[Gluster-users] strange "permission denied" problem

[Alex Crow]

On 16/04/15 19:46, Nikolai Grigoriev wrote:
> Hi,
>
> I am new to gluster and would appreciate if someone could help me to 
> understand what may be wrong.
>
> We have a small filesystem (currently - just one brick) and on the 
> same client node I have two processes. One is writing files to a 
> specific glusterfs share and another one is periodically scanning that 
> directory and loading all the files from there. Files are small, 
> hundreds of bytes at most. There are not too many files written, maybe 
> one in a couple of seconds.
>
> Quite often (about 20% of the cases) the "consumer" process fails to 
> open the file written by the "producer". The producer does create a 
> temporary file first and then renames it to its final name. Both 
> processes are Java apps.
>
>

I'm seeing a lot of this kind of thing reported on the list lately.

It makes me worry that glusterfs may not be production-ready for 
critical data that requires updates to be visible at the same instant in 
time across multiple clients. Should not updates be atomic and 
consistent across all connected clients? Is there a limitation of the 
present architecture? Or is there something we need to set on the server 
side to enforce such consistency? The available docs certainly don't 
make such things plain.

For our current proposed workload this is not very important but for 
applications like email storage for IMAP and transactional applications 
it's essential.

Thanks.