[Gluster-users] Not real confident in 3.3

Sean Fulton sean at gcnpublishing.com
Sun Jun 17 12:21:13 UTC 2012


This was a Linux-HA cluster with a floating IP that the clients would 
mount off of whichever server is active. So I set up a two-node 
replicated cluster, which the floating IP and heartbeat, and the client 
mounted the drive over the floating IP. I'm using the NFS server built 
into gluster. So rpcbind and nfslock are running on the server, but not 
nfs. The client writes to the one server with the floating IP, and 
gluster takes care of keeping the volume in sync between the two 
servers. I thought that was the way to do it.



sean


On 06/16/2012 07:17 PM, Frank Sonntag wrote:
> Hi Sean,
>
> What kernel are you using? I had similar trouble (hanging processes) with a installed Centos 6.2 system. All the 2.6.32 kernels available in the centos repository gave me these hangs and only after upgrading to v3 of there kernel (using the EL repositories) could I fix the problem. I even had these hangs when using just kernel based NFS, so my problem could be different of course.
> gluster 3.2.6 now works fine for me (using one replicated and one distributed volume anyway. I still have trouble with a getting nufa to work).
> BTW I just realized you are using the NFS to mount a replicated volume on the client. Is that right? I don't think his will work since the gluster client is the component doing the replication (i.e. sending files to both servers).
>
> Frank
>
>
>
>
>
> On 17/06/2012, at 9:12 AM, Sean Fulton wrote:
>
>> Let me re-iterate, I really, really want to see Gluster work for our environment. I am hopeful this is something I did or something that can be easily fixed.
>>
>> Yes, there was an error on the client server:
>>
>> [586898.273283] INFO: task flush-0:45:633954 blocked for more than 120 seconds.
>> [586898.273290] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
>> [586898.273295] flush-0:45    D ffff8806037592d0     0 633954      2    0 0x00000000
>> [586898.273304]  ffff88000d1ebbe0 0000000000000046 ffff88000d1ebd6c 0000000000000000
>> [586898.273312]  ffff88000d1ebce0 ffffffff81054444 ffff88000d1ebc80 ffff88000d1ebbf0
>> [586898.273319]  ffff8806050ac5f8 ffff880603759888 ffff88000d1ebfd8 ffff88000d1ebfd8
>> [586898.273326] Call Trace:
>> [586898.273335]  [<ffffffff81054444>] ? find_busiest_group+0x244/0xb20
>> [586898.273343]  [<ffffffff811ab050>] ? inode_wait+0x0/0x20
>> [586898.273349]  [<ffffffff811ab05e>] inode_wait+0xe/0x20
>> [586898.273357]  [<ffffffff814e752f>] __wait_on_bit+0x5f/0x90
>> [586898.273365]  [<ffffffff811bbd6c>] ? writeback_sb_inodes+0x13c/0x210
>> [586898.273370]  [<ffffffff811bab28>] inode_wait_for_writeback+0x98/0xc0
>> [586898.273377]  [<ffffffff81095550>] ? wake_bit_function+0x0/0x50
>> [586898.273382]  [<ffffffff811bc1f8>] wb_writeback+0x218/0x420
>> [586898.273389]  [<ffffffff814e637e>] ? thread_return+0x4e/0x7d0
>> [586898.273394]  [<ffffffff811bc5a9>] wb_do_writeback+0x1a9/0x250
>> [586898.273402]  [<ffffffff8107e2e0>] ? process_timeout+0x0/0x10
>> [586898.273407]  [<ffffffff811bc6b3>] bdi_writeback_task+0x63/0x1b0
>> [586898.273412]  [<ffffffff810953e7>] ? bit_waitqueue+0x17/0xc0
>> [586898.273419]  [<ffffffff8114ce80>] ? bdi_start_fn+0x0/0x100
>> [586898.273424]  [<ffffffff8114cf06>] bdi_start_fn+0x86/0x100
>> [586898.273429]  [<ffffffff8114ce80>] ? bdi_start_fn+0x0/0x100
>> [586898.273434]  [<ffffffff81094f36>] kthread+0x96/0xa0
>> [586898.273440]  [<ffffffff8100c20a>] child_rip+0xa/0x20
>> [586898.273445]  [<ffffffff81094ea0>] ? kthread+0x0/0xa0
>> [586898.273450]  [<ffffffff8100c200>] ? child_rip+0x0/0x20
>> [root at server-10 ~]#
>>
>>
>>
>> Here are the file sizes. Secure was big, but was hung for quite a long time:
>>
>> -rw------- 1 root root         0 Dec 20 10:17 boot.log
>> -rw------- 1 root utmp 281079168 Jun 15 21:53 btmp
>> -rw------- 1 root root    337661 Jun 16 16:36 cron
>> -rw-r--r-- 1 root root         0 Jun  9 18:33 dmesg
>> -rw-r--r-- 1 root root         0 Jun  9 16:19 dmesg.old
>> -rw-r--r-- 1 root root     98585 Dec 21 14:32 dracut.log
>> drwxr-xr-x 5 root root      4096 Dec 21 16:53 glusterfs
>> drwx------ 2 root root      4096 Mar  1 16:11 httpd
>> -rw-r--r-- 1 root root    146000 Jun 16 13:36 lastlog
>> drwxr-xr-x 2 root root      4096 Dec 20 10:35 mail
>> -rw------- 1 root root   1072902 Jun  9 18:33 maillog
>> -rw------- 1 root root     50638 Jun 16 12:13 messages
