[Gluster-users] Question on the rename atomicity behavior in gluster

[Rama Shenai]

Hi, We had some questions with respect to expectations of atomicity of
rename in gluster.

To elaborate :

We have setup with two machines (lets call them M1 and M2) which
essentially access a file (F) on a gluster volume (mounted by M1 and M2)
A program does the following steps sequentially on each of the two machines
(M1 & M2) in an infinite loop
 1) Opens the file F in O_RDWR|O_EXCL mode, reads some data and closes (F)
 2)  Renames some other file F' => F

Periodically either M1 or M2 sees a "Stalefile handle error" when it tries
to read the file (step (1)) after opening the file in O_RDWR|O_EXCL (the
open is successful)

The specific error reported the client volume logs
 (/var/log/glusterfs/mnt-repos-volume1.log)
[2016-03-21 16:53:17.897902] I [dht-rename.c:1344:dht_rename]
0-volume1-dht: renaming master.lock
(hash=volume1-replicate-0/cache=volume1-replicate-0) => master
(hash=volume1-replicate-0/cache=<nul>)
[2016-03-21 16:53:18.735090] W [client-rpc-fops.c:504:client3_3_stat_cbk]
0-volume1-client-0: remote operation failed: Stale file handle

We see no error when: have two processes of the above program running on
the same machine (say on M1) accessing the file F on the gluster volume,
for which we want to understand the expectations of atomicity in gluster
specifically specifically for rename, and if the above is a bug.

Also  glusterfs --version => glusterfs 3.6.9 built on Mar  2 2016 18:21:14

We also would like to know if there any parameter in the one translators
 that we can tweak to prevent this problem

Any help or insights here is appreciated

Thanks
Rama
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