nnimap, marks and agent leftovers

nnimap, marks and agent leftovers

[Bjørn Mork]

hello,

just had a bad experience wrt subject, and though I might share a bit of
advice so others don't do the same as me.  

I have learned that nnimap and agent don't mix.  It makes all sorts of
weird things happening, and sometimes hides mail to the degree that I
haven't yet found a way to display it using Gnus with agent.

So I don't use agent for my nnimap servers anymore.

But today I managed to press 'L' (offline) in the server buffer when I
meant to press 'C' (close) to temporarily close the connections for a
while (because I knew the servers would be inaccessible).  When opening
the connections again, I noticed a large number of new mails in all
groups and immediately thought that all my marks had disappeared.  But
that was not what happend.  The marks had been reset to the last time I
used agent on these servers!  Looks like Gnus found the ancient data
under ~/News/agent/nnimap/ and used it, even though the servers were not
agentized (they are not listed in ~/News/agent/lib/servers).

So my advice is:  Don't just disabe agent on nnimap servers, but be sure
to delete/move all data from ~/News/agent/nnimap/ as well!

I guess Gnus should do this when de-agentizing a server. But I really
think the whole issue just demonstrates the agent design problem: Even
if the servers *were* agentized, Gnus should not have overwritten newer
flags on the servers with the outdated local version.  There are plenty
of possibilities for the local flags to end up being older than the
server flags.


Bjørn

Re: nnimap, marks and agent leftovers

[Bjørn Mork]

Bjørn Mork <bjorn@mork.no> writes:

>  When opening
> the connections again, I noticed a large number of new mails in all
> groups and immediately thought that all my marks had disappeared.  But
> that was not what happend.  The marks had been reset to the last time I
> used agent on these servers!  Looks like Gnus found the ancient data
> under ~/News/agent/nnimap/ and used it, even though the servers were not
> agentized (they are not listed in ~/News/agent/lib/servers).

Sorry, as usual I jumped too quickly to a conclusion.  Looks like
whatever flags Gnus were using never were pushed to the servers.

Reopening the connections just weren't enough for Gnus to refresh its
local copy.  But after restarting Gnus, everything were back to normal.
Pfew! 



Bjørn

Re: nnimap, marks and agent leftovers

[Steinar Bang]

>>>>> Bjørn Mork <bjorn@mork.no>:

> I have learned that nnimap and agent don't mix.  It makes all sorts of
> weird things happening, and sometimes hides mail to the degree that I
> haven't yet found a way to display it using Gnus with agent.

What happens, are:
 - Sometimes the wrong article is cached
 - Sometimes a piece of NOV data is cached instead of the article 

Unfortunately I haven't been able to reproduce _when_ this happens.

I've tried debugging the agent caching in nnimap with the new nnimap
backend (the attempts are somewhere in this group).

> So I don't use agent for my nnimap servers anymore.

Note: all of these issues appeared when agent met the new nnimap backend
(which I love for its speed)

I think maybe the agent should be a candidate for a full rewrite....?

Not something I can step up to volunteer for myself, unfortunately.

[snip!]
> used agent on these servers!  Looks like Gnus found the ancient data
> under ~/News/agent/nnimap/ and used it, even though the servers were
> not agentized (they are not listed in ~/News/agent/lib/servers).

This has always been the case, I think. Not something that appeared with
the new nnimap backend.

> So my advice is:  Don't just disabe agent on nnimap servers, but be sure
> to delete/move all data from ~/News/agent/nnimap/ as well!

Quite possibly.

Note that when the agent caches the wrong stuff, deleting the wrongly
cached article under ~/News/agent/nnimap/ is enough to fix the issue
with strange behaviour.

Having to do so at all, is kind of annoying, though...