[OpenAFS-devel] Retry transaction creates on transient problems

[Derrick Brashear]

On Tue, Apr 28, 2009 at 3:04 AM, Rainer Toebbicke <rtb@pclella.cern.ch> wro=
te:
> Tom Keiser schrieb:
>
>>
>> Raising thread count is not a solution. =A0More to the point, this patch
>> introduces a trivially-exploitable (by rxnull conns, no less) thread
>> DoS against the volume server, and that's just not acceptable.
>>
>> The solution to this problem needs to happen client-side, period.
>>
>
>
> Tom,
>
> as you are aware the file server is trivially DoSsable. Even logical and
> valid requests from a batch farm of a few thousand clients like ours will
> lock it up in no time, which we solved here in a way that's perhaps even
> more contentious. A volserver DoS would rarely have a comparable impact, =
and
> 7005 can probably be firewalled out from the wild world without much loss=
.
>
> I agree however that introducing a DoS point even if it's only the 20th o=
r
> 30th on the list is a filthy habit of the past century. I'll check if tha=
t
> problem can be fixed on the client side without spaghettitizing the code
> significantly - when I get some time!

It can.
See the updated patch in 124635. Try if you can.


Derrick