#413 Multiple IMAP connections

[Amish]

I am using usermin-webmail for web access to mail account.

What I notice is that when I login to webmail, usermin makes 4 IMAP connections.

I would like to avoid this because when there are too many users accessing webmail, it loads the server unnecessarily.

So is there a config value which allows only 1 connection per webmail login?

Or is it just by design? If yes, is there anyway to improve this?

Thank you

[Jamie Cameron]

Do you mean it has 4 IMAP connections open at the same time, or it makes and closes 4 connections?

I would expect at most 2, one for each frame in the Usermin UI.

[Amish]

Here is maillog output:

It makes 4 connections and possibly disconnects. See the timestamp and pid, they all are connected and disconnected almost at same time.

Is there a workaround to this?

May 18 09:48:33 localhost dovecot: imap-login: Login: user=<myusername>, method=PLAIN, rip=127.0.0.1, lip=127.0.0.1, mpid=19253, secured
May 18 09:48:33 localhost dovecot: imap-login: Login: user=<myusername>, method=PLAIN, rip=127.0.0.1, lip=127.0.0.1, mpid=19256, secured
May 18 09:48:33 localhost dovecot: imap-login: Login: user=<myusername>, method=PLAIN, rip=127.0.0.1, lip=127.0.0.1, mpid=19258, secured
May 18 09:48:33 localhost dovecot: imap-login: Login: user=<myusername>, method=PLAIN, rip=127.0.0.1, lip=127.0.0.1, mpid=19260, secured
May 18 09:48:33 localhost dovecot: imap(myusername): Connection closed bytes=89/747
May 18 09:48:33 localhost dovecot: imap(myusername): Connection closed bytes=91/747
May 18 09:48:33 localhost dovecot: imap(myusername): Connection closed bytes=90/750
May 18 09:48:33 localhost dovecot: imap(myusername): Connection closed bytes=447/14607
May 18 09:48:33 localhost dovecot: imap-login: Login: user=<myusername>, method=PLAIN, rip=127.0.0.1, lip=127.0.0.1, mpid=19266, secured
May 18 09:48:34 localhost dovecot: imap-login: Login: user=<myusername>, method=PLAIN, rip=127.0.0.1, lip=127.0.0.1, mpid=19268, secured
May 18 09:48:34 localhost dovecot: imap-login: Login: user=<myusername>, method=PLAIN, rip=127.0.0.1, lip=127.0.0.1, mpid=19272, secured
May 18 09:48:34 localhost dovecot: imap-login: Login: user=<myusername>, method=PLAIN, rip=127.0.0.1, lip=127.0.0.1, mpid=19274, secured
May 18 09:48:34 localhost dovecot: imap(myusername): Connection closed bytes=73/717
May 18 09:48:34 localhost dovecot: imap(myusername): Connection closed bytes=116/2921
May 18 09:48:34 localhost dovecot: imap(myusername): Connection closed bytes=74/720
May 18 09:48:34 localhost dovecot: imap(myusername): Connection closed bytes=74/715
May 18 09:48:43 localhost dovecot: imap-login: Login: user=<myusername>, method=PLAIN, rip=127.0.0.1, lip=127.0.0.1, mpid=19308, secured
May 18 09:48:44 localhost dovecot: imap(myusername): Connection closed bytes=166/6737
May 18 09:48:46 localhost dovecot: imap-login: Login: user=<myusername>, method=PLAIN, rip=127.0.0.1, lip=127.0.0.1, mpid=19312, secured
May 18 09:48:46 localhost dovecot: imap(myusername): Connection closed bytes=419/21805
May 18 09:48:46 localhost dovecot: imap-login: Login: user=<myusername>, method=PLAIN, rip=127.0.0.1, lip=127.0.0.1, mpid=19315, secured
May 18 09:48:47 localhost dovecot: imap-login: Login: user=<myusername>, method=PLAIN, rip=127.0.0.1, lip=127.0.0.1, mpid=19317, secured
May 18 09:48:47 localhost dovecot: imap-login: Login: user=<myusername>, method=PLAIN, rip=127.0.0.1, lip=127.0.0.1, mpid=19319, secured
May 18 09:48:47 localhost dovecot: imap-login: Login: user=<myusername>, method=PLAIN, rip=127.0.0.1, lip=127.0.0.1, mpid=19321, secured
May 18 09:48:49 localhost dovecot: imap(myusername): Connection closed bytes=219/1647
May 18 09:48:49 localhost dovecot: imap(myusername): Connection closed bytes=222/1656
May 18 09:48:49 localhost dovecot: imap(myusername): Connection closed bytes=225/1647
May 18 09:48:49 localhost dovecot: imap(myusername): Connection closed bytes=286/781353
May 18 09:50:58 localhost dovecot: imap-login: Login: user=<myusername>, method=PLAIN, rip=127.0.0.1, lip=127.0.0.1, mpid=19981, secured
May 18 09:50:58 localhost dovecot: imap-login: Login: user=<myusername>, method=PLAIN, rip=127.0.0.1, lip=127.0.0.1, mpid=19984, secured
May 18 09:50:59 localhost dovecot: imap-login: Login: user=<myusername>, method=PLAIN, rip=127.0.0.1, lip=127.0.0.1, mpid=19987, secured
May 18 09:50:59 localhost dovecot: imap-login: Login: user=<myusername>, method=PLAIN, rip=127.0.0.1, lip=127.0.0.1, mpid=19989, secured
May 18 09:51:01 localhost dovecot: imap(myusername): Connection closed bytes=219/1647
May 18 09:51:01 localhost dovecot: imap(myusername): Connection closed bytes=222/1656
May 18 09:51:01 localhost dovecot: imap(myusername): Connection closed bytes=225/1647
May 18 09:51:01 localhost dovecot: imap(myusername): Connection closed bytes=298/781541

[Jamie Cameron]

I had a look into Usermin's IMAP code, and found that it does make un-necessary IMAP connections if you have multiple folders. This will be fixed in the next release .. or you can apply the code fix from https://github.com/webmin/webmin/commit/43f73bfd019b5ee885cb41870c4fbb4697a9f01a to /usr/{share,libexec}/usermin/mailbox/folders-lib.pl

[Amish]

Thanks for quick fix.

Since I am using live server, I just want to be sure that this fix does not pose any risk.

i.e. its a simple fix which does not really require thorough testing.

So is the patch really that safe to apply directly?

I will put blind trust on ur words. And in anycase you will not be responsible :). I just need a go ahead nod.

Thanks.

[Jamie Cameron]

Yes, it is safe to apply. But keep a backup copy of the modified file, just in case..

[Amish]

Thanks for the answer. Does the same fix apply to webmin as well?

Because I see files are identical.

Thank you

[Jamie Cameron]

Yes .. although webmin doesn't normally make IMAP connections.

[Amish]

Thanks again. As always, u r really fast at fixing things and even replying assertively.