>> drwxr-xr-x 2 root root      4096 Dec 30 16:14 nginx
>> drwx------ 3 root root      4096 Dec 20 10:35 samba
>> -rw------- 1 root root 222214339 Jun 16 13:37 secure
>> -rw------- 1 root root         0 Sep 13  2011 spooler
>> -rw------- 1 root root         0 Sep 13  2011 tallylog
>> -rw-rw-r-- 1 root utmp    114432 Jun 16 13:37 wtmp
>> -rw------- 1 root root      7015 Jun 16 12:13 yum.log
>>
>> On 06/16/2012 05:04 PM, Anand Avati wrote:
>>> Was there anything in dmesg on the servers? If you are able to reproduce the hang, can you get the output of 'gluster volume status <name> callpool' and 'gluster volume status <name> nfs callpool' ?
>>>
>>> How big is the 'log/secure' file? Is it so large the the client was just busy writing it for a very long time? Are there any signs of disconnections or ping tmeouts in the logs?
>>>
>>> Avati
>>>
>>> On Sat, Jun 16, 2012 at 10:48 AM, Sean Fulton <sean at gcnpublishing.com> wrote:
>>> I do not mean to be argumentative, but I have to admit a little frustration with Gluster. I know an enormous emount of effort has gone into this product, and I just can't believe that with all the effort behind it and so many people using it, it could be so fragile.
>>>
>>> So here goes. Perhaps someone here can point to the error of my ways. I really want this to work because it would be ideal for our environment, but ...
>>>
>>> Please note that all of the nodes below are OpenVZ nodes with nfs/nfsd/fuse modules loaded on the hosts.
>>>
>>> After spending months trying to get 3.2.5 and 3.2.6 working in a production environment, I gave up on Gluster and went with a Linux-HA/NFS cluster which just works. The problems I had with gluster were strange lock-ups, split brains, and too many instances where the whole cluster was off-line until I reloaded the data.
>>>
>>> So wiith the release of 3.3, I decided to give it another try. I created one relicated volume on my two NFS servers.
>>>
>>> I then mounted the volume on a client as follows:
>>> 10.10.10.7:/pub2    /pub2     nfs rw,noacl,noatime,nodiratime,soft,proto=tcp,vers=3,defaults 0 0
>>>
>>> I threw some data at it (find / -mount -print | cpio -pvdum /pub2/test)
>>>
>>> Within 10 seconds it locked up solid. No error messages on any of the servers, the client was unresponsive and load on the client was 15+. I restarted glusterd on both of my NFS servers, and the client remained locked. Finally I killed the cpio process on the client. When I started another cpio, it runs further than before, but now the logs on my NFS/Gluster server say:
>>>
>>> [2012-06-16 13:37:35.242754] I [afr-self-heal-common.c:1318:afr_sh_missing_entries_lookup_done] 0-pub2-replicate-0: No sources for dir of <gfid:4a787ad7-ab91-46ef-9b31-715e49f5f818>/log/secure, in missing entry self-heal, continuing with the rest of the self-heals
>>> [2012-06-16 13:37:35.243315] I [afr-self-heal-common.c:994:afr_sh_missing_entries_done] 0-pub2-replicate-0: split brain found, aborting selfheal of <gfid:4a787ad7-ab91-46ef-9b31-715e49f5f818>/log/secure
>>> [2012-06-16 13:37:35.243350] E [afr-self-heal-common.c:2156:afr_self_heal_completion_cbk] 0-pub2-replicate-0: background  data gfid self-heal failed on <gfid:4a787ad7-ab91-46ef-9b31-715e49f5f818>/log/secure
>>>
>>>
>>> This still seems to be an INCREDIBLY fragile system. Why would it lock solid while copying a large file? Why no errors in the logs?
>>>
>>> I am the only one seeing this kind of behavior?
>>>
>>> sean
>>>
>>>
>>>
>>>
>>>
>>> -- 
>>> Sean Fulton
>>> GCN Publishing, Inc.
>>> Internet Design, Development and Consulting For Today's Media Companies
>>> http://www.gcnpublishing.com
>>> (203) 665-6211, x203
>>>
>>> _______________________________________________
>>> Gluster-users mailing list
>>> Gluster-users at gluster.org
>>> http://gluster.org/cgi-bin/mailman/listinfo/gluster-users
>>>
>> -- 
>> Sean Fulton
>> GCN Publishing, Inc.
>> Internet Design, Development and Consulting For Today's Media Companies
>>
>> http://www.gcnpublishing.com
>>
>> (203) 665-6211, x203
>>
>>
>>
>>
>> _______________________________________________
>> Gluster-users mailing list
>> Gluster-users at gluster.org
>> http://gluster.org/cgi-bin/mailman/listinfo/gluster-users
>

-- 
Sean Fulton
GCN Publishing, Inc.
Internet Design, Development and Consulting For Today's Media Companies
http://www.gcnpublishing.com
(203) 665-6211, x203






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