[Dovecot] Indexing Performance Question (was tpop3d vs dovecot)

[Nate]

At 08:57 PM 2/1/2007, FiL wrote:
>Too bad. I was almost ready to start migrating my mbox-based setup 
>to Maildir...
>One of the most important reasons for that - to speed things up and 
>lower disk IO.
>So now I just converted one 3Gb mailbox (88K mails) to Maildir and 
>tried accessing it via pop3...
>
># telnet enders2 110
>Trying 127.0.0.1...
>Connected to localhost.localdomain (127.0.0.1).
>Escape character is '^]'.
>+OK Dovecot ready.
>user filonovd
>+OK
>pass XXXXXX
>+OK Logged in.
>list                              < here comes looong wait
>-ERR Disconnected for inactivity.
>Connection closed by foreign host.
>
>There is no index for that Maildir. But dovecot can't even make one 
>in the first place. It just times out.
>It's really scares me. That means, that for pop3 users Maildir is so 
>much slower, than mbox?
>
>Please, somebody tell me this is not true.

As of rc21 which fixes a major indexing issue (the start of this 
thread), this shouldn't be a concern for you anytime except the very 
first time a mailbox is indexed.  From there on out it would only 
take a few milliseconds to index the new files which arrive.  88k 
messages must mean it's years worth of email (or tons of spam).

To do the first index you could increase the idle timeouts in dovecot 
(have to do it in the src/pop3/client.c) file as it's not a config 
option that i'm aware of.  I just modified both the 
CLIENT_OUTPUT_TIMEOUT and CLIENT_IDLE_TIMEOUT to 60*60.

Another option would be to defrag that 88k mailspool by copying it 
somewhere else, then copying it back so the operation happens faster, 
although personally I'd just change the idle timeouts and grin and 
bear it the first time.  maildir has so many advantages over mbox I 
would highly suggest it!

- Nate