[Gluster-users] Unable to make HA work; mounts hang on remote node reboot

Mon Apr 27 19:59:57 UTC 2015

FYI, I’ve tried with both glusterfs and NFS mounts, and the reaction is the same. The value of ping.timeout seems to have no effect at all.

I did discover one thing that makes a difference on reboot. There is a second service descriptor for “glusterfsd”, which is not enabled by default, but is started by something else (glusterd, I assume?). However, whatever it is that starts the process, does not shut it down cleanly during a reboot… and it appears to be the loss of that process without de-registration in the peer group that causes the other nodes to hang. If I enable the service (chkconfig glusterfsd on), it does nothing by default because the config is commented out (/etc/sysconfig/glusterfsd). But, having those K scripts in place in rc.d, I can manually touch /var/lock/subsys/glusterfsd, and then I can successfully reboot one node without the others hanging. This at least helps when I need to take a node down for maintenance; it obviously still does nothing for a true node failure.

I guess my next step is to figure out to modify the init scripts for glusterd to touch the other lock file on startup as well. Does not seem a very elegant solution, but having the lock file in place and the init scripts enabled seems to solve at least half of the issue.

—CJ

> On Apr 25, 2015, at 11:34 AM, Corey Kovacs <corey.kovacs at gmail.com> wrote:
> 
> That's not cool..you certainly have a quorum. are you using the fuse client or regular old nfs?
> 
> C
> 
> On Apr 24, 2015 4:50 PM, "CJ Baar" <gsml at ffisys.com <mailto:gsml at ffisys.com>> wrote:
> Corey—
> I was able to get a third node setup. I recreated the volume as “replica 3”. The hang still happens (on two nodes, now) when I reboot a single node, even though two are still surviving, which should constitute a quorum.
> —CJ
> 
> 
>> On Apr 17, 2015, at 6:18 AM, Corey Kovacs <corey.kovacs at gmail.com <mailto:corey.kovacs at gmail.com>> wrote:
>> 
>> Typically you need to meet a quorum requirement to run just about any cluster.  By definition,  two nodes doesn't make a good cluster. A third node would let you start with just two since that would allow you to meet quorum. Can you add a third node to at least test?
>> 
>> Corey
>> 
>> On Apr 16, 2015 6:52 PM, "CJ Baar" <gsml at ffisys.com <mailto:gsml at ffisys.com>> wrote:
>> I appreciate the info. I have tried adjust the ping-timeout setting, and it has seems to have no effect. The whole system hangs for 45+ seconds, which is about what it takes the second node to reboot, no matter what the value of ping-timeout is.  The output of the mnt-log is below.  It shows the adjust value I am currently testing (30s), but the system still hangs for longer than that.
>> 
>> Also, I have realized that the problem is deeper than I originally thought.  It’s not just the mount that is hanging when a node reboots… it appears to be the entire system.  I cannot use my SSH connection, no matter where I am in the system, and services such as httpd become unresponsive.  I can ping the “surviving” system, but other than that it appears pretty unusable.  This is a major drawback to using gluster.  I can’t afford to lost two entire systems if one dies.
>> 
>> [2015-04-16 22:59:21.281365] C [rpc-clnt-ping.c:109:rpc_clnt_ping_timer_expired] 0-common-client-0: server 172.31.64.200:49152 <http://172.31.64.200:49152/> has not responded in the last 30 seconds, disconnecting.
>> [2015-04-16 22:59:21.281560] E [rpc-clnt.c:362:saved_frames_unwind] (--> /usr/lib64/libglusterfs.so.0(_gf_log_callingfn+0x1e0)[0x7fce96450550] (--> /usr/lib64/libgfrpc.so.0(saved_frames_unwind+0x1e7)[0x7fce96225787] (--> /usr/lib64/libgfrpc.so.0(saved_frames_destroy+0xe)[0x7fce9622589e] (--> /usr/lib64/libgfrpc.so.0(rpc_clnt_connection_cleanup+0x91)[0x7fce96225951] (--> /usr/lib64/libgfrpc.so.0(rpc_clnt_notify+0x15f)[0x7fce96225f1f] ))))) 0-common-client-0: forced unwinding frame type(GlusterFS 3.3) op(LOOKUP(27)) called at 2015-04-16 22:58:45.830962 (xid=0x6d)
>> [2015-04-16 22:59:21.281588] W [client-rpc-fops.c:2766:client3_3_lookup_cbk] 0-common-client-0: remote operation failed: Transport endpoint is not connected. Path: / (00000000-0000-0000-0000-000000000001)
