Re: [Dovecot] v1.1 max connections per user
On Sat, June 30, 2007 7:50 pm, Charles Marcus said:
Timo Sirainen, on 6/30/2007 7:25 PM, said the following:
On Sat, 2007-06-30 at 19:11 -0400, Charles Marcus wrote:
Timo Sirainen, on 6/30/2007 6:43 PM, said the following:
v1.1 has now:
# Maximum number of connections allowed for a user. The limits are enforced # separately for IMAP and POP3 connections, so you can move this setting # inside protocol {} to have separate settings for them. NOTE: The user names # are compared case-sensitively, so make sure your userdb returns usernames # always using the same casing so users can't bypass this limit! #mail_max_user_connections = 10
Is 10 a good default? I'm assuming this is per IP?
No. I'm not sure if it should. Perhaps. It's mostly intended to prevent unintentional abuse by stupid clients, so having 3+ thunderbirds open in different locations with each having 5 connections should probably be allowed.
Ok - you said 10 was the default - but then said that 15 (3 TBirds x 5) connections should be allowed, which is more than 10... so... you just meant that one could accommodate that by upping this limit to 15?
I like 15. That way it is high and isn't as likely to affect existing installations unless they manually set it to something lower. Or if you want to have a separate default for POP vs IMAP, I'd use 5 for POP and 15 for IMAP.
At 8:21 PM -0400 6/30/07, Bill Boebel wrote:
On Sat, June 30, 2007 7:50 pm, Charles Marcus said:
Timo Sirainen, on 6/30/2007 7:25 PM, said the following:
On Sat, 2007-06-30 at 19:11 -0400, Charles Marcus wrote:
Timo Sirainen, on 6/30/2007 6:43 PM, said the following:
v1.1 has now:
# Maximum number of connections allowed for a user. The limits are enforced # separately for IMAP and POP3 connections, so you can move this setting # inside protocol {} to have separate settings for them. NOTE: The user names # are compared case-sensitively, so make sure your userdb returns usernames # always using the same casing so users can't bypass this limit! #mail_max_user_connections = 10
Is 10 a good default? I'm assuming this is per IP?
No. I'm not sure if it should. Perhaps. It's mostly intended to prevent unintentional abuse by stupid clients, so having 3+ thunderbirds open in different locations with each having 5 connections should probably be allowed.
Ok - you said 10 was the default - but then said that 15 (3 TBirds x 5) connections should be allowed, which is more than 10... so... you just meant that one could accommodate that by upping this limit to 15?
I like 15. That way it is high and isn't as likely to affect existing installations unless they manually set it to something lower. Or if you want to have a separate default for POP vs IMAP, I'd use 5 for POP and 15 for IMAP.
Do concurrent sessions for POP3 really ever make sense?
-- Bill Cole bill@scconsult.com
On Sat, 30 Jun 2007 22:12:30 -0400 Bill Cole dovecot-20061108@billmail.scconsult.com wrote:
Do concurrent sessions for POP3 really ever make sense?
See http://wiki.dovecot.org/POP3Server "Session locking" for a rationale why dovecot defaults to allowing it. Another scenario would be a pop3 client at home downloading (leaving mail on the server) while the actual customer is looking at the mailbox with a pop3 webmail interface.
I suppose we would set mail_max_user_connections to 15 for IMAP (though having to support corporate mailboxes with a potentially large number of distinct clients might render this feature moot here and force us to set it to 30-50) and 2-3 for POP3. While at the same time I'll be praying that 1.5 million logins/day won't cause the tracking code for this to melt or leak memory. ;)
Regards,
Christian
Christian Balzer Network/Systems Engineer NOC chibi@gol.com Global OnLine Japan/Fusion Network Services http://www.gol.com/
participants (3)
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Bill Boebel
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Bill Cole
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Christian Balzer