Messages in this thread | | | From | "Russell Coker - mailing lists account" <> | Date | Thu, 02 Oct 97 07:50:58 +1100 | Subject | Re: Process Migration on Linux - Impossible? |
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>>>> So you want fault tolerance, not process migration. Don't confuse the >>>> technique with the result. >>> >>> That's an odd thing to say, isn't it? Re-read my first sentence again, >>>carefully this time. If one can throw a process on another machine at will, >>>it becomes trivial to checkpoint, yes? Fault tolerance for free. >> >> Nope. Not so. You can't migrate a TCP/IP connection between machines even
>I've been wondering about that. It would seem possible if the machine that >receives the proces (let's call it B) is on the same net with ethernet. B >would put it's card in promiscuous mode, and listen for packets that are >meant for the port/ip adress of the application. The machine the process >comes from (A) would stop responding to packets for that process. As long >as the router accepts answers coming from the ethernet-adress of B >(encapsulating perfectly good IP packets that are ok for the rest), it >would seem that in fact B could >take over A's network connection. A and B can compare notes ever so often >to see whose card can best be put in promiscuous mode (maybe even both if >there's also processes from B on A).
You could even use IPv6 and have a unique IP address for every process which uses the network and is a candidate for migration (many things such as NFS client daemons are not candidates for migration...).
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