Using singleinstancestore on a large scale (thousands of recipients)

[+archive.info-cyrus at utdallas.edu]

On Tue, 13 Jan 2004, Sebastian Hagedorn wrote:

> we've got Cyrus 2.1.16 running on Red Hat AS 2.1 with singleinstancestore
> and it's working well. A common case is that mails will have up to 5
> recipients:
>
> -rw-------    5 cyrus    mail         3754 Jan 13 11:13
> /var/spool/imap/S/user/a0620/88222.
>
> We haven't yet moved all our student accounts to Cyrus, but once we've done
> that, I'd like to be able to use this mechanism for sending mails to all of
> them. We've got around 30,000 student accounts. Now I wonder:
>
> - can a single inode have 30,000+ links? We're using ext3 as this is the
> only file system supported by Red Hat.
>
> - can I invoke "deliver" with such a long argument list? If not, is there
> an alternative?

We don't have as many students, but we see a fair number of "large
distribution" posts as well.  You don't indicate what MTA you're
using, but as pointed out, you need to use LMTP for this feature to
have any impact.

If you're using Postfix, you can control how many recipients are
allowed to be handled by a single post:

# Cyrus will hard link messages to multiple recipients
# on the same Cyrus partition.
lmtp_destination_recipient_limit = 3000

So a message to 6K will result in two messages with 3K links to each.
I figured that was good enough, and not likely to freak anything out.

-- 
Amos