[ https://forge.continuent.org/jira/browse/SEQUOIA-918?page=comments#action_14602 ]
Emmanuel Cecchet commented on SEQUOIA-918: ------------------------------------------ UDP multicast should be as reliable as UDP unicast on a LAN. I don't see any reason why we couldn't use the same approach as the current one by replacing UDP unicast with UDP multicast. The win would be that if multiple clients try to access the same vdb, we could reduce the amount of ping/pong traffic to one multicast ping for all clients and one pong per controller (instead of nb_of_clients*nb_of_controllers ping/pong messages). The frequency of multicast messages will have to be the same as the one of ping messages, or more lazily when a timeout is noticed a client sends a new ping message to confirm that a controller is dead. > Driver pinger may break in configuration with multiple interfaces > ----------------------------------------------------------------- > > Key: SEQUOIA-918 > URL: https://forge.continuent.org/jira/browse/SEQUOIA-918 > Project: Sequoia > Type: Bug > Components: JDBC Driver > Versions: Sequoia 2.10.4, Sequoia 3.0 beta3, Sequoia 2.10.5, Sequoia > 2.10.6, Sequoia 2.10.3 > Reporter: Marc Herbert > Assignee: Gilles Rayrat > > > The driver pinger currently identifies answering controllers by looking at > the source address of the pong answer packet. If the controller has multiple > network interfaces, it may return the "Pong" packet using an address unknown > to the driver, breaking the ping scheme. > One fix would be to use UDP on _connected_ sockets. But connected sockets is > probably overkill and a resource waste. > This seems to be a simpler fix: the driver sends a controller ID to the > controller, and the controller just returns it. (this controller ID can be > private to the driver) > It should be possible to implement this in a backward compatible way. -- This message is automatically generated by JIRA. - If you think it was sent incorrectly contact one of the administrators: https://forge.continuent.org/jira/secure/Administrators.jspa - For more information on JIRA, see: http://www.atlassian.com/software/jira _______________________________________________ Sequoia mailing list [email protected] https://forge.continuent.org/mailman/listinfo/sequoia
