Fwd: Re: [OpenAFS] Salvager runs constantly

[Derrick J Brashear]

On Thu, 6 Jun 2002, Steve Devine wrote:

> All,
> 
> I received this from Todd and Derrick and they are right I was able to put 
> everything in except the -dontdelay arg.

I replied to Steve privately, but basically we fixed this problem another
way last year during the Arla/AFS hackathon. Most legitimate errors are
not throttled in the OpenAFS fileserver without need for extra switches.



> ----------  Forwarded Message  ----------
> Subject: Re: [OpenAFS] Salvager runs constantly
> Date: Thu,  6 Jun 2002 15:31:38 -0400 (EDT)
> From: Todd_DeSantis@transarc.com
> To: sdevine@msu.edu
> Cc: shadow@dementia.org
> 
> 
> Hi -
> 
> OpenAFS probably does not know about the
> 
> 	-dontdelay
> 
> switch which stops some RX behavior to NOT delay return packets to a
> client because of some constant error return.
> 
> One of RXs ways of preventing a client from killing a fileserver with
> requests is that if it sees a client making a request which will
> return an error - if that error happens 10 times in a row, then the
> fileserver will delay sending back the response for 3 seconds.  So
> this stops a constant attack from some rogue client.
> 
> Unfortunately, NT clients using EXPLORER try to stat all directories
> and if the directory is NOT accessible by this user because of ACLs,
> the fileserver sees these "Permission errors" as a constant error and
> then delays the response to the cleint and the NT client performance
> can suffer.
> 
> SO the -dontdelay does not place this 3 second delay into the error
> return.