuri

Hi Team We are experiencing an issue of reachability in some of the projects, instances in the project are not reachable. It is a project specific issue. I tried to check router details and could observe . For the project having issues, I checked the router and could see that the qrouter namespace is not present in the command "ip netns" in any of the controllers. Problem started after a reboot of one controller. Do any one has faced a similar issue and any suggestions to recover this? Regards Keshav Bareja