Tilghman Lesher wrote: > On Friday 09 January 2009 13:52:56 Anthony Francis wrote: > >> Tilghman Lesher wrote: >> >>> We are entirely interested in DETERMINISTIC methods of uniqueness, not >>> random and hope-for-the-best. Given a truly random generator, it is >>> possible for the same number to come up 100 times in sequence. That is >>> part of what random means. It may be statistically unlikely, but it is >>> just as likely as any other sequence. When it comes to fragility, using >>> a random number for a UUID is NOT deterministic and MAY produce >>> collisions. >>> >> I may be over simplifying but I would have a serial number object that >> gets incremented anytime it is called and will be set to 0 at start-up. >> I would then use it to generate a UUID like this: >> MAC.serialid.64bit timedate >> >> Not only would this number be perfectly universally unique (as long as >> you dont falsify the MAC) but from a record standpoint it gives you >> easily parsable information in a single field, the id of the call for >> referential integrity, the machine that generated the uuid, the calls >> created since start at the time of the call creation, and the exact time >> of creation with microseconds. >> > > Of course, one of the problems comes in with: what do you do for machines > which don't have a MAC address? We've been approached by individuals who > use virtualized network addresses and don't have direct access to their MAC > address (which is somewhat important for things like G729 licenses). What do > you do for them? > > In cases of virtualization, at least in xen you can give a virtual machine access to a physical card, if not, then fake it using a fake mac address on each virtual machine in the research range of addresses, after all, you only really care about not conflicting with UUIDs in your own system.
Anthony _______________________________________________ -- Bandwidth and Colocation Provided by http://www.api-digital.com -- asterisk-users mailing list To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users
