nanog mailing list archives
anycast (Re: .ORG problems this evening)
From: "E.B. Dreger" <eddy+public+spam () noc everquick net>
Date: Thu, 18 Sep 2003 18:01:07 +0000 (GMT)
Date: Thu, 18 Sep 2003 13:47:01 -0400 From: Keptin Komrade Dr. BobWrench III esq.
And, I might add, in the case of a highly complex anycast application, you will need to check not only for correctness, but for timeliness.
In a realtime system, something that is late is considered incorrect. A DNS response that arrives after three seconds is unsat, and (from a RT perspective) incorrect. I should have been more clear in my wording.
And, again, in the case of a highly complex app such as an anycast DNS, you need to check several behind the scenes apps, such as maybe a db, the responsivness of your high avail partner server, the dns daemon, connectivity through two or more network paths, connectivity to master update servers, BGP on whatever boxes are providing BGP, etc, the list goes on.
Yes on all counts, except perhaps connectivity... BGP handles that. If you mean killing the link in case of saturation, I'd argue that's a bad idea -- that just means the large traffic quantity will go elsewhere.
But again, that's just my opinion, I could be wrong. ;-)
That's why one uses a daemon with main loop including something like: success = 0 ; for ( i = checklist ; i->callback != NULL ; i++ ) success &= i->callback(foo) ; if ( success ) send_keepalive(via_some_ipc_mechanism) ; The BGP mechanism listens for keepalives via the IPC mechanism. Eddy -- Brotsman & Dreger, Inc. - EverQuick Internet Division Bandwidth, consulting, e-commerce, hosting, and network building Phone: +1 785 865 5885 Lawrence and [inter]national Phone: +1 316 794 8922 Wichita _________________________________________________________________ DO NOT send mail to the following addresses : blacklist () brics com -or- alfra () intc net -or- curbjmp () intc net Sending mail to spambait addresses is a great way to get blocked.
Current thread:
- Re: .ORG problems this evening, (continued)
- Re: .ORG problems this evening Todd Vierling (Sep 18)
- Re: .ORG problems this evening Leo Bicknell (Sep 18)
- Re: .ORG problems this evening Todd Vierling (Sep 18)
- Re: .ORG problems this evening David Lesher (Sep 18)
- Re: .ORG problems this evening E.B. Dreger (Sep 18)
- Re: .ORG problems this evening Todd Vierling (Sep 18)
- Re: .ORG problems this evening E.B. Dreger (Sep 18)
- Re: .ORG problems this evening bmanning (Sep 18)
- Re: .ORG problems this evening E.B. Dreger (Sep 18)
- Re: .ORG problems this evening Keptin Komrade Dr. BobWrench III esq. (Sep 18)
- anycast (Re: .ORG problems this evening) E.B. Dreger (Sep 18)
- Re: anycast (Re: .ORG problems this evening) E.B. Dreger (Sep 18)
- Re: anycast (Re: .ORG problems this evening) Todd Vierling (Sep 18)
- Re: anycast (Re: .ORG problems this evening) David G. Andersen (Sep 22)
- Re: anycast (Re: .ORG problems this evening) Patrick (Sep 22)
- Re: anycast (Re: .ORG problems this evening) E.B. Dreger (Sep 22)
- Re: anycast (Re: .ORG problems this evening) just me (Sep 22)
- Re: .ORG problems this evening Todd Vierling (Sep 18)
- Re: .ORG problems this evening Keptin Komrade Dr. BobWrench III esq. (Sep 18)
- Re: .ORG problems this evening E.B. Dreger (Sep 18)
- Re: .ORG problems this evening Todd Vierling (Sep 18)