Server changing IP address

[Fredrik Roubert]

Hello!

It seems to me that the Coda client upon first connecting to a server
caches the server's IP address so that if the server later changes IP
address, the client won't do a new DNS lookup but continue trying to
connect to the old IP address. Is that so? If so, is there any way to
get a client to update the IP address of a server? (It is, of course,
possible to re-initialize the client, but that will loose the cache.)

Cheers // Fredrik Roubert

--
Teglbrennerveien 7b  |  [phone]
NO-7013 Trondheim    |  http://www.df.lth.se/~roubert/

[u+codalist-wk5r]

Hi Fredrik,

On Sun, Dec 07, 2008 at 01:25:17PM +0100, Fredrik Roubert wrote:
> It seems to me that the Coda client upon first connecting to a server
> caches the server's IP address so that if the server later changes IP
> address, the client won't do a new DNS lookup but continue trying to
> connect to the old IP address. Is that so? If so, is there any way to

That's right.

> get a client to update the IP address of a server? (It is, of course,
> possible to re-initialize the client, but that will loose the cache.)

Unfortunately to the best of my knowledge not any reliable way.
As for today you should reinit all your clients when
a server you are using changes its adress. This is going to improve
but the corresponding fix is a hard one and will take time.

At reinit you may want to keep a copy of the old cache contents
and supply it to venus via mklka.

If you are using the current Aetey's Coda client installer ("cocli",
http://www.aetey.se/index.php?Static&pg=CodaInstHowto ), it will
take care of this operation when you reinit with -i flag (but will
not if you use -I).

Regards,
Rune

[Fredrik Roubert]

On Sun 07 Dec 17:16 CET 2008, u+codalist-wk5r@... wrote:

> At reinit you may want to keep a copy of the old cache contents
> and supply it to venus via mklka.

Hm, mklka seems to be totally undocumented. Is that so? The only
documentation I can find at all is this:

http://www.coda.cs.cmu.edu/maillists/codalist/codalist-2003/5215.html

This makes me think that the following is the correct command sequence:

mv venus.cache venus.cache.old
mklka index.lka venus.cache.old
venus -init
cfs lka +$PWD/index.lka

Is that correct? This will lead to having two cache directories, one
venus.cache and one venus.cache.old. Should that be so? If so, when can
venus.cache.old be removed?

Cheers // Fredrik Roubert

--
Teglbrennerveien 7b  |  [phone]
NO-7013 Trondheim    |  http://www.df.lth.se/~roubert/

[u+codalist-wk5r]

Hi Fredrik,

On Sun, Dec 07, 2008 at 10:37:50PM +0100, Fredrik Roubert wrote:
> Hm, mklka seems to be totally undocumented. Is that so? The only
> documentation I can find at all is this:
>
> http://www.coda.cs.cmu.edu/maillists/codalist/codalist-2003/5215.html

Can not say for sure about documentation, but anyway you should not have
to run it explicitely, as long as the only use is for preserving the cache
at reinit. Just use cocli.

> This makes me think that the following is the correct command sequence:
>
> mv venus.cache venus.cache.old
> mklka index.lka venus.cache.old
> venus -init
> cfs lka +$PWD/index.lka

Yes, something like that, assuming that venus is not running.
(note that this command sequence will not be very efficient if you already
have got venus.cache.old and that the third time it will not work at all)

> Is that correct? This will lead to having two cache directories, one
> venus.cache and one venus.cache.old. Should that be so? If so, when can
> venus.cache.old be removed?

Well, when you like.

The earlier you remove the lookaside storage, the more
cache misses will be served from the servers instead.

As an example, cocli removes the old cache copy at the next reinit.

Regards,
Rune