--- deprecations: - | The L2 population ``agent_boot_time`` config option is deprecated in favor of the direct RPC agent restart state transfer. It will be removed in the ``Train`` release. critical: - | The neutron-openvswitch-agent can sometimes spend too much time handling a large number of ports, exceeding its timeout value, ``agent_boot_time``, for L2 population. Because of this, some flow update operations will not be triggerred, resulting in lost flows during agent restart, especially for host-to-host vxlan tunnel flows, causing the original tunnel flows to be treated as stale due to the different cookie IDs. The agent's first RPC loop will also do a stale flow clean-up procedure and delete them, leading to a loss of connectivity. Please ensure that all neutron-server and neutron-openvswitch-agent binaries are upgraded for the changes to take effect, after which the L2 population ``agent_boot_time`` config option will no longer be used. fixes: - | The neutron-openvswitch-agent was changed to notify the neutron-server in its first RPC loop that it has restarted. This signals neutron-server to provide updated L2 population information to correctly program FDB entries, ensuring connectivity to instances is not interrupted. This fixes the following bugs: `1794991 `_, `1799178 `_, `1813703 `_, `1813714 `_, `1813715 `_.