[Gluster-users] NFS service dying

Fri Jan 13 17:43:33 UTC 2017

On Fri, Jan 13, 2017, at 12:39, Niels de Vos wrote:
> On Wed, Jan 11, 2017 at 11:58:29AM -0700, Paul Allen wrote:
> > I'm running into an issue where the gluster nfs service keeps dying on a
> > new cluster I have setup recently. We've been using Gluster on several
> > other clusters now for about a year or so and I have never seen this
> > issue before, nor have I been able to find anything remotely similar to
> > it while searching on-line. I initially was using the latest version in
> > the Gluster Debian repository for Jessie, 3.9.0-1, and then I tried
> > using the next one down, 3.8.7-1. Both behave the same for me.
> > 
> > What I was seeing was after a while the nfs service on the NAS server
> > would suddenly die after a number of processes had run on the app server
> > I had connected to the new NAS servers for testing (we're upgrading the
> > NAS servers for this cluster to newer hardware and expanded storage, the
> > current production NAS servers are using nfs-kernel-server with no type
> > of clustering of the data). I checked the logs but all it showed me was
> > something that looked like a stack trace in the nfs.log and the
> > glustershd.log showed the nfs service disconnecting. I turned on
> > debugging but it didn't give me a whole lot more, and certainly nothing
> > that helps me identify the source of my issue. It is pretty consistent
> > in dying shortly after I mount the file system on the servers and start
> > testing, usually within 15-30 minutes. But if I have nothing using the
> > file system, mounted or no, the service stays running for days. I tried
> > mounting it using the gluster client, and it works fine, but I can;t use
> > that due to the performance penalty, it slows the websites down by a few
> > seconds at a minimum.
> 
> This seems to be related to the NLM protocol that Gluster/NFS provides.
> Earlier this week one of our Red Hat quality engineers also reported
> this (or a very similar) problem.
> 
> https://bugzilla.redhat.com/show_bug.cgi?id=1411344
> 
> At the moment I suspect that this is related to re-connects of some
> kind, but I have not been able to identify the cause sufficiently to be
> sure. This definitely is a coding problem in Gluster/NFS, but the more I
> look at the NLM implementation, the more potential issues I see with it.

Should we assume that, with the complete removal of Gluster/NFS already on the horizon, debugging and fixing NLM (even if only for the more common, reported crash cases) would be an extremely low-priority task? ;-)

Would it be possible for someone to simply check whether the crashes happen also on the 3.7.9-12 codebase used in latest RHGS 3.1.3?
My cluster is already at 3.7.12 feature level (and using it), so I suppose I could not easily downgrade.
Since Red Hat QA found a similar problem while testing the 3.8.4-10 codebase in RHGS 3.2.0, we could trace the problem back to post-3.7.9 developments, if RHGS 3.1.3 is immune.

> If the workload does not require locking operations, you may be able to
> work around the problem by mounting with "-o nolock". Depending on the
> application, this can be safe or cause data corruption...

If I'm not mistaken, typical NFS uses such as YUM repositories and home directories would be barred (I think that SQLite needs locking and both createrepo and firefox use SQLite, right?).

> An other alternative is to use NFS-Ganesha instead of Gluster/NFS.
> Ganesha is more mature than Gluster/NFS and is more actively developed.
> Gluster/NFS is being deprecated in favour of NFS-Ganesha.

Pure storage infrastructure uses should be migratable, I suppose, but extended testing and a suitable maintenance window (a rolling live migration from Gluster/NFS is not feasible, if I understood Ganesha right) would be needed anyway, I suppose.

More "extreme" uses (such as mine, unfortunately: hyperconverged Gluster+oVirt setup coexisting with full CIFS/NFS sharing services) have not been documented/considered for Ganesha, according to my own research on the case (but please correct me if I'm wrong).
Since I already envisioned such an outcome, I recently posted a request for info/directions on such a migration in my particular case:

http://lists.gluster.org/pipermail/gluster-users/2017-January/029650.html

Can anyone from the developers camp kindly comment on the above points? :-)

Many many thanks in advance.

