[Gluster-users] not to reconnect between client and server because of race condition

songxin songxin_1980 at 126.com
Fri Nov 25 07:19:17 UTC 2016


Hi Kaushal,
Thank you for your reply.
I will make sure whether this patch could fix my problem.


Thanks,
Xin








At 2016-11-25 14:57:56, "Kaushal M" <kshlmster at gmail.com> wrote:
>On Fri, Nov 25, 2016 at 12:03 PM, songxin <songxin_1980 at 126.com> wrote:
>> Hi Atin
>> I found a  problem, that is about client(glusterfs) will not trying to
>> reconnect to server(glusterfsd) after disconnect.
>> Actually, it seems caused by race condition.
>>
>>
>> Precondition
>>
>> The glusterfs version is 3.7.6.
>> I create a replicate volume using two node, A node and B node.One brick is
>> on A node and another brick is on B node.
>> A node ip:10.32.1.144
>> B node ip:10.32.0.48
>>
>>
>> The phenomenon is following.
>>
>> Firstly, the client(glusterfs) on A board disconnect with server(glusterfsd)
>> on B board.The log is following.
>> ...
>> readv on 10.32.0.48:49309 failed (No data available)
>> ...
>>
>> And then the client(glusterfs) on A board disconnect with server(glusterfsd)
>> on A board.The log is following.
>> ...
>> readv on 10.32.1.144:49391 failed (Connection reset by peer)
>> ...
>>
>> After that, all operation in mount point will show "Transport endpoint is
>> not connected" until client reconnect with server(glusterfsd) on B board.
>>
>>
>> The client log is following.And I have highlight the important line.
>> ...
>> [2016-10-31 04:06:03.626047] W [socket.c:588:__socket_rwv]
>> 0-c_glusterfs-client-9: readv on 10.32.1.144:49391 failed (Connection reset
>> by peer)
>> [2016-10-31 04:06:03.627345] E [rpc-clnt.c:362:saved_frames_unwind] (-->
>> /usr/lib64/libglusterfs.so.0(_gf_log_callingfn-0xb5c80)[0x3fff8ab79f58] (
>>                                                                      -->
>> /usr/lib64/libgfrpc.so.0(saved_frames_unwind-0x1b7a0)[0x3fff8ab1dc90] (
>>                                                                      -->
>> /usr/lib64/libgfrpc.so.0(saved_frames_destroy-0x1b638)[0x3fff8ab1de10] (
>>                                                                      -->
>> /usr/lib64/libgfrpc.so.0(rpc_clnt_connection_cleanup-0x19af8)[0x3fff8ab1fb18]
>> (
>>                                                                      -->
>> /usr/lib64/libgfrpc.so.0(rpc_clnt_notify-0x18e68)[0x3fff8ab20808] )))))
>>
>> 0-c_glusterfs-client-9: forced unwinding frame type(GlusterFS 3.3)
>>
>> op(FINODELK(30)) called at 2016-10-31 04:06:03.626033 (xid=0x7f5e)
>>
>> [2016-10-31 04:06:03.627395] E [MSGID: 114031]
>> [client-rpc-fops.c:1673:client3_3_finodelk_cbk] 0-c_glusterfs-client-9:
>> remote operation failed [Transport endpoint is not connected]
>>
>> [2016-10-31 04:06:03.628381] I [socket.c:3308:socket_submit_request]
>> 0-c_glusterfs-client-9: not connected (priv->connected = 0)
>>
>> [2016-10-31 04:06:03.628432] W [rpc-clnt.c:1586:rpc_clnt_submit]
>> 0-c_glusterfs-client-9: failed to submit rpc-request (XID: 0x7f5f Program:
>> GlusterFS 3.3, ProgVers: 330, Proc: 30) to rpc-transport
>> (c_glusterfs-client-9)
>>
>> [2016-10-31 04:06:03.628466] E [MSGID: 114031]
>> [client-rpc-fops.c:1673:client3_3_finodelk_cbk] 0-c_glusterfs-client-9:
>> remote operation failed [Transport endpoint is not connected]
>> [2016-10-31 04:06:03.628475] I [MSGID: 108019]
>> [afr-lk-common.c:1086:afr_lock_blocking] 0-c_glusterfs-replicate-0: unable
>> to lock on even one child
>>
>> [2016-10-31 04:06:03.628539] I [MSGID: 108019]
>> [afr-transaction.c:1224:afr_post_blocking_inodelk_cbk]
>> 0-c_glusterfs-replicate-0: Blocking inodelks failed.
