We've recently discovered a defect that affects users of High Availability (HA) who also have multithreading (MT) enabled, running on Kea 1.8 (stable) and 1.9 (development). Multithreading is disabled by default, so if you have not explicitly configured to run your Kea servers with MT, you are unaffected.
The problem uncovered is that the HA server pairs do not add or update IPv4 leases on their partner systems when MT is in use. A server that handles a 'lease4-update' logs success, but without actually adding or updating a lease on systems that are running with MT enabled. In an HA environment, lease4-update is used for ongoing lease updates (send-lease-updates is true). This problem therefore does not affect production environments that use another mechanism for updating leases between Kea servers (such as a shared lease backend). Initial lease database synchronisation (sync-leases is true) does not use lease4-update so it is also not affected. In addition, administrator operation of the lease4-update command falsely reports success. Disabling MT is an effective workaround that allows HA server pairs to continue to share lease updates. We will be fixing this defect in Kea 1.8.2 (no ETA yet) and 1.9.2 (November 25). Details and a source-code patch (1.9 branch) can be found here: https://gitlab.isc.org/isc-projects/kea/-/issues/1542 Cathy Almond ISC Support _______________________________________________ ISC funds the development of this software with paid support subscriptions. Contact us at https://www.isc.org/contact/ for more information. To unsubscribe visit https://lists.isc.org/mailman/listinfo/kea-users. Kea-users mailing list [email protected] https://lists.isc.org/mailman/listinfo/kea-users
