Messages in this thread |  | | Date | Fri, 1 Nov 1996 14:23:27 -0800 (PST) | From | Jauder Ho <> | Subject | Re: mirrored machines via network |
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Try looking at Auspex's ServerGuard.
--Jauder
On Fri, 1 Nov 1996, James R. Leu wrote:
> First off please let me apologize for my lack of kernel programming > knowledge, this is my first venture into kernel space. My basic goals of > this letter are 1) a reality check and 2) to obtain a list of resources of > where to look or what to read to get me started. > > As my title below states I'm in charge of administrating all the network > operations of a small ISP. I am looking into ways of implementing redundant > servers. By this I mean two machine that are exactly the same as far > as services provided, and data stored. There only deviation would be the > IP address assigned to it. My example will hopefully reveal why I want to > achieve this. > > 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 > address. The second of which is the "mirrored machines via the network". > Because of my limited knowledge of kernel I/O I'm not really sure how to > implement such a driver/service. My initial looks into the I/O subsystem led > me into the drivers/block directory of the Linux kernel source. I look at hd.c > and could understand what was happening, but I don't understand how it fits in > to the whole scheme of things. > > The best way to illustrate how the entire system would work would be to give an > example. I will refer to the primary machine as machine A, and the backup > machine as machine B. There is at least a third machine on the network, and > this operates as the primary DNS for the network. Under normal situations > (ie no failed hardware, no kernel panics :o) machine A response to all WWW > services all e-mail services, and all authentification requests and usage > accounting (via RADIUS). The machine also serves shell logins. During this > time machine B needs to constantly be updates to account for changes in web > pages, changes in passwords, in general all changes to the file system on A need > to be duplicated on B. The reason it needs to be duplicated arises when > machine A blows up. At this time the primary name server would notice that > machine A is not responding correctly. It would switch its internal tables for > machine A and now point them to machine B. > > I do realize there are many areas that need to be worked out. The least of > which is how to determine if a machine is no longer responding, but I hope with > some input from this community, to be able to overcome each problem and form > a truly reliable solution. I welcome all responses/tips/hints/flames. > > Last but not least, if anyone has seen this or anything similar, please let me > know. I looked long and hard for something similar, but I'm sure my search > was not entirely exhaustive. Also I know my view of this may be naive, so > please do enlighten me. > > James > -- > James R. Leu > Network Administrator > CORE Digital Communication Services > jleu@coredcs.com >
.sig under construction
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