[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

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

Hello Martin,

Thank you very much for such a great amount of interesting information.

On Sat, Oct 06, 2007 at 10:26:13PM +0200, Martin wrote:

> 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.

Does that mean that for a given group article numbers never get used
again?  I mean, is there one and only one article number 1 even when
the first post gets erased?

If that's how I have understood, it's very good news for me, since
synchronization at the server level is easy, then.  I simply need to
rsync /var/spool/news/ from my main box to my laptop, right?  I then
need my laptop not to fetch news from a server or anything other than
run leafnode to serve news to my news reader (tin).  Am I mistaken?

> 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 article cancelled or superseded, before the second updates its news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

As long as I rsync main-box -> laptop I keep the numbers the same,
won't I?  Unless I haven't understood something properly (English is
not my mother tongue, you know).

> (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.

Well, I like leafnode so much, and I think it has all the functions I
need (at least at the moment) that I would prefer to stick with it, if

> 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.)

That's also very convenient for me (I think), since I simply need then
to synchronize ~/.newsrc.  I actually need to copy it from the last
box I've read news to the other one.  For example, if I read news at
my main box during the week, I do nothing on the laptop during those
days.  On Friday, I close tin and copy ~/.newsrc over to my laptop and
run tin on it.  Shouldn't I be getting exactly the same posts I would
get if I kept running tin on my main box?  On Monday, I copy ~/.newsrc
from the laptop over to my main box and run tin on it, and keep going
reading news where I left.  Again, am I missing something here?

> 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).

Both tasks are very easy, and very quick for the number of news-groups
I read (less than 200) being all of them just text groups and a few of
them with very low traffic, in addition of having a fast internet
connection while synchronizing before (and after) of going off-line.

> 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.

I don't see what (and how) something could break, since I only rsync
the news spool from my main box to the laptop (new posts get copied
and erased ones get deleted on the laptop).

The only thing I can think about is that news-groups won't be
downloaded by leafnode since it is not aware of somebody (me) reading
them while I'm off-line, on the laptop.

I've just also realize that I might have another problem: posting from
the laptop.  Perhaps I could set up a way of holding my posts on the
laptop until I connect it to the Internet and then get the posts sent
without any fetching, of course, other than the rsync(-hronization) of
the news spool from my main box.

> NNTP is not primarily thought for something like this.

I hope the fact that it is not thought for it doesn't prevent me from
doing it. :-)

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

I would really prefer to use some simple scripts, I think, rather than
using IMAP, if at all possible... Let see.

> 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.

That sound interesting, although it seems more complicated (and I
don't know whether leafnode+tin could do; I don't want to change from
tin, really).

> 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 see. :-)

> I'm sorry.

Don't be.  Your information is of very much help for me to understand
how leafnode and the ~/.newsrc work.  I see much more clearly now how
I should proceed to try and set up what I want, apart from getting
posts written on the laptop is off-line sent when got on-line.

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

Much more.  Many, many thanks!


Angel Martin Alganza               Tel +34 958 248 926
Departamento de Genetica           Fax +34 958 244 073
Universidad de Granada               mailto:ama@xxxxxx
C/ Fuentenueva s/n             http://www.ugr.es/~ama/
E-18071 Granada, Spain     JabberID alganza@xxxxxxxxxx
  PGP Public key: http://www.ugr.es/~ama/ama-pgp-key
  3EB2 967A 9404 6585 7086  8811 2CEC 2F81 9341 E591
() ASCII Ribbon Campaign - http://www.asciiribbon.org/
/\ Against all HTML e-mail and proprietary attachments
Please avoid sending me Word or PowerPoint attachments
leafnode-list mailing list