At 02:32 23/04/2007, Christian Schlatter wrote: >Alan, > >Alan Crosswell wrote: >>One option being discussed here is running mysql replicated. This >>brings up the concern that the independent proxies are not aware that >>they are talking to a single database instance. Will there be issues >>involved such as: >>- deadlocks >>- inconsistency of in-memory and in-database data structures >> (e.g. usrloc, presence) >>- collisions of per-proxy unique keys that are inserted into >> tables >>Personally, I think mysql replication violates KISS if I am trying to >>have my redundant servers as independent and survivable as possible. > >With mysql master-slave replication only one proxy could write to the >database, so you'd need master-master replication which is possible but >doesn't offer ACID as mysql cluster does.
I would not constrain oneself, for example one can do symmetric two-way client-server replication. We have done that once with SER, other testimony can be found in http://portal.acm.org/citation.cfm?id=1227865.1228010&coll=&dl=ACM&CFID=15151515&CFTOKEN=6184618 (referring to a Columbia University technical report for even more details). >I agree that using DB replication violates KISS as would also do the >application layer state replication solutions you're describing below. I would say it depends on which type of data you are referring to. With SER (and I would say this is 100% directly applicable to openser too) we have been using different replication strategies to different types of data (tables). >For me the best solution would be to have endpoints registering with all >redundant proxies in parallel. This would also be in-line with SIP's >redundancy in the previous hop. The newest firmware release for the Polycom >SIP phones does support that, though I haven't tested it yet. Are there other >endpoints implementing this feature? The downside is that it does not work once you get a new SIP phone. -jiri -- Jiri Kuthan http://iptel.org/~jiri/ _______________________________________________ Users mailing list [email protected] http://openser.org/cgi-bin/mailman/listinfo/users
