Round Robin
Mark_Andrews at iengines.com
Mark_Andrews at iengines.com
Thu Nov 25 23:28:33 UTC 1999
The long term solution to this is to write a draft stating
how to use SVR records with FTP. SVR records are ideally
suited for this situation.
The trick below will work though it does consume address
space.
You can also create 11 CNAME records for ftp.example
ftp.example CNAME ftp1.example
ftp.example CNAME ftp2.example
...
ftp.example CNAME ftp10.example
ftp.example CNAME ftp11.example
ftp1.example A <main_server>
...
ftp10.example A <main_server>
ftp11.example A <backup_server>
If you do this make sure you have an up to date (8.2.2-P5)
version of BIND for all the servers for this zone. We
introduced a bug in the handling of multiple-cnames around
8.1.2/8.2. You also need to turn on multiple-cnames in
the options block for all thse servers. This solution has
the drawback that if the ftp client is willing to try all
the addresses it is given you won't get automaitic failover.
You can alleviate this bu making ftp1.example have both
address ftp1 to ftp10 having main_server first and
backup_server second, ftp11 having the reverse order and
setting rrset-order for these records (not ftp.example) to
fixed on all the servers.
There are also commerial products from the will do this
sort of thing. CISCO makes a product as do others. Go
to deja.com and perform an advanced search in the forum
comp.protocols.dns.bind where bind-users is gatewayed to
find other vendors.
Mark
> As bind ignores duplicate records
> eg
> dreamer IN A x.x.x.x
> dreamer IN A x.x.x.x
> and thus it is impossible to load balance based on the specs of individual ma
> chines, would
> proportionally multi homing a machine and thus having many records with diffe
> ring ip
> addresses to balance it out?
> eg
> machine one, daul athlon 800 2gig ram (main ftp server)
> assign this machine ten ips
> machine two, p200 128 ram (extra server)
> assign this one ip
>
> then list A records for all ten ips and thus make machine one ten times more
> frequently
> accessed than machine two.
> Is this a viable trick or is there a better way to implement load balancing?
> cheers
> --
> Marek Narkiewicz, Webmaster Intercreations
> Reply to <-marek @ intercreations . com->
> "Ticking away, the moments that make up a dull day"
> Pink Floyd
> Time
>
>
--
Mark Andrews, Internet Engines Inc. / Internet Software Consortium
1 Seymour St., Dundas Valley, NSW 2117, Australia
PHONE: +61 2 9871 4742 INTERNET: Mark_Andrews at iengines.com
More information about the bind-users
mailing list