>>
>> [2016-10-31 04:06:03.628630] W [fuse-bridge.c:1282:fuse_err_cbk]
>> 0-glusterfs-fuse: 20790: FLUSH() ERR => -1 (Transport endpoint is not
>> connected)
>> [2016-10-31 04:06:03.629149] E [rpc-clnt.c:362:saved_frames_unwind] (-->
>> /usr/lib64/libglusterfs.so.0(_gf_log_callingfn-0xb5c80)[0x3fff8ab79f58] (-->
>> /usr/lib64/libgfrpc.so.0(saved_frames_unwind-0x1b7a0)[0x3fff8ab1dc90] (-->
>> /usr/lib64/libgfrpc.so.0(saved_frames_destroy-0x1b638)[0x3fff8ab1de10] (-->
>> /usr/lib64/libgfrpc.so.0(rpc_clnt_connection_cleanup-0x19af8)[0x3fff8ab1fb18]
>> (--> /usr/lib64/libgfrpc.so.0(rpc_clnt_notify-0x18e68)[0x3fff8ab20808] )))))
>> 0-c_glusterfs-client-9: forced unwinding frame type(GlusterFS 3.3)
>> op(LOOKUP(27)) called at 2016-10-31 04:06:03.624346 (xid=0x7f5a)
>>
>> [2016-10-31 04:06:03.629183] I [rpc-clnt.c:1847:rpc_clnt_reconfig]
>> 0-c_glusterfs-client-9: changing port to 49391 (from 0)
>>
>> [2016-10-31 04:06:03.629210] W [MSGID: 114031]
>> [client-rpc-fops.c:2971:client3_3_lookup_cbk] 0-c_glusterfs-client-9: remote
>> operation failed. Path:
>> /loadmodules_norepl/CXC1725605_P93A001/cello/emasviews
>> (b0e5a94e-a432-4dce-b86f-a551555780a2) [Transport endpoint is not connected]
>> [2016-10-31 04:06:03.629266] I [socket.c:3308:socket_submit_request]
>> 0-c_glusterfs-client-9: not connected (priv->connected = 255)
>> [2016-10-31 04:06:03.629277] I [MSGID: 109063]
>> [dht-layout.c:702:dht_layout_normalize] 0-c_glusterfs-dht: Found anomalies
>> in /loadmodules_norepl/CXC1725605_P93A001/cello/emasviews (gfid =
>> b0e5a94e-a432-4dce-b86f-a551555780a2). Holes=1 overlaps=0
>> [2016-10-31 04:06:03.629293] W [rpc-clnt.c:1586:rpc_clnt_submit]
>> 0-c_glusterfs-client-9: failed to submit rpc-request (XID: 0x7f62 Program:
>> GlusterFS 3.3, ProgVers: 330, Proc: 41) to rpc-transport
>> (c_glusterfs-client-9)
>> [2016-10-31 04:06:03.629333] W [fuse-resolve.c:149:fuse_resolve_gfid_cbk]
>> 0-fuse: b0e5a94e-a432-4dce-b86f-a551555780a2: failed to resolve (Transport
>> endpoint is not connected)
>> [2016-10-31 04:06:03.629363] W [fuse-bridge.c:3385:fuse_getxattr_resume]
>> 0-glusterfs-fuse: 20784: GETXATTR
>> b0e5a94e-a432-4dce-b86f-a551555780a2/70366685109140
>> (system.posix_acl_access) resolution failed
>> [2016-10-31 04:06:03.629729] E [rpc-clnt.c:362:saved_frames_unwind] (-->
>> /usr/lib64/libglusterfs.so.0(_gf_log_callingfn-0xb5c80)[0x3fff8ab79f58] (-->
>> /usr/lib64/libgfrpc.so.0(saved_frames_unwind-0x1b7a0)[0x3fff8ab1dc90] (-->
>> /usr/lib64/libgfrpc.so.0(saved_frames_destroy-0x1b638)[0x3fff8ab1de10] (-->
>> /usr/lib64/libgfrpc.so.0(rpc_clnt_connection_cleanup-0x19af8)[0x3fff8ab1fb18]
>> (--> /usr/lib64/libgfrpc.so.0(rpc_clnt_notify-0x18e68)[0x3fff8ab20808] )))))
