Re: [Gluster-devel] GlusterFS hangs/fails: Transport endpoint is not connected

[Fred Hucht]

Hello Harald!

I didn't test Infiniband transport until now, as I don't want to  
interfere with the parallel applications which are running over  
Infiniband. Gigabit Ethernet throughput would be sufficient for us at  
the moment.

Today "only" three nodes were affected, yesterday it were nine nodes.  
The problems only occur on nodes to which jobs are scheduled which  
use /scratch as working directory: We test the filesystem in normal  
operation, one user submits jobs to the queueing system which use / 
scratch/... as working directory. While some of his jobs run without  
problems, other jobs fail due to FS problems. No problems occur over  
the usual NFS home directory.

When I test the FS with, e.g., dd on all nodes in parallel, no  
problems occur.

Which timeout shall I increase?

Regards,

     Fred

On 25.11.2008, at 13:18, Harald Stürzebecher wrote:

> Hello!
>
> <Disclaimer>
> I'm just a small scale user with only a few month experience with
> GlusterFS so my conclusions might be totally wrong.
> </Disclaimer>
>
> 2008/11/25 Fred Hucht <address@hidden>:
> > Hi devels!
> >
> > We consider GlusterFS as parallel file server (8 server nodes) for  
> > our
> > parallel Opteron cluster (88 nodes, ~500 cores), as well as for a  
> > unified
> > nufa /scratch distributed over all nodes. We use the cluster within a
> > scientific environment (theoretical physics) and use Scientific  
> > Linux with
> > kernel 2.6.25.16. After similar problems with 1.3.x we installed  
> > 1.4.0qa61
> > and set up a /scratch for testing using the following script
> > "glusterconf.sh" which runs local on all nodes on startup and  
> > writes the two
> > config files /usr/local/etc/glusterfs-{server,client}.vol:
>
> [...]
>
> > The cluster uses MPI over Infiniband, while GlusterFS runs over TCP/ 
> > IP
> > Gigabit Ethernet. I use FUSE 2.7.4 with patch fuse-2.7.3glfs10.diff  
> > (Is that
> > OK? The patch succeeded)
>
> Interesting setup, not using Infiniband for GlusterFS. The GlusterFS
> homepage says "GlusterFS can sustain 1 GB/s per storage brick over
> Infiniband RDMA". Personally I'd like to know if you did try it at
> some time and chose not to use it?
>
> > Everything is fine until some nodes which are used by a job block  
> > on access
> > to /scratch or, sometimes later, give
> >
> > df: `/scratch': Transport endpoint is not connected
> >
> > The glusterfs.log on node36 is flooded by
>
> [...]
>
> > On node68 I find
>
> [...]
>
> > The third affected node node77 says:
>
> [...]
>
> > As I said, similar problems occurred with version 1.3.x. If these  
> > problems
> > cannot be solved, we have to use a different file system, so any  
> > help is
> > very appreciated.
>
> If I read that correctly, there are only three nodes out of 88
> affected by this problem. In that case I think I'd look for hardware
> problems first. Do you have an easy way to check your network
> connections for e.g. packet loss.
> Increasing timeouts might help until the real problem can be found  
> and fixed.
> Additionally, I'd like to suggest running a test using Infiniband - if
> possible - to rule out any Ethernet-related problems.
>
>
> Harald Stürzebecher
>
>
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Dr. Fred Hucht <address@hidden>
Institute for Theoretical Physics
University of Duisburg-Essen, 47048 Duisburg, Germany