245258 - Thunderbird does not allow zero connection cache

Status: RESOLVED WORKSFORME

(Thunderbird :: General, defect)

Description

[Russ Fink]

User-Agent:       Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.5) Gecko/20030917
Build Identifier: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.5) Gecko/20030917

I'm running T-bird 0.6 using IMAP/TLS to connect to the mail server.  It is
running behind a firewall that terminates SSL sessions that are idle for more
than one minute (I know, have no control over it).  I have set refresh checking
to 1 minute, but get periodic connection terminated messages if the firewall
kills the connection faster than Thunderbird can check it.  

One workaround would be to disable connection caching, but alas, Thunderbird
does not allow 0 connection caches.  See reproduce for exact steps.

Reproducible: Always
Steps to Reproduce:
1. Start Thunderbird 0.6.  Go to Tools, Account Settings, Server Settings,
Advanced, verify "5" as the current (default) maximum number of server
connections to cache.
2. Change "5" to "0", click "OK", then "OK" on the Server Settings dialog, then
File, Quit to exit Thunderbird.
3. Restart Thunderbird, reopen Server Settings, Advanced dialog and verify that
max server connections is reset to "5".
4. Change "5" to "1", "OK" the dialogs, quit Thunderbird.  
5. Restart Thunderbird, verify max server connections is correctly remembered as
"1".
6. Alternatively, quit Thunderbird, hand-edit "prefs.js", change
mail.server.server1.max_cached_connections value to 0, start and quit
Thunderbird, relook at "prefs.js" - the value is reset to "5".

Actual Results:  
Can set server cached connections to any positive integer strictly greater than
zero.

Expected Results:  
Allowed value of zero, meaning do not cache connections.

Comment 1

[Mark Murawski]

this bug also exists in 0.7.1 (20040626)

Comment 2

[Paul Bowsher]

(In reply to comment #1)
> this bug also exists in 0.7.1 (20040626)
> 

Confirmed also in 0.7.3 using same steps

Comment 3

[Jo Hermans]

*** Bug 306374 has been marked as a duplicate of this bug. ***

Comment 4

[Jo Hermans]

*** Bug 275624 has been marked as a duplicate of this bug. ***

Comment 5

[Bill C. Riemers]

*** Bug 306374 has been marked as a duplicate of this bug. ***

Comment 6

[Bill C. Riemers]

This bug effects  all platforms.  I have verified it on Windows, Linux, and MacOSX.
Please change the Hardware and OS settings for this bug.

Also, since it seems to a show stopper on any imap server that blocks multiple
connections, please change the severity to critical.

Comment 7

[Gary Kwong [:gkw] [:nth10sd] (NOT official MoCo now)]

Reporter, does the issue still occur with the latest supported 2.0.0.x / Shredder trunk nightlies?

(1.5.0.x is now end-of-life and the latest supported Thunderbird version 2 is 2.0.0.16)

Comment 8

[Gary Kwong [:gkw] [:nth10sd] (NOT official MoCo now)]

Email from reporter:


This ticket was reported about 3 years ago.  I no longer am employed in, or are using that environment so I have no way of verifying the original problem.

As I seem to recall, I was behind an insanely paranoid firewall that automatically terminated dormant SSL connections every minute without sending resets to the client.  Because 1 minute was less than the tcp keepalive, and if I were not constantly browsing the IMAP structure and causing requests to reset the firewall's connection timer, Thunderbird would not know the connection was terminated and it assumed wrongly that the connection was always there and active when it needed it.  When it would try checking the IMAP folder later on, it would cause a hang.

Again, all from memory, so my memory might be wrong.

The solution I was trying for was setting connection cache to zero, so that Thunderbird would renegotiate a fresh connection each time it wanted to do something - check IMAP updates, send mail, and so on.  Based on the user interface, it would not accept a setting of "zero" in neither the connection cache field nor the configuration file.  That led to the problem and bug report.

If you want to test this, you might try setting the connection cache to one, use an SSL connection to an IMAP account, and then send the *server* a RST packet only one minute into the problem, then try to navigate to an IMAP directory in Thunderbird.  It should produce the problem.  Next, set connection cache to zero, and do the same test, and it should work because Thunderbird should renegotiate the connection.

Sorry I don't have any more information.  I understand about the three years ~ nobody gets paid to do open source, so it's just an unfortunate lag.

Comment 9

[Gary Kwong [:gkw] [:nth10sd] (NOT official MoCo now)]

Mark, Paul, Bill, does this bug affect any of you too?

Comment 10

[Bill C. Riemers]

It doesn't effect me anymore.   "freeshell.org" raised the maximum allowed connections to 10 in 2006.   None of the other imap servers I connected to had this type of restriction.

Bill

Comment 11

[Joshua Cranmer [:jcranmer]]

RESO WFM per comment 10.