[Gluster-devel] atomic operations fails_

Tue Feb 9 20:28:52 UTC 2010

Haha, I love how you named your server! I think a lot of us feel the same
way :)

On Tue, Feb 9, 2010 at 11:18 AM, Fredrik Widlund <fredrik.widlund at qbrick.com
> wrote:

>
>  Hi,
>
>
>
> I’ll try to make myself clearer than in the earlier thread, since I need
> some help here. I’m not sure if I am missing something.
>
>
>
> I am not able to use atomic operations using glusterfs 3.0.2, on a Arch
> Linux 2.6.32.7-1 x86_64 server.
>
>
>
> I’ve stripped everything down to the most simple configuration
>
> Server: a posix store with locks
>
> Client: a tcp client
>
>
>
> I mount the glusterfs on /gfs, and use a “writer” and a “reader” as below:
>
> [writer]                root at frustration> while :; do date > /gfs/.file;
> mv /gfs/.file /gfs/file; done
>
> [reader]               root at frustration> while :; do cat /gfs/file >
> /dev/null; done
>
>
>
> Leaving this running, I get a flood of
>
> cat: /gfs/file: No such file or directory
>
>
>
> This should not happen on a filesystem that supports atomic operations?!
>
>
>
> What this means is that I am unable to replace a file as an atomic
> operation, creating a race-condition where the file is sometimes not
> present. Furthermore this actually “desyncs” the server in a more complex
> setup, requiring a restart of the server part to make “desynced” files
> available again.
>
>
>
> This reproduces using XFS as well as EXT2 as the underlying fs.
>
>
>
> [glusterfs.vol]
>
> volume media0
>
>   type protocol/client
>
>   option transport-type tcp
>
>   option remote-host 127.0.0.1
>
>   option remote-subvolume media0
>
> end-volume
>
>
>
> mounted with “glusterfs -f glusterfs.vol /gfs”
>
>
>
> [glusterfsd.vol]
>
> (se below debug log)
>
>
>
> -x-
>
>
>
> [2010-02-09 18:18:23] D [glusterfsd.c:424:_get_specfp] glusterfs: loading
> volume file glusterfsd.vol
>
> [2010-02-09 18:18:23] D [xlator.c:739:xlator_set_type] xlator:
> dlsym(notify) on /usr/lib/glusterfs/3.0.2/xlator/features/locks.so:
> undefined symbol: notify -- neglecting
>
>
> ================================================================================
>
> Version      : glusterfs 3.0.2 built on Feb  8 2010 15:23:34
>
> git: v3.0.2
>
> Starting Time: 2010-02-09 18:18:23
>
> Command line : glusterfs -f glusterfsd.vol --debug
>
> PID          : 19486
>
> System name  : Linux
>
> Nodename     : n100.p1.x0.local
>
> Kernel Release : 2.6.32-ARCH
>
> Hardware Identifier: x86_64
>
>
>
> Given volfile:
>
>
> +------------------------------------------------------------------------------+
>
>   1: volume media0-store
>
>   2:   type storage/posix
>
>   3:   option directory /mnt
>
>   4: end-volume
>
>   5:
>
>   6: volume media0
>
>   7:   type features/locks
>
>   8:   subvolumes media0-store
>
>   9: end-volume
>
>  10:
>
>  11: volume server
>
>  12:   type protocol/server
>
>  13:   option transport-type tcp
>
>  14:   option auth.addr.media0.allow *
>
>  15:   subvolumes media0
>
>  16: end-volume
>
>
>
>
> +------------------------------------------------------------------------------+
>
> [2010-02-09 18:18:23] D [glusterfsd.c:1370:main] glusterfs: running in pid
> 19486
>
> [2010-02-09 18:18:23] D [transport.c:145:transport_load] transport: attempt
> to load file /usr/lib/glusterfs/3.0.2/transport/socket.so
>
> [2010-02-09 18:18:23] N [glusterfsd.c:1396:main] glusterfs: Successfully
> started
>
> [2010-02-09 18:18:43] D [addr.c:190:gf_auth] media0: allowed = "*",
> received addr = "127.0.0.1"
>
> [2010-02-09 18:18:43] N [server-protocol.c:5812:mop_setvolume] server:
> accepted client from 127.0.0.1:1023
>
> [2010-02-09 18:18:43] D [addr.c:190:gf_auth] media0: allowed = "*",
> received addr = "127.0.0.1"
>
> [2010-02-09 18:18:43] N [server-protocol.c:5812:mop_setvolume] server:
> accepted client from 127.0.0.1:1022
>
> [2010-02-09 18:18:58] D [server-resolve.c:238:resolve_path_deep] media0:
> RESOLVE RENAME() seeking deep resolution of /file
>
> [2010-02-09 18:18:58] D [dict.c:303:dict_get] dict: @this=(nil)
> @key=0x7f2a38a9f79b
>
> [2010-02-09 18:18:58] D [dict.c:303:dict_get] dict: @this=(nil)
> @key=0x7f2a38a9f7b3
>
> [2010-02-09 18:18:58] D [dict.c:303:dict_get] dict: @this=(nil)
> @key=0x7f2a38a9f7cb
>
> [2010-02-09 18:18:58] D [dict.c:303:dict_get] dict: @this=(nil)
> @key=0x7f2a38a9f79b
>
> [2010-02-09 18:18:58] D [dict.c:303:dict_get] dict: @this=(nil)
> @key=0x7f2a38a9f7b3
>
> [2010-02-09 18:18:58] D [dict.c:303:dict_get] dict: @this=(nil)
> @key=0x7f2a38a9f7cb
>
> [2010-02-09 18:19:15] D [inode.c:916:inode_path] media0/inode: no dentry
> for non-root inode 502725
>
> [2010-02-09 18:19:34] D [inode.c:916:inode_path] media0/inode: no dentry
> for non-root inode 502734
>
> [2010-02-09 18:19:56] D [inode.c:916:inode_path] media0/inode: no dentry
> for non-root inode 502734
>
> […] repeated many times. Frequency of the “no dentry” entries depends on
> how aggressive the reader is.
>
>
>
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>
>
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