>> 0-c_glusterfs-client-9: forced unwinding frame type(GlusterFS 3.3)
>> op(LOOKUP(27)) called at 2016-10-31 04:06:03.624568 (xid=0x7f5b)
>> [2016-10-31 04:06:03.629779] W [MSGID: 114031]
>> [client-rpc-fops.c:2971:client3_3_lookup_cbk] 0-c_glusterfs-client-9: remote
>> operation failed. Path: /pmd/2 (fa866805-ab22-4afe-8acb-528d15ce4117)
>> [Transport endpoint is not connected]
>> [2016-10-31 04:06:03.629784] E [MSGID: 114031]
>> [client-rpc-fops.c:2883:client3_3_opendir_cbk] 0-c_glusterfs-client-9:
>> remote operation failed. Path:
>> /loadmodules_norepl/CXC1725605_P93A001/cello/emasviews
>> (b0e5a94e-a432-4dce-b86f-a551555780a2) [Transport endpoint is not connected]
>> [2016-10-31 04:06:03.629836] I [MSGID: 109063]
>> [dht-layout.c:702:dht_layout_normalize] 0-c_glusterfs-dht: Found anomalies
>> in /pmd/2 (gfid = fa866805-ab22-4afe-8acb-528d15ce4117). Holes=1 overlaps=0
>> [2016-10-31 04:06:03.629857] W [fuse-bridge.c:980:fuse_fd_cbk]
>> 0-glusterfs-fuse: 20794: OPENDIR()
>> /loadmodules_norepl/CXC1725605_P93A001/cello/emasviews => -1 (Transport
>> endpoint is not connected)
>> [2016-10-31 04:06:03.629896] W [fuse-resolve.c:149:fuse_resolve_gfid_cbk]
>> 0-fuse: fa866805-ab22-4afe-8acb-528d15ce4117: failed to resolve (Transport
>> endpoint is not connected)
>> [2016-10-31 04:06:03.629990] E [fuse-bridge.c:787:fuse_getattr_resume]
>> 0-glusterfs-fuse: 20785: GETATTR 70366685017568
>> (fa866805-ab22-4afe-8acb-528d15ce4117) resolution failed
>> [2016-10-31 04:06:03.630164] W [defaults.c:2212:default_releasedir]
>> (-->/usr/lib64/glusterfs/3.7.6/xlator/protocol/client.so(client_local_wipe-0x42d64)
>> [0x3fff86c9bc5c] -->/usr/lib64/libglusterfs.so.0(fd_unref-0x7ba98)
>> [0x3fff8abb7ad0] -->/usr/lib64/libglusterfs.so.0(default_releasedir-0x9d6d8)
>> [0x3fff8ab93c58] ) 0-fuse: xlator does not implement releasedir_cbk
>> [2016-10-31 04:06:03.630367] E [rpc-clnt.c:362:saved_frames_unwind] (-->
>> /usr/lib64/libglusterfs.so.0(_gf_log_callingfn-0xb5c80)[0x3fff8ab79f58] (-->
>> /usr/lib64/libgfrpc.so.0(saved_frames_unwind-0x1b7a0)[0x3fff8ab1dc90] (-->
>> /usr/lib64/libgfrpc.so.0(saved_frames_destroy-0x1b638)[0x3fff8ab1de10] (-->
>> /usr/lib64/libgfrpc.so.0(rpc_clnt_connection_cleanup-0x19af8)[0x3fff8ab1fb18]
>> (--> /usr/lib64/libgfrpc.so.0(rpc_clnt_notify-0x18e68)[0x3fff8ab20808] )))))
>> 0-c_glusterfs-client-9: forced unwinding frame type(GlusterFS 3.3)
>> op(LOOKUP(27)) called at 2016-10-31 04:06:03.625675 (xid=0x7f5c)
>> [2016-10-31 04:06:03.630368] W [MSGID: 114031]
>> [client-rpc-fops.c:1569:client3_3_fstat_cbk] 0-c_glusterfs-client-9: remote
>> operation failed [Transport endpoint is not connected]
>> [2016-10-31 04:06:03.630497] W [MSGID: 114031]
