On Tuesday 30 September 2008, Daniel-Constantin Mierla wrote: > > [..] > > Sure, it's great if my registrants always go to the same location > > server, but if 90% of my users end up going to one location server > > because of the distribution that the variance of their From URIs > > provides, what does this really give me except a predictable route? > > It's not as if I can use the hash to "find" a user's location server > > -- unless the location server was determined using the same hash also. > > What's the point? > > The hash function was tested to get pretty fair distribution for AoR, > most of the hashed values respect this format. If 90% of your users end > up to same server, then you may need to code a bit :-) and add an > alternative hash function to the module. For me the existing one seems > good so far. > > I do not need to know where a user call is going. Practically, they > could share the same db backend for auth, but the location and other > user profiles details may be in memory for speed purposes. In what I am > doing, all the servers in a group have same config, if i add a new one, > I get a new dispersion of the users across servers. > > Getting the distribution is quite simple, take the has function and make > a simple app that takes as parameter a string and outputs the hash > value. Knowing your subscriber base ids, you can estimate the results of > dispatching.
Hi Alex, don't that much about the dispatcher internals, but i think it also uses the CRC32 hash. In my tests with the carrierroute module that uses this too, requests over a random callid/ from user are distributed equally with about +/- 5% accuracy, which i think is ok. If you need to adjust the target host distribution, take a look at the hash_id functionality (carrierroute config file mode), here you can specify the exact destination. We use also the this approach of pre-calculating the hash value that Daniel described. Cheers, Henning _______________________________________________ Users mailing list Users@lists.kamailio.org http://lists.kamailio.org/cgi-bin/mailman/listinfo/users
