On Fri, Jun 20, 2003 at 06:53:08PM +0200, Stefan Sonnenberg-Carstens wrote: > Hi list, > I'm sure anyone here knows about the linux virtual server (layer 4 load-balancer). > I searched the web for an equivalent for *bsd, but found none. > The only thing which looks like something like a load-balancer is the FreeBSD loadd, > which requires packets to copied from kernel-space to user-space and vice versa. > I know that OpenBSD/pf has some abilities for load-balancing ip packets. > I'd like to know if it goes beyond the round-robin stuff (e.g. schedulars for > least-connection,weighted round-robin), > or if just does that. > I've played arround with load-balancers (F5 BigIP,local director) and would like to > write one for *BSD's, if > there is a demand for that (and to get my hand dirty on code again). > Would it be a good idea to integrate it into a packet-filter (like the lvs) or > implement it as a > stand-alone solution ? >
IMHO the best way to implement that would be to have a load-balancing statement which diverts the initial packet to a userland app. The userland app adds then a correct state in the pf state table and from that point all packets will be automaticaly forwarded via the state table. The user app needs to be smart enough to recognize packages that belong to the same stream. Diversion of packets without a state could be quite useful form many problems that need more handling but are not so simple that a rdr and proxy can solve it. There are also a lot of trapdoors and pitfalls that need cautious planning and a clean implementation. This is on my "cool stuff that I would do if I had time" list since quite a time. -- :wq Claudio
