[OpenAFS] Re: 1.6 clients: rx version pings

Stephan Wiesand stephan.wiesand@desy.de
Fri, 2 Dec 2011 19:01:58 +0100

On Dec 2, 2011, at 18:23 , Andrew Deason wrote:

> On Fri, 2 Dec 2011 17:52:14 +0100
> Stephan Wiesand <stephan.wiesand@desy.de> wrote:
>> we had seen this during EAKC already: 1.6 clients are supposed to =
>> file servers once a second, yet they do so at much higher rates. As
>> the number of 1.6 clients is increasing here, this has become a real
>> problem.
> If you're talking about the rx nat keepalive ping (they appear as "rx
> version reply" packets on the wire), it's only supposed to be once =
> 20 seconds. I believe there were issues before where that would be =
> for _every_ connection to the fileserver, but I thought it was =
> somewhere (possibly post-1.6.0?). I assume Derrick can answer that
> faster than I can find it.

Yes, I believe that's what I'm talking about, and I recall it's even =
supposed to be 1/20 Hz, and sorry for not being precise. This is what I =
see on a former fileserver:

18:37:32.916181 IP client.afs3-callback > server.afs3-fileserver:  rx =
version (29)
18:37:32.916214 IP client.afs3-callback > server.afs3-fileserver:  rx =
version (29)
18:37:32.916242 IP client.afs3-callback > server.afs3-fileserver:  rx =
version (29)
18:37:32.916289 IP client.afs3-callback > server.afs3-fileserver:  rx =
version (29)
18:37:32.916325 IP client.afs3-callback > server.afs3-fileserver:  rx =
version (29)

It rather seems like "every connection the client ever had"...

rxdebug on the client lists no connection to the server.

The total rate of those incoming packets is several kHz - from 21 =
(former) clients.

>> Is there any way to prevent the client from doing this? Any way to at
>> least make it forget an old fileserver? Or at least reset the rate to
>> the 1 Hz it should be? Can this be disabled altogether? Supposed I
>> find the place in the code where these pings happen and just remove
>> them, what would be the consequences?
> If they are the nat keepalive pings, they're just for keeping port
> mappings open for nats and stateful firewalls and such. There should =
> a way to turn them off, but I don't believe there is right now.

Thanks a lot. I'll try to find them in the source and get rid of them. =
Still hoping for a hint making this search more efficient, though.

Thanks again,

Stephan Wiesand
Platanenenallee 6
15738 Zeuthen, Germany