Messages in this thread |  | | Date | Wed, 06 Nov 1996 10:27:55 +0000 | From | Timothy Peters <> | Subject | Re: mirrored machines via network |
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Peter Rival wrote: > > -----BEGIN PGP SIGNED MESSAGE----- > > On Mon, 4 Nov 1996, Ian Main wrote: > > On Fri, 1 Nov 1996, Ray Lehtiniemi wrote: > > >On Fri, 1 Nov 1996, James R. Leu wrote: > > >> operations of a small ISP. I am looking into ways of implementing redundant > > >> servers. > > >[snip] > > >> The idea I have, necessitates two main developments. The first of which is > > >> a "intelligent" name-server. I have begun development of this already. I have > > >> started by using th bind-4.x.x source. The end result will hopefully be a > > >> name-server that checks if a machine is responding, before it gives out the IP > <snip simplification reasoning> > > ping master > > if no response ifconfig eth0 down > > ifconfig eth0 <master_ip> up > > > > so long as they're on the same subnet, it should work no? > > Yes, it (could) work. However, I see two potential probs with that > idea. One - how do you decide how often (and how much) to ping the master? > Granted ICMP echo requests aren't all that large for packets, but in this day > and age, we need all the spare bandwith we can get. And two - what happens if > you lose the entire segment? (I know, scream bloody murder and turn on the > coffee pot...;) If you could set up the master DNS server to check on the > state of the server (I think the newest version of lbnamed does this) before > returning the IP, you could put them on separate segments and hopefully have > a little more redundancy. > > > Now all you have to deal with is dropped connections, and the mirroring of > > the HD. > > Well, that's where this idea kinda falls apart. Unless you can write > some really schnazzy clustering software that works _reliably_ through a > router. I know there are things out there like this...unfortunately, I've > gotta go install an AIX (eeww...hate that word) box, so I don't have the time > to try to research it. Quick thought - Auspex does do something like this, > but I don't think it solves the separate segment thing. > > - Pete > > -----BEGIN PGP SIGNATURE----- > Version: 2.6.2 > > iQCVAwUBMnvMHjkUd9WlV5D5AQFYmwP/UQoFYzBFQJigdlpQecj4Ns6n9Z5aRaba > +JKuZW9kuxnJktpZUMjz4YAiHbpHIsbct19/055FilWSPuGdwsM3AOIILRb7IkTE > nbp98a2R40uxb2cgoOHlsXdei7rNgdBzcps+dibdpRMZBetJQQ+PCVSn6BxXd+cF > 3n9cMD/wNBU= > =+cLp > -----END PGP SIGNATURE----- This situitation is something taht i will be looking into as part of my research project what I hope to have is two machines which will share a common memory image (don't ask how I don't know yet :-) ). So that if one fails the other can assume it responsabities. -- Timothy Peters Senior Software Engineering Techinician School of Engineering & Technology Nene College St Georges Ave Northampton NN2 6JD (01604) 735500 Ext. 3112 tim.peters@nene.ac.uk
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