Why forwarding is a Bad Thing

[Brad Knowles]

At 7:27 PM +0000 3/22/01, Jim Reid wrote:

>             You're always going to get deferred lookups because mail
>  will get delivered to domains that have badly broken or dead name
>  servers anyway. I would have thought that the way to deal with that is
>  engineer the mail system to chuck mail for delivery to tardy servers
>  on to a system set up for that? ie If it can't get an answer from the
>  DNS and open a connection to port 25 in N seconds, throw the mail at
>  an overflow system that is set up to cope with a deep queue of mail
>  bound for "slow" servers. "If I can't deliver this mail *right now*,
>  get rid of it to somebody else so my fast queue doesn't back up."

	I'm sure that we would have gotten to this point at some time in 
the future, however at the time I was talking to Eric Allman and 
Bryan Beecher, this sort of solution was not being typically 
implemented and suggested for sites with large volumes of traffic, 
although they had discovered that using Paul Pomes' re-mqueue script 
did not make any sense as it caused as many synchronous meta-data 
updates by moving files around itself as it solved by making the 
various queues smaller.

	This must have been a typical solution that they discovered at 
some time after I left AOL.

--
Brad Knowles, <brad.knowles at skynet.be>

/*     efdtt.c     Author:  Charles M. Hannum <root at ihack.net>             */
/*                                                                         */
/*     Thanks to Phil Carmody <fatphil at asdf.org> for additional tweaks.    */
/*                                                                         */
/*     Length:  434 bytes (excluding unnecessary newlines)                 */
/*                                                                         */
/*     Usage is:  cat title-key scrambled.vob | efdtt >clear.vob           */
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#define m(i)(x[i]^s[i+84])<<
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;c=c>y)c+=y=i^i/8^i>>4^i>>12,i=i>>8^y<<17,a^=a>>14,y=a^a*8^a<<6,a=a>>8^y<<9,k=s
[j],k="7Wo~'G_\216"[k&7]+2^"cr3sfw6v;*k+>/n."[k>>4]*2^k*257/8,s[j]=k^(k&k*2&34)
*6^c+~y;}}