Best regards,
Giuseppe

> HTH,
> Niels
> 
> 
> > 
> > Here is the output from the logs one of the times it died:
> > 
> > glustershd.log:
> > 
> > [2017-01-10 19:06:20.265918] W [socket.c:588:__socket_rwv] 0-nfs: readv
> > on /var/run/gluster/a921bec34928e8380280358a30865cee.socket failed (No
> > data available)
> > [2017-01-10 19:06:20.265964] I [MSGID: 106006]
> > [glusterd-svc-mgmt.c:327:glusterd_svc_common_rpc_notify] 0-management:
> > nfs has disconnected from glusterd.
> > 
> > 
> > nfs.log:
> > 
> > [2017-01-10 19:06:20.135430] D [name.c:168:client_fill_address_family]
> > 0-NLM-client: address-family not specified, marking it as unspec for
> > getaddrinfo to resolve from (remote-host: 10.20.5.13)
> > [2017-01-10 19:06:20.135531] D [MSGID: 0]
> > [common-utils.c:335:gf_resolve_ip6] 0-resolver: returning ip-10.20.5.13
> > (port-48963) for hostname: 10.20.5.13 and port: 48963
> > [2017-01-10 19:06:20.136569] D [logging.c:1764:gf_log_flush_extra_msgs]
> > 0-logging-infra: Log buffer size reduced. About to flush 5 extra log
> > messages
> > [2017-01-10 19:06:20.136630] D [logging.c:1767:gf_log_flush_extra_msgs]
> > 0-logging-infra: Just flushed 5 extra log messages
> > pending frames:
> > frame : type(0) op(0)
> > patchset: git://git.gluster.com/glusterfs.git
> > signal received: 11
> > time of crash:
> > 2017-01-10 19:06:20
> > configuration details:
> > argp 1
> > backtrace 1
> > dlfcn 1
> > libpthread 1
> > llistxattr 1
> > setfsid 1
> > spinlock 1
> > epoll.h 1
> > xattr.h 1
> > st_atim.tv_nsec 1
> > package-string: glusterfs 3.9.0
> > /usr/lib/x86_64-linux-gnu/libglusterfs.so.0(_gf_msg_backtrace_nomem+0xac)[0x7f891f0846ac]
> > /usr/lib/x86_64-linux-gnu/libglusterfs.so.0(gf_print_trace+0x324)[0x7f891f08dcc4]
> > /lib/x86_64-linux-gnu/libc.so.6(+0x350e0)[0x7f891db870e0]
> > /lib/x86_64-linux-gnu/libc.so.6(+0x91d8a)[0x7f891dbe3d8a]
> > /usr/lib/x86_64-linux-gnu/glusterfs/3.9.0/xlator/nfs/server.so(+0x3a352)[0x7f8918682352]
> > /usr/lib/x86_64-linux-gnu/glusterfs/3.9.0/xlator/nfs/server.so(+0x3cc15)[0x7f8918684c15]
> > /usr/lib/x86_64-linux-gnu/libgfrpc.so.0(rpc_clnt_notify+0x2aa)[0x7f891ee4e4da]
> > /usr/lib/x86_64-linux-gnu/libgfrpc.so.0(rpc_transport_notify+0x23)[0x7f891ee4a7e3]
> > /usr/lib/x86_64-linux-gnu/glusterfs/3.9.0/rpc-transport/socket.so(+0x4b33)[0x7f8919eadb33]
> > /usr/lib/x86_64-linux-gnu/glusterfs/3.9.0/rpc-transport/socket.so(+0x8f07)[0x7f8919eb1f07]
> > /usr/lib/x86_64-linux-gnu/libglusterfs.so.0(+0x7e836)[0x7f891f0d9836]
> > /lib/x86_64-linux-gnu/libpthread.so.0(+0x80a4)[0x7f891e3010a4]
> > /lib/x86_64-linux-gnu/libc.so.6(clone+0x6d)[0x7f891dc3a62d]
> > 
> > 
> > The IP showing in the nfs.log is actually for a web server I was also
> > testing with, not the app server, but it doesn't appear to me that would
> > be the cause for the nfs service dying. I'm at a loss as to what is
> > going on, and I need to try and get this fixed pretty quickly here, I
> > was hoping to have this in production last Friday. If anyone has any
> > ideas I'd be very grateful.
> > 
> > -- 
> > 
> > Paul Allen
> > 
> > Inetz System Administrator
> > 
> > 
> > _______________________________________________
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> > Gluster-users at gluster.org
> > http://www.gluster.org/mailman/listinfo/gluster-users
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