>> [client-rpc-fops.c:2971:client3_3_lookup_cbk] 0-c_glusterfs-client-9: remote
>> operation failed. Path: /configuration/oamrdncy.cfg
>> (200b0bb2-d903-4924-b025-262d805c0f2f) [Transport endpoint is not connected]
>> [2016-10-31 04:06:03.630871] I [MSGID: 114057]
>> [client-handshake.c:1437:select_server_supported_programs]
>> 0-c_glusterfs-client-9: Using Program GlusterFS 3.3, Num (1298437), Version
>> (330)
>>
>> [2016-10-31 04:06:03.631488] I [MSGID: 114046]
>> [client-handshake.c:1213:client_setvolume_cbk] 0-c_glusterfs-client-9:
>> Connected to c_glusterfs-client-9, attached to remote volume
>> '/opt/lvmdir/c2/brick'.
>>
>> [2016-10-31 04:06:03.631523] I [MSGID: 114047]
>> [client-handshake.c:1224:client_setvolume_cbk] 0-c_glusterfs-client-9:
>> Server and Client lk-version numbers are not same, reopening the fds
>> [2016-10-31 04:06:03.631555] I [MSGID: 114042]
>> [client-handshake.c:1056:client_post_handshake] 0-c_glusterfs-client-9: 6
>> fds open - Delaying child_up until they are re-opened
>> [2016-10-31 04:06:03.631475] W [MSGID: 114031]
>> [client-rpc-fops.c:2971:client3_3_lookup_cbk] 0-c_glusterfs-client-9: remote
>> operation failed. Path: /configuration/ethmac.cfg
>> (00000000-0000-0000-0000-000000000000) [Transport endpoint is not connected]
>> [2016-10-31 04:06:03.632256] I [MSGID: 114060]
>> [client-handshake.c:820:client3_3_reopendir_cbk] 0-c_glusterfs-client-9:
>> reopendir on <gfid:00000000-0000-0000-0000-000000000001> succeeded (fd = 1)
>> [2016-10-31 04:06:03.632728] I [MSGID: 114060]
>> [client-handshake.c:820:client3_3_reopendir_cbk] 0-c_glusterfs-client-9:
>> reopendir on <gfid:257add5a-9b87-4014-8a3a-09dd0a699eec> succeeded (fd = 2)
>> [2016-10-31 04:06:03.632790] I [MSGID: 114060]
>> [client-handshake.c:820:client3_3_reopendir_cbk] 0-c_glusterfs-client-9:
>> reopendir on <gfid:6fd47fe9-a566-47c7-8df7-e7a5e379101f> succeeded (fd = 3)
>> [2016-10-31 04:06:03.632847] I [MSGID: 114060]
>> [client-handshake.c:820:client3_3_reopendir_cbk] 0-c_glusterfs-client-9:
>> reopendir on <gfid:fa866805-ab22-4afe-8acb-528d15ce4117> succeeded (fd = 4)
>> [2016-10-31 04:06:03.632905] I [MSGID: 114060]
>> [client-handshake.c:820:client3_3_reopendir_cbk] 0-c_glusterfs-client-9:
>> reopendir on <gfid:139f5034-5b42-4fb8-9372-6dd7cac1e674> succeeded (fd = 5)
>> [2016-10-31 04:06:03.632935] I [MSGID: 114041]
>> [client-handshake.c:678:client_child_up_reopen_done] 0-c_glusterfs-client-9:
>> last fd open'd/lock-self-heal'd - notifying CHILD-UP
>>
>> [2016-10-31 04:06:03.633028] I [MSGID: 108005]
>> [afr-common.c:3841:afr_notify] 0-c_glusterfs-replicate-0: Subvolume
>> 'c_glusterfs-client-9' came back up; going online.
