[Mailman-Developers] Requirements for a new archiver
brad.knowles at skynet.be
Wed Oct 29 23:00:48 EST 2003
At 10:47 PM -0500 2003/10/29, Barry Warsaw wrote:
> I'm not sure if Andrew Koenig is on this list, but he described an
> algorithm he developed to quickly find messages in an mbox file. If
> he's here, maybe he can talk about it.
7th edition mbox files are a pain. There are other mailbox file
formats that are much better and easier to parse (UW-IMAP .mbx being
> I really don't like mbox files, primarily because they require munging
> From lines in the body of the message. MMDF would be better, but I
> think ideal from a philosophical point of view would be
> one-message-per-file if it can be done efficiently cross-platform.
Therein lies the problem. Some filesystems make this more
feasible than others, at least on larger scale systems.
> Maybe file system experts here can provide pointers or advice on exactly
> which file and operating systems make this approach feasible, even for
> huge message counts.
SGIs XFS on Irix does a pretty good job, with hashed directory
structures, and an extent-based journaling filesystem. Regretfully,
I don't think that all of these features are fully supported under
the Linux version of XFS, and that work has basically ground to a
halt with the lay-offs of all the key SGI people who had been working
on XFS. Veritas VxFS also does a good job in this area.
Other than SGI XFS for Irix and Veritas VxFS, I don't know of any
good solutions to this problem at the filesystem level.
Kirk McKusick and Eric Allman agree with you that this is a
proper filesystem problem that should be solved at the filesystem
level (at least, that's what they've said to me when I brought this
issue up to them), and they feel you should not attempt to solve
filesystem problems with "tricks" like INN timecaf/timehash cycbufs.
However, while that's nice in theory, that doesn't necessarily
help us here in the real world.
Brad Knowles, <brad.knowles at skynet.be>
"They that can give up essential liberty to obtain a little temporary
safety deserve neither liberty nor safety."
-Benjamin Franklin, Historical Review of Pennsylvania.
GCS/IT d+(-) s:+(++)>: a C++(+++)$ UMBSHI++++$ P+>++ L+ !E-(---) W+++(--) N+
!w--- O- M++ V PS++(+++) PE- Y+(++) PGP>+++ t+(+++) 5++(+++) X++(+++) R+(+++)
tv+(+++) b+(++++) DI+(++++) D+(++) G+(++++) e++>++++ h--- r---(+++)* z(+++)
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