On Tue, Nov 15, 2016 at 12:47 PM, songxin <songxin_1980 at 126.com> wrote:
>
> Hi Atin,
>
> I think the root cause is in the function glusterd_import_friend_volume as
> below.
>
> int32_t
> glusterd_import_friend_volume (dict_t *peer_data, size_t count)
> {
> ...
> ret = glusterd_volinfo_find (new_volinfo->volname,
&old_volinfo);
> if (0 == ret) {
> (void) gd_check_and_update_rebalance_info (old_volinfo,
> new_volinfo);
> (void) glusterd_delete_stale_volume (old_volinfo,
> new_volinfo);
> }
> ...
> ret = glusterd_store_volinfo (new_volinfo,
> GLUSTERD_VOLINFO_VER_AC_NONE);
> if (ret) {
> gf_msg (this->name, GF_LOG_ERROR, 0,
> GD_MSG_VOLINFO_STORE_FAIL, "Failed to store
"
> "volinfo for volume %s",
new_volinfo->volname);
> goto out;
> }
> ...
> }
>
> glusterd_delete_stale_volume will remove the info and bricks/* and the
> glusterd_store_volinfo will create the new one.
> But if glusterd is killed before rename the info will is empty.
>
> And glusterd will start failed because the infois empty in the next time
> you start the glusterd.
>
> Any idea? Atin?
>
Give me some time, will check it out, but reading at this analysis looks
very well possible if a volume is changed when the glusterd was done on
node a and when the same comes up during peer handshake we update the
volinfo and during that time glusterd goes down once again. I'll confirm it
by tomorrow.
BTW, excellent work Xin!
> Thanks,
> Xin
>
>
> ? 2016-11-15 12:07:05?"Atin Mukherjee" <amukherj at
redhat.com> ???
>
>
>
> On Tue, Nov 15, 2016 at 8:58 AM, songxin <songxin_1980 at 126.com>
wrote:
>
>> Hi Atin,
>> I have some clues about this issue.
>> I could reproduce this issue use the scrip that mentioned in
>> https://bugzilla.redhat.com/show_bug.cgi?id=1308487 .
>>
>
> I really appreciate your help in trying to nail down this issue. While I
> am at your email and going through the code to figure out the possible
> cause for it, unfortunately I don't see any script in the attachment of
the
> bug. Could you please cross check?
>
>
>>
>> After I added some debug print,which like below, in glusterd-store.c
and
>> I found that the /var/lib/glusterd/vols/xxx/info and
>> /var/lib/glusterd/vols/xxx/bricks/* are removed.
>> But other files in /var/lib/glusterd/vols/xxx/ will not be remove.
>>
>> int32_t
>> glusterd_store_volinfo (glusterd_volinfo_t *volinfo,
>> glusterd_volinfo_ver_ac_t ac)
>> {
>> int32_t ret = -1;
>>
>> GF_ASSERT (volinfo)
>>
>> ret = access("/var/lib/glusterd/vols/gv0/info",
F_OK);
>> if(ret < 0)
>> {
>> gf_msg (THIS->name, GF_LOG_ERROR, 0, 0, "info
is not
>> exit(%d)", errno);
>> }
>> else
>> {
>> ret = stat("/var/lib/glusterd/vols/gv0/info",
&buf);
>> if(ret < 0)
>> {
>> gf_msg (THIS->name, GF_LOG_ERROR, 0, 0,
"stat
>> info error");
>> }
>> else
>> {
>> gf_msg (THIS->name, GF_LOG_ERROR, 0, 0,
"info
>> size is %lu, inode num is %lu", buf.st_size, buf.st_ino);
>> }
>> }
>>
>> glusterd_perform_volinfo_version_action (volinfo, ac);
>> ret = glusterd_store_create_volume_dir (volinfo);
>> if (ret)
>> goto out;
>>
>> ...
>> }
>>
>> So it is easy to understand why the info or
10.32.1.144.-opt-lvmdir-c2-
>> brick sometimes is empty.
>> It is becaue the info file is not exist, and it will be create by ?fd
>> open (path, O_RDWR | O_CREAT | O_APPEND, 0600);? in function
>> gf_store_handle_new.
>> And the info file is empty before rename.
>> So the info file is empty if glusterd shutdown before rename.
>>
>>
>
>> My question is following.
