Future Ideas wiki page

[Wil Cooley]

Bron Gondwana wrote:

> Anyway, I'd love feedback on any or all of it, and if there
> are other things that you feel are really important for the
> future viability of Cyrus I'd love to hear about them as well.
> I haven't yet had a chance to look at the QRESYNC stuff that
> Ken's already done for 2.4, and we might wind up releasing
> a 2.4 without a lot of these changes just because there's a
> lot of work in there!

Thanks for asking! I'll just mention a few of mine here and if you like them or
see them as useful, I will add them to the wiki. I think I kinda got carried
away when I started trying to remember things I've wished for; sorry this is so
long.

1. It would be nice from a provisioning standpoint to be able to enumerate
available partitions and their capacities within the IMAP protocol itself. This
way, provisioning scripts could decide intelligently which backend and partition
to use without resorting to SNMP or SSH or other. Is this something that could
be delivered in an annotation or "ID" response perhaps?

2. Being able to run "(cyr)quota -f" on individual partitions easily would be
nice. 'squatter' too. There may be other maintenance utilities that could
benefit from being easily isolated to a particular partition, like the
consistency checker in item #4 on your list.

How about setting a server shutdown or motd message that applies only to a
particular partition? We've had cases where we had to restore a whole partition
after some SAN buggery. It would have been nice if we could have locked out or
at least provided a message directly to the affected users.

3. Another idea related to partitioning: Would there be any value in
partitioning the user config data parallel to the mailbox spools? By that I mean
that a user foo's mailbox in /var/spool/imap/01/**/foo has sub/seen data in
/var/lib/imap/user/01/**/foo.{seen,sub} and likewise for the sieve data. With
this, you could move/restore/recover partitions on different hosts. I can think
of a few cases where that would make sense, but maybe they're unlikely cases.

Somewhat orthogonally, what about being able to configure separate
metapartitions per metadata type for a partition? For example, as you mention on
#5 on your list, one metapartition to put the cyrus.index files on a fast SSD
and another to put the large squatter files on cheaper, slower storage?

4. If you're going to be computing SHA1s for messages anyway, would there be any
value in hashing the message files across sub-directories, so that directories
wouldn't get to be so large? Are there cases where imapd would do a directory
listing or is all of that done through the index and cache files? Otherwise, I
guess only local admins and backup software would benefit. And anyway, would it
be faster to open and list 1,000 files in 23 directories than to open one
directory and list 23,000 files? Would that be overshadowed by the cost of
opening all 23,000 files (which I presume it would need to if it were resorting
to listing them).

5. What about toggling whatever CYRUS_VERBOSE enables by sending a signal or
something like that? On my test systems I have gotten some good info from that
which I would not have otherwise gotten but it is not feasible to enable it on
my production systems.

6. sieveshell: Command to report supported extensions (a little more intuitive
than 'nc localhost sieve').

7. Doc additions: (I could do some of these, if I'd make the time...) There are
some cyradm commands that, in a Murder setup, need to be run from a front-end or
back-end (sometimes a particular back-end). For example, it took me a while to
figure out that 'xfer' needs to be run from the source back-end and not from a
front-end. (Maybe that is a feature request itself?) For some of the maintenance
utilities that check and modify the spools or config data, it's not always clear
if they can be run with the server live or if it should be shut down, such as
'ctl_cyrusdb -r' or 'quota -f'.

8. Last one, I promise: lmtpproxyd to use local mupdate instead of having to hit
the master. Maybe this has changed? I don't see it mentioned in the change log.

Wil

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