On Tue, Jan 31, 2023 at 2:55 PM Andrew J. Romero <romero@xxxxxxxx> wrote: > > > > > What you are describing sounds like a bug in a system (be it client or > > server). There is state that the client thought it closed but the > > server still keeping that state. > > Hi Olga > > Based on my simple test script experiment, > Here's a summary of what I believe is happening > > 1. An interactive user starts a process that opens a file or multiple files > > 2. A disruption, that prevents > NFS-client <-> NFS-server communication, > occurs while the file is open. This could be due to > having the file open a long time or due to opening the file > too close to the time of disruption. > > ( I believe the most common "disruption" is > credential expiration ) > > 3) The user's process terminates before the disruption > is cleared. ( or stated another way , the disruption is not cleared until after the user > process terminates ) > > At the time the user process terminates, the process > can not tell the server to close the server-side file state. > > After the process terminates, nothing will ever tell the server > to close the files. The now zombie open files will continue to > consume server-side resources. > > In environments with many users, the problem is significant > > My reasons for posting: > > - Are not to have your team help troubleshoot my specific issue > ( that would be quite rude ) > > they are: > > - Determine If my NAS vendor might be accidentally > not doing something they should be. > ( I now don't really think this is the case. ) It's hard to say who's at fault here without having some more info like tracepoints or network traces. > - Determine if this is a known behavior common to all NFS implementations > ( Linux, ....etc ) and if so have your team determine if this is a problem that should be addressed > in the spec and the implementations. What you describe --- having different views of state on the client and server -- is not a known common behaviour. I have tried it on my Kerberos setup. Gotten a 5min ticket. As a user opened a file in a process that went to sleep. My user credentials have expired (after 5mins). I verified that by doing an "ls" on a mounted filesystem which resulted in permission denied error. Then I killed the application that had an opened file. This resulted in a NFS CLOSE being sent to the server using the machine's gss context (which is a default behaviour of the linux client regardless of whether or not user's credentials are valid). Basically as far as I can tell, a linux client can handle cleaning up state when user's credentials have expired. > > > > Andy > > > > >