>> 1.I did not find the point the info is removed.Could you tell me the
>> point where the info and /bricks/* are removed?
>> 2.why the file info and bricks/* is removed?But other files in
var/lib/glusterd/vols/xxx/
>> are not be removed?
>>
>
> AFAIK, we never delete the info file and hence this file is opened with
> O_APPEND flag. As I said I will go back and cross check the code once
again.
>
>
>
>
>> Thanks,
>> Xin
>>
>>
>> ? 2016-11-11 20:34:05?"Atin Mukherjee" <amukherj at
redhat.com> ???
>>
>>
>>
>> On Fri, Nov 11, 2016 at 4:00 PM, songxin <songxin_1980 at
126.com> wrote:
>>
>>> Hi Atin,
>>>
>>> Thank you for your support.
>>> Sincerely wait for your reply.
>>>
>>> By the way, could you make sure that the issue, file info is empty,
>>> cause by rename is interrupted in kernel?
>>>
>>
>> As per my RCA on that bug, it looked to be.
>>
>>
>>>
>>> Thanks,
>>> Xin
>>>
>>> ? 2016-11-11 15:49:02?"Atin Mukherjee" <amukherj at
redhat.com> ???
>>>
>>>
>>>
>>> On Fri, Nov 11, 2016 at 1:15 PM, songxin <songxin_1980 at
126.com> wrote:
>>>
>>>> Hi Atin,
>>>> Thank you for your reply.
>>>> Actually it is very difficult to reproduce because I don't
know when there
>>>> was an ongoing commit happening.It is just a coincidence.
>>>> But I want to make sure the root cause.
>>>>
>>>
>>> I'll give it a another try and see if this situation can be
>>> simulated/reproduced and will keep you posted.
>>>
>>>
>>>>
>>>> So I would be grateful if you could answer my questions below.
>>>>
>>>> You said that "This issue is hit at part of the negative
testing where
>>>> while gluster volume set was executed at the same point of time
glusterd in
>>>> another instance was brought down. In the faulty node we could
see
>>>> /var/lib/glusterd/vols/<volname>info file been empty
whereas the
>>>> info.tmp file has the correct contents." in comment.
>>>>
>>>> I have two questions for you.
>>>>
>>>> 1.Could you reproduce this issue by gluster volume set glusterd
which was brought down?
>>>> 2.Could you be certain that this issue is cause by rename is
interrupted in kernel?
>>>>
>>>> In my case there are two files, info and
10.32.1.144.-opt-lvmdir-c2-brick, are both empty.
>>>> But in my view only one rename can be running at the same time
because of the big lock.
>>>> Why there are two files are empty?
>>>>
>>>>
>>>> Could rename("info.tmp", "info") and
rename("xxx-brick.tmp", "xxx-brick") be running in two
thread?
>>>>
>>>> Thanks,
>>>> Xin
>>>>
>>>>
>>>> ? 2016-11-11 15:27:03?"Atin Mukherjee" <amukherj
at redhat.com> ???
>>>>
>>>>
>>>>
>>>> On Fri, Nov 11, 2016 at 12:38 PM, songxin <songxin_1980 at
126.com> wrote:
>>>>
>>>>>
>>>>> Hi Atin,
>>>>> Thank you for your reply.
>>>>>
>>>>> As you said that the info file can only be changed in the
glusterd_store_volinfo()
>>>>> sequentially because of the big lock.
>>>>>
>>>>> I have found the similar issue as below that you mentioned.
>>>>> https://bugzilla.redhat.com/show_bug.cgi?id=1308487
>>>>>
>>>>
>>>> Great, so this is what I was actually trying to refer in my
first email
>>>> that I saw a similar issue. Have you got a chance to look at
>>>> https://bugzilla.redhat.com/show_bug.cgi?id=1308487#c4 ? But in
your
>>>> case, did you try to bring down glusterd when there was an
ongoing commit
>>>> happening?
>>>>
>>>>
>>>>>
>>>>> You said that "This issue is hit at part of the
negative testing where
>>>>> while gluster volume set was executed at the same point of
time glusterd in
>>>>> another instance was brought down. In the faulty node we
could see
>>>>> /var/lib/glusterd/vols/<volname>info file been empty
whereas the
>>>>> info.tmp file has the correct contents." in comment.
