Re: synchronizing gnus sessions on multiple computers

[Eric Abrahamsen]

"Roland Winkler" <winkler@gnu.org> writes:

> On Fri, Sep 10 2021, Bob Newell wrote:
>> I have rsync'd gnus for years with success. In addition to the files
>> already listed I sync .newsrc.eld, but that is updated infrequently.
>> Not strictly gnus entries, but related closely enough, I also sync
>> .authinfo and .msmtprc (as I use msmtp) and also .bbdb.
>
> Thanks to everyone who replied to this thread.
>
> When you are rsyncing gnus, are you doing this while emacs is running on
> the different machines?  Or are you starting a fresh emacs session after
> all the files got updated on a machine?
>
> Digging through things I realized that .newsrc.eld seems to store
> article marks.  For example it sets gnus-newsrc-alist that holds an
> assoc list of read articles.  However, in a running emacs session the
> same information is stored also in gnus-newsrc-hashtb.  So the question
> becomes: What steps are needed to fully restart gnus while emacs is
> running so that internal variables such as gnus-newsrc-hashtb get
> re-initialized, too.
>
> -- I realized that testing all this does not require two different
> machines.  But two instances of emacs running on one computer
> effectively give the same situation to play with.  It seems that a
> running gnus session does not warn the user that another emacs instance
> has fiddled with files such as .newsrc.eld.  Is this true?

Yes, the .newsrc.eld file only gets written when you save Gnus ("s" in
the *Group* buffer), and I would absolutely not try to update files for
a Gnus that's still running, it will not handle that gracefully. It
should, however, be enough to shut Gnus down first (you can see the
`gnus-clear-system' function to see what happens then), rsync, then
restart Gnus.