>>
>> [2016-10-31 04:06:03.633386] I [MSGID: 114035]
>> [client-handshake.c:193:client_set_lk_version_cbk] 0-c_glusterfs-client-9:
>> Server lk version = 1
>> [2016-10-31 04:06:03.634579] W [fuse-bridge.c:758:fuse_attr_cbk]
>> 0-glusterfs-fuse: 20795: FSTAT() /configuration/oamrdncy.cfg => -1
>> (Transport endpoint is not connected)
>> [2016-10-31 04:06:03.634889] E [rpc-clnt.c:362:saved_frames_unwind] (-->
>> /usr/lib64/libglusterfs.so.0(_gf_log_callingfn-0xb5c80)[0x3fff8ab79f58] (-->
>> /usr/lib64/libgfrpc.so.0(saved_frames_unwind-0x1b7a0)[0x3fff8ab1dc90] (-->
>> /usr/lib64/libgfrpc.so.0(saved_frames_destroy-0x1b638)[0x3fff8ab1de10] (-->
>> /usr/lib64/libgfrpc.so.0(rpc_clnt_connection_cleanup-0x19af8)[0x3fff8ab1fb18]
>> (--> /usr/lib64/libgfrpc.so.0(rpc_clnt_notify-0x18e68)[0x3fff8ab20808] )))))
>> 0-c_glusterfs-client-9: forced unwinding frame type(GlusterFS 3.3)
>> op(XATTROP(33)) called at 2016-10-31 04:06:03.625716 (xid=0x7f5d)
>> [2016-10-31 04:06:03.634950] W [MSGID: 114031]
>> [client-rpc-fops.c:1845:client3_3_xattrop_cbk] 0-c_glusterfs-client-9:
>> remote operation failed. Path: /configuration/oamrdncy.cfg
>> (200b0bb2-d903-4924-b025-262d805c0f2f)
>> [2016-10-31 04:06:03.635134] W [MSGID: 108008]
>> [afr-read-txn.c:250:afr_read_txn] 0-c_glusterfs-replicate-0: Unreadable
>> subvolume -1 found with event generation 3 for gfid
>> 200b0bb2-d903-4924-b025-262d805c0f2f. (Possible split-brain)
>> [2016-10-31 04:06:03.635364] I [MSGID: 114018]
>> [client.c:2042:client_rpc_notify] 0-c_glusterfs-client-9: disconnected from
>> c_glusterfs-client-9. Client process will keep trying to connect to glusterd
>> until brick's port is available
>> [2016-10-31 04:06:03.635420] E [MSGID: 108006]
>> [afr-common.c:3880:afr_notify] 0-c_glusterfs-replicate-0: All subvolumes are
>> down. Going offline until atleast one of them comes back up.
