A little more information on this, which makes it more puzzling:
1) The split-brain message is strange because there are only two server
nodes and 1 client node which has mounted the volume via NFS on a
floating IP. This was done to guarantee that only one node gets written
to at any point in time, so there is zero chance that two nodes were
updated simultaneously.
2) I re-ran the cpio command to put a file tree on the gluster volume,
then made a tar of the file tree. The tree was not being written to by
anyone, and yet every 5 to 10 files tar would report "file changed as I
read it." At first I thought there was some sort of healing operation
going on, but since I was only writing to one node at a time, then
making the backup, I don't see how this was possible.
I've checked the network, resources, etc., and there are no issues
there, no packet loss, all machines share the same time via NTP, etc.
The OS is SL 6.1.
So this is all very strange behavior.
sean
On 06/16/2012 01:48 PM, Sean Fulton 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
[email protected]
http://gluster.org/cgi-bin/mailman/listinfo/gluster-users