>> [2015-04-16 22:59:21.281788] E [rpc-clnt.c:362:saved_frames_unwind] (--> /usr/lib64/libglusterfs.so.0(_gf_log_callingfn+0x1e0)[0x7fce96450550] (--> /usr/lib64/libgfrpc.so.0(saved_frames_unwind+0x1e7)[0x7fce96225787] (--> /usr/lib64/libgfrpc.so.0(saved_frames_destroy+0xe)[0x7fce9622589e] (--> /usr/lib64/libgfrpc.so.0(rpc_clnt_connection_cleanup+0x91)[0x7fce96225951] (--> /usr/lib64/libgfrpc.so.0(rpc_clnt_notify+0x15f)[0x7fce96225f1f] ))))) 0-common-client-0: forced unwinding frame type(GF-DUMP) op(NULL(2)) called at 2015-04-16 22:58:51.277528 (xid=0x6e)
>> [2015-04-16 22:59:21.281806] W [rpc-clnt-ping.c:154:rpc_clnt_ping_cbk] 0-common-client-0: socket disconnected
>> [2015-04-16 22:59:21.281816] I [client.c:2215:client_rpc_notify] 0-common-client-0: disconnected from common-client-0. Client process will keep trying to connect to glusterd until brick's port is available
>> [2015-04-16 22:59:21.283637] I [socket.c:3292:socket_submit_request] 0-common-client-0: not connected (priv->connected = 0)
>> [2015-04-16 22:59:21.283663] W [rpc-clnt.c:1562:rpc_clnt_submit] 0-common-client-0: failed to submit rpc-request (XID: 0x6f Program: GlusterFS 3.3, ProgVers: 330, Proc: 27) to rpc-transport (common-client-0)
>> [2015-04-16 22:59:21.283674] W [client-rpc-fops.c:2766:client3_3_lookup_cbk] 0-common-client-0: remote operation failed: Transport endpoint is not connected. Path: /src (63fc077b-869d-4928-8819-a79cc5c5ffa6)
>> [2015-04-16 22:59:21.284219] W [client-rpc-fops.c:2766:client3_3_lookup_cbk] 0-common-client-0: remote operation failed: Transport endpoint is not connected. Path: (null) (00000000-0000-0000-0000-000000000000)
>> [2015-04-16 22:59:52.322952] E [client-handshake.c:1496:client_query_portmap_cbk] 0-common-client-0: failed to get the port number for [root at cfm-c glusterfs]#
>> 
>> 
>> —CJ
>> 
>> 
>> 
>>> On Apr 7, 2015, at 10:26 PM, Ravishankar N <ravishankar at redhat.com <mailto:ravishankar at redhat.com>> wrote:
>>> 
>>> 
>>> 
>>> On 04/07/2015 10:11 PM, CJ Baar wrote:
>>>> Then, I issue “init 0” on node2, and the mount on node1 becomes unresponsive. This is the log from node1
>>>> [2015-04-07 16:36:04.250693] W [glusterd-op-sm.c:4021:glusterd_op_modify_op_ctx] 0-management: op_ctx modification failed
>>>> [2015-04-07 16:36:04.251102] I [glusterd-handler.c:3803:__glusterd_handle_status_volume] 0-management: Received status volume req for volume test1
>>>> The message "I [MSGID: 106004] [glusterd-handler.c:4365:__glusterd_peer_rpc_notify] 0-management: Peer 1069f037-13eb-458e-a9c4-0e7e79e595d0, in Peer in Cluster state, has disconnected from glusterd." repeated 39 times between [2015-04-07 16:34:40.609878] and [2015-04-07 16:36:37.752489]
>>>> [2015-04-07 16:36:40.755989] I [MSGID: 106004] [glusterd-handler.c:4365:__glusterd_peer_rpc_notify] 0-management: Peer 1069f037-13eb-458e-a9c4-0e7e79e595d0, in Peer in Cluster state, has disconnected from glusterd.
>>> This is the glusterd log. Could you also share the mount log of the healthy node in the non-responsive -->responsive time interval?
>>> If this is indeed the ping timer issue, you should see something like: "server xxx has not responded in the last 42 seconds, disconnecting."
>>> Have you, for testing sake, tried reducing the network.ping-timeout value to something lower and checked that the hang happens only for that time?
>>>> 
>>>> This does not seem like desired behaviour. I was trying to create this cluster because I was under the impression it would be more resilient than a single-point-of-failure NFS server. However, if the mount halts when one node in the cluster dies, then I’m no better off.
>>>> 
>>>> I also can’t seem to figure out how to bring a volume online if only one node in the cluster is running; again, not really functioning as HA. The gluster service runs and the volume “starts”, but it is not “online” or mountable until both nodes are running. In a situation where a node fails and we need storage online before we can troubleshoot the cause of the node failure, how do I get a volume to go online?
>>> This is expected behavior. In a two node cluster, if only one is powered on, glusterd will not start other gluster processes (brick, nfs, shd ) until the glusterd of the other node is also up (i.e. quorum is met). If you want to override this behavior, do a `gluster vol start <volname> force` on the node that is up.
>>> 
>>> -Ravi
>>>> 
>>>> Thanks.
>>> 
>> 
>> 
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