>> [2016-10-31 04:06:03.635762] I [MSGID: 108006]
>> [afr-common.c:4008:afr_local_init] 0-c_glusterfs-replicate-0: no subvolumes
>> up
>> [2016-10-31 04:06:03.641160] W [fuse-bridge.c:462:fuse_entry_cbk]
>> 0-glusterfs-fuse: 20808: LOOKUP() /license => -1 (Transport endpoint is not
>> connected)
>> The message "I [MSGID: 108006] [afr-common.c:4008:afr_local_init]
>> 0-c_glusterfs-replicate-0: no subvolumes up" repeated 6 times between
>> [2016-10-31 04:06:03.640564] and [2016-10-31 04:06:03.641444]
>> [2016-10-31 04:06:03.641484] E [MSGID: 114031]
>> [client-rpc-fops.c:1621:client3_3_inodelk_cbk] 0-c_glusterfs-client-9:
>> remote operation failed [Invalid argument]
>> [2016-10-31 04:06:03.641562] I [MSGID: 108006]
>> [afr-common.c:4008:afr_local_init] 0-c_glusterfs-replicate-0: no subvolumes
>> up
>> [2016-10-31 04:06:03.641573] E [MSGID: 108010]
>> [afr-lk-common.c:665:afr_unlock_inodelk_cbk] 0-c_glusterfs-replicate-0:
>> path=/configuration/oamrdncy.cfg gfid=200b0bb2-d903-4924-b025-262d805c0f2f:
>> unlock failed on subvolume c_glusterfs-client-9 with lock owner
>> 6cd0c189ff3f0000 [Invalid argument]
>> [2016-10-31 04:06:03.641655] I [MSGID: 108006]
>> [afr-common.c:4008:afr_local_init] 0-c_glusterfs-replicate-0: no subvolumes
>> up
>> [2016-10-31 04:06:03.641716] W [fuse-bridge.c:462:fuse_entry_cbk]
>> 0-glusterfs-fuse: 20809: LOOKUP() /lost+found => -1 (Transport endpoint is
>> not connected)
>> [2016-10-31 04:06:03.642387] W [fuse-bridge.c:462:fuse_entry_cbk]
>> 0-glusterfs-fuse: 20813: LOOKUP() /lost+found => -1 (Transport endpoint is
>> not connected)
>> ...
>>
>> Analysis
>>
>> I think the disconnection and reconnectiong between client(glusterfs on A
>> board) and server(glusterfsd on A board) has a race condition as below.
>>
>>
>> process 1
>> process 2
>>
>> [2016-10-31 04:06:03.626047]                                        readv
>> err show that
>>
>> the disconnect happen
>>
>> between client and server.
>>
>> [2016-10-31 04:06:03.627345]                                        It will
>> call rpc_clnt_notify().
>>
>> conn->connected = 0 in
>>
>> rpc_clnt_connection_cleanup.
>>
>> Creating a timer which will
>>
>> reconnect after 10 second.
>>
>>
>>
>> [2016-10-31 04:06:03.628381]
>> calling rpc_clnt_submit().
>>
>> it will call rpc_transport_connect
>>
>> because conn->connected is 0.
>>
>> [2016-10-31 04:06:03.631488]
>> the new connection has been successful.
>>
>>
>> [2016-10-31 04:06:03.633028]
>> calling  afr_notify(). In the case
>>
>> GF_EVENT_CHILD_UP  the new
>>
>> new connection is set by "priv->child_up[idx] = 1"
>>
>>
>> [2016-10-31 04:06:03.635364]                                      continue
>> to run client_rpc_notify()
>>
>> will notify RPC_CLNT_DISCONNECT
>>
>> in case RPC_CLNT_DISCONNECT.
>>
>> [2016-10-31 04:06:03.635420]                                      In
>> afr_notify() will set "priv->child_up[idx] = 0",
>>
>> which is the new connection,
>>
>> in the case RPC_CLNT_DISCONNECT.
>>
>> And the all the subvolume is down.
>>
>> [2016-10-31 04:06:03.635762]                                       All the
>> access will be failed because
>>
>> no subvolumes up.And rpc_transport_connect()
>>
>> will not be called  because the conn->connected
>>
>> has been set to 1 in process  2
>>
>>
>> Please help me to check my analysis.
>>
>> Thanks,
>> Xin
>>
>
>Awesome! You root caused this on your own. This exact same issue was
>root caused recently and we have a pending patch for it [1]. Expect
>this to be fixed soon.
>
>[1]: https://review.gluster.org/15916
>
>>
>>
>>
>>
>> _______________________________________________
>> Gluster-users mailing list
>> Gluster-users at gluster.org
>> http://www.gluster.org/mailman/listinfo/gluster-users
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