On Fri, Oct 01, 2010 at 11:00:04AM -0700, Marc Eshel wrote: > On 10/1/2010 10:10 AM, J. Bruce Fields wrote: > >On Fri, Oct 01, 2010 at 08:40:36AM -0700, Marc Eshel wrote: > >> On 10/1/2010 5:33 AM, Benny Halevy wrote: > >>>On 2010-10-01 10:47, Boaz Harrosh wrote: > >>>>On 10/01/2010 08:12 AM, Tigran Mkrtchyan wrote: > >>>>> On 10/01/2010 06:17 AM, Marc Eshel wrote: > >>>>>>Hi Benny, > >>>>>> > >>>>>>Running connectathon I see that some times the clients decides to destroy > >>>>>>the session with the DS. The test continue and the session is > >>>>>>re-established. It looks like layout return reduces the hold on device > >>>>>>info the reduces the hold on the client struct which decide to destroy the > >>>>>>session. Is that a known problem? > >>>>>> > >>>>Yes, I want to emphasize on Marks words: "a known *problem*" > >>>Marc, assuming the code behaves as expected, does this cause any other badness > >>>like the GETATTRs you see going out to the DS? > >>> > >>>Benny > >>> > >>No i don't see any "badness" the test continues without errors and > >>this problem is not related to the GETATTRs I see on the DS but I > >>would consider destroying the session in short run of couple of > >>minutes some times more than one time as something bad. > >Why? > > > >I wouldn't expect session destruction/creation to be *that* expensive. > > I assumed that it is inexpensive. We are talking about potential > destruction/creation of session from every DS for each file IO if > there is no overlap in holding layouts, right ? Well, I guess the tradeoffs aren't obvious to me: if you end up having to set up an enormous number of sessions (and tcp connections, etc.) all at once, then I can see why it might be a problem. It would also seem inefficient to keep around an enormous number of those when they aren't being used for a while. --b. -- To unsubscribe from this list: send the line "unsubscribe linux-nfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