>>>>>
>>>>> I have two questions for you.
>>>>>
>>>>> 1.Could you reproduce this issue by gluster volume set
glusterd which was brought down?
>>>>> 2.Could you be certain that this issue is cause by rename
is interrupted in kernel?
>>>>>
>>>>> In my case there are two files, info and
10.32.1.144.-opt-lvmdir-c2-brick, are both empty.
>>>>> But in my view only one rename can be running at the same
time because of the big lock.
>>>>> Why there are two files are empty?
>>>>>
>>>>>
>>>>> Could rename("info.tmp", "info") and
rename("xxx-brick.tmp", "xxx-brick") be running in two
thread?
>>>>>
>>>>> Thanks,
>>>>> Xin
>>>>>
>>>>>
>>>>>
>>>>>
>>>>> ? 2016-11-11 14:36:40?"Atin Mukherjee"
<amukherj at redhat.com> ???
>>>>>
>>>>>
>>>>>
>>>>> On Fri, Nov 11, 2016 at 8:33 AM, songxin <songxin_1980
at 126.com> wrote:
>>>>>
>>>>>> Hi Atin,
>>>>>>
>>>>>> Thank you for your reply.
>>>>>> I have two questions for you.
>>>>>>
>>>>>> 1.Are the two files info and info.tmp are only to be
created or
>>>>>> changed in function glusterd_store_volinfo()? I did not
find other point in
>>>>>> which the two file are changed.
>>>>>>
>>>>>
>>>>> If we are talking about info file volume then yes, the
mentioned
>>>>> function actually takes care of it.
>>>>>
>>>>>
>>>>>> 2.I found that glusterd_store_volinfo() will be call in
many point
>>>>>> by glusterd.Is there a problem of thread
synchronization?If so, one thread
>>>>>> may open a same file info.tmp using O_TRUNC flag when
another thread
>>>>>> is writing the info,tmp.Could this case happen?
>>>>>>
>>>>>
>>>>> In glusterd threads are big lock protected and I don't
see a
>>>>> possibility (theoretically) to have two
glusterd_store_volinfo () calls at
>>>>> a given point of time.
>>>>>
>>>>>
>>>>>>
>>>>>> Thanks,
>>>>>> Xin
>>>>>>
>>>>>>
>>>>>> At 2016-11-10 21:41:06, "Atin Mukherjee"
<amukherj at redhat.com> wrote:
>>>>>>
>>>>>> Did you run out of disk space by any chance? AFAIK, the
code is like
>>>>>> we write new stuffs to .tmp file and rename it back to
the original file.
>>>>>> In case of a disk space issue I expect both the files
to be of non zero
>>>>>> size. But having said that I vaguely remember a similar
issue (in the form
>>>>>> of a bug or an email) landed up once but we
couldn't reproduce it, so
>>>>>> something is wrong with the atomic update here is what
I guess. I'll be
>>>>>> glad if you have a reproducer for the same and then we
can dig into it
>>>>>> further.
>>>>>>
>>>>>> On Thu, Nov 10, 2016 at 1:32 PM, songxin
<songxin_1980 at 126.com>
>>>>>> wrote:
>>>>>>
>>>>>>> Hi,
>>>>>>> When I start the glusterd some error happened.
>>>>>>> And the log is following.
