[leafnode-list] Re: Two (or more) systems synchronization

[Martin <mailinglisten@xxxxxxxxxxxxxxxx>]

Hello,

Am 06.10.2007 schrieb Angel Martin Alganza:
> What I would like to do is somehow synchronize my notebook to my mail
> box so that I can read my newsgroups both online (at the leafnode box
> or at any other online box) and off-line (at my notebook without
> permanent internet connection.  Of course, I want that posts that I
> have already read in either of them don't show up in the other.

That's tricky.

Here's why:

First of all, each server gives article numbers. So when your leafnode
finds a new article, it increases the current article number for the
group, and gives it to the article. Your first task is: Keep the
article numbers synchronized. 

While using only two computers with one polling directly from the
other, this sounds easy. But it isn't: If the first computer finds an
article cancelled or superseded, before the second updates its news
spool, there's a difference in numbers. And it will be there forever
(or at least until the difference increases). If I remember correctly,
there's some solution with INN. I'm not sure, whether one wants to use
it. And I'm not sure, whether one wants to use INN just for this
purpose.

Second problem: Your news server does not know about read articles at
all. It just doesn't care. News server don't store data just for one
user. Their spool is intended to be read by everyone.

Your newsreader has its own idea of what articles are read. This file
typically looks like:
| gmane.leafnode.something:1-10,12,14-199
(That means, you read articles 1 to 10, 12 and 14 to 199. 11 and 13 are
unread.)

Not only do you have to keep your news spool synced, you also have to
copy/replace your newsrc (or whatever this file is called).


In short: In your current client/server-solution it's very difficult to
complete this task. Maybe some copying of the newsspool and the newsrc
would help. Be aware, that this may break things for your
leafnode-system. I don't know.

NNTP is not primarily thought for something like this.

> The ideal thing would be that my notebook news got synchronized with
> my main box, then I go off-line, I read and write my news and, when I
> connect my notebook again, it synchronizes again to my main box
> (sending the posts I've written on the notebook, receiving new posts
> and deleting the posts I've read from the main box ---so that they
> don't show up when I read new on it---).
> 
> Is there a way to do that or should I just install leafnode also on my
> notebook and look for a way to synchronize the boxes at the reader
> (tin) level?  What would you suggest me to do?

Well, this sounds for some IMAP-solution...

(I do not know any program that could do the task.)

Just an example, free thoughts: To your newsserver (leafnode, of course)
would be given the ability to access newsgroups via IMAP. E.g.
| IMAP/gmane/leafnode/something
| IMAP/gmane/leafnode/users
| IMAP/gmane/leafnode/developers

Then you could set up any (good) IMAP-client to sync with the server,
and with every sync, the attributes (such as "read" or "marked as
important") are given to the server. On the other hand, the server
would give such attributes to the client.

But this is a solution far from reality (NNTP-servers are not intended
to save per-user-data and normally do not server IMAP accounts) and far
from your wishes (no tin, no leafnode).

I'm sorry.

I hope at least some things are more understandable...

With all the best wishes...

Martin
-- 
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