[dovecot] observations/qestions of mbox concurrency ability (Yay!) on current CVS
Hi, all.
Just been testing out the latest "CVS" (in quotes because I'm rsyncing the source tree) versions of Dovecot lately.
Tested having Pine on the machine on which Dovecot was running, talking IMAP, as well as another Pine instance, this time from my Windows machine over the wire. Things seem to be working wonderfully. Deleted a message using one instance, then refreshed the list on the other. *poof* Gone.
Though I'm seeing periodic "IMAP protocol error" messages in Pine, but they don't seem to be affecting the software's operation that I can see.
Anything in particular I should be on the lookout for?
Otherwise, you just made my day. Correction; week. :D
--Ian.
On Sun, 2002-10-20 at 09:38, Ian R. Justman wrote:
Tested having Pine on the machine on which Dovecot was running, talking IMAP, as well as another Pine instance, this time from my Windows machine over the wire. Things seem to be working wonderfully. Deleted a message using one instance, then refreshed the list on the other. *poof* Gone.
Though I'm seeing periodic "IMAP protocol error" messages in Pine, but they don't seem to be affecting the software's operation that I can see.
Anything in particular I should be on the lookout for?
By default Dovecot uses .lock file and flock() locking. Some programs may use fcntl() which doesn't work with flock(), but most use .lock file as well so it doesn't really matter. I'm going to make the locking style configurable later.
Anyway, I don't know of any reasons for mailbox corruption, but we don't lock the mailbox when reading from it, so it is possible that someone else might modify (expunge) the mailbox while Dovecot is reading it and the IMAP client gets corrupted message.
I was thinking about fixing this using read-locking fcntl() / flock(). Maybe it could optionally create the .lock file as well, but that'd slow down simultaneous reads.
Oh, and the mbox parsing code could use better checking, if there's any bugs it will corrupt the mailbox at expunge/flag rewrite. I haven't seen those though for the month or two that I've been using Dovecot+mbox to read my mail.
participants (2)
-
Ian R. Justman
-
Timo Sirainen