Hello, I have a long-standing issue with L3 Agent which I would like to finally solve - *very* slow router provisioning in L3 Agent. We are operating a Rocky-based OpenStack deployment with three bare-metal L3 Agent nodes running in legacy mode. After restarting the L3 node, it takes a really long time for the L3 agent to become fully operational. There are two parts of resync which take much time: getting a list of routers from neutron-server and actually recreate them in the L3 node. While the long running time of router list retrieval is somewhat understandable, the router provisioning process itself proves to be very troublesome in our operations tasks. In our production deployment with around 250 routers, it takes around 2 hours (!) to recreate the router namespaces and have the L3 node fully functional again. Two hours of router re-provisioning is actually an optimistic scenario, this proved to be much longer during the outages we encountered (sometimes the sync took nearly 6-8 hours). This effectively prolongs any maintenance upgrades, configuration changes and OpenStack release upgrades. Another thing is, on that same production environment the first 100 routers usually get provisioned fast (around 30 minutes), after that it slows down with each router - this kind of non deterministic behavior makes it hard to communicate the maintenance finish ETA for our users. We also have a test environment with Stein already installed, where this problem is also present - full resync of 150 routers, with only one external gateway ports, takes around an hour to complete. Are there any operators here who also encountered that issue? Does anyone have any experience with similar situation and are willing to share their observations and optimizations? -- Regards, Patryk Jakuszew