>>>>>>>
>>>>>>> [2016-11-08 07:58:34.989365] I [MSGID: 100030]
>>>>>>> [glusterfsd.c:2318:main] 0-/usr/sbin/glusterd:
Started running
>>>>>>> /usr/sbin/glusterd version 3.7.6 (args:
/usr/sbin/glusterd -p
>>>>>>> /var/run/glusterd.pid --log-level INFO)
>>>>>>> [2016-11-08 07:58:34.998356] I [MSGID: 106478]
>>>>>>> [glusterd.c:1350:init] 0-management: Maximum
allowed open file descriptors
>>>>>>> set to 65536
>>>>>>> [2016-11-08 07:58:35.000667] I [MSGID: 106479]
>>>>>>> [glusterd.c:1399:init] 0-management: Using
/system/glusterd as working
>>>>>>> directory
>>>>>>> [2016-11-08 07:58:35.024508] I [MSGID: 106514]
>>>>>>> [glusterd-store.c:2075:glusterd_restore_op_version]
0-management:
>>>>>>> Upgrade detected. Setting op-version to minimum : 1
>>>>>>> *[2016-11-08 07:58:35.025356] E [MSGID: 106206]
>>>>>>>
[glusterd-store.c:2562:glusterd_store_update_volinfo] 0-management: Failed
>>>>>>> to get next store iter *
>>>>>>> *[2016-11-08 07:58:35.025401] E [MSGID: 106207]
>>>>>>>
[glusterd-store.c:2844:glusterd_store_retrieve_volume] 0-management: Failed
>>>>>>> to update volinfo for c_glusterfs volume *
>>>>>>> *[2016-11-08 07:58:35.025463] E [MSGID: 106201]
>>>>>>>
[glusterd-store.c:3042:glusterd_store_retrieve_volumes] 0-management:
>>>>>>> Unable to restore volume: c_glusterfs *
>>>>>>> *[2016-11-08 07:58:35.025544] E [MSGID: 101019]
>>>>>>> [xlator.c:428:xlator_init] 0-management:
Initialization of volume
>>>>>>> 'management' failed, review your volfile
again *
>>>>>>> *[2016-11-08 07:58:35.025582] E
[graph.c:322:glusterfs_graph_init]
>>>>>>> 0-management: initializing translator failed *
>>>>>>> *[2016-11-08 07:58:35.025629] E
>>>>>>> [graph.c:661:glusterfs_graph_activate] 0-graph:
init failed *
>>>>>>> [2016-11-08 07:58:35.026109] W
[glusterfsd.c:1236:cleanup_and_exit]
>>>>>>>
(-->/usr/sbin/glusterd(glusterfs_volumes_init-0x1b260) [0x1000a718]
>>>>>>>
-->/usr/sbin/glusterd(glusterfs_process_volfp-0x1b3b8) [0x1000a5a8]
>>>>>>> -->/usr/sbin/glusterd(cleanup_and_exit-0x1c02c)
[0x100098bc] ) 0-:
>>>>>>> received signum (0), shutting down
>>>>>>>
>>>>>>>
>>>>>>> And then I found that the size of
vols/volume_name/info is 0.It
>>>>>>> cause glusterd shutdown.
>>>>>>> But I found that vols/volume_name_info.tmp is not
0.
>>>>>>> And I found that there is a brick file
vols/volume_name/bricks/xxxx.brick
>>>>>>> is 0, but vols/volume_name/bricks/xxxx.brick.tmp is
not 0.
>>>>>>>
>>>>>>> I read the function code glusterd_store_volinfo ()
in
>>>>>>> glusterd-store.c .
>>>>>>> I know that the info.tmp will be rename to info in
function
>>>>>>> glusterd_store_volume_atomic_update().
>>>>>>>
>>>>>>> But my question is that why the info file is 0 but
info.tmp is not 0.
>>>>>>>
>>>>>>>
>>>>>>> Thanks,
>>>>>>> Xin
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>> _______________________________________________
>>>>>>> Gluster-users mailing list
>>>>>>> Gluster-users at gluster.org
>>>>>>>
http://www.gluster.org/mailman/listinfo/gluster-users
>>>>>>>
>>>>>>
>>>>>>
>>>>>>
>>>>>> --
>>>>>>
>>>>>> ~ Atin (atinm)
>>>>>>
>>>>>>
>>>>>>
>>>>>>
>>>>>>
>>>>>
>>>>>
>>>>>
>>>>> --
>>>>>
>>>>> ~ Atin (atinm)
>>>>>
>>>>>
>>>>>
>>>>>
>>>>>
>>>>
>>>>
>>>>
>>>> --
>>>>
>>>> ~ Atin (atinm)
>>>>
>>>>
>>>>
>>>>
>>>>
>>>
>>>
>>>
>>> --
>>>
>>> ~ Atin (atinm)
>>>
>>>
>>>
>>>
>>>
>>
>>
>>
>> --
>>
>> ~ Atin (atinm)
>>
>>
>>
>>
>>
>
>
>
> --
>
> ~ Atin (atinm)
>
>
>
>
>
--
~ Atin (atinm)
-------------- next part --------------
An HTML attachment was scrubbed...
URL:
<http://www.gluster.org/pipermail/gluster-users/attachments/20161115/f75c9fac/attachment-0001.html>