Bug 1009265

Description of problem:
When all geo-replication instances running on a node uses same config file (multiple bricks on the same server); If one instance goes into xsync mode and write change_detector - xsync in config file and after that on re start (because of any reason) other instances would fall back to xsync mode.


Version-Release number of selected component (if applicable):
3.4.0.33rhs-1.el6rhs.x86_64

How reproducible:
always

Steps to Reproduce:
1.  create and start dist-rep volume and mount it.Start creating data on master volume from mount point. 
--> Make sure that master volume has more than one brick on same RHSS

mount point:-
mount | grep remove_xsync
10.70.35.179:/remove_xsync on /mnt/remove_xsync type fuse.glusterfs (rw,default_permissions,allow_other,max_read=131072)
10.70.35.179:/remove_xsync on /mnt/remove_xsync_nfs type nfs (rw,addr=10.70.35.179)


2, create and start geo rep session between master and slave volume.
[root@old5 ~]# gluster volume geo remove_xsync status
NODE                           MASTER           SLAVE                                HEALTH    UPTIME                
-----------------------------------------------------------------------------------------------------------------
old5.lab.eng.blr.redhat.com    remove_xsync    ssh://10.70.37.195::remove_xsync    Stable    4 days 07:12:33       
old6.lab.eng.blr.redhat.com    remove_xsync    ssh://10.70.37.195::remove_xsync    Stable    4 days 23:52:43 

-> one RHSS has 3 bricks so all 3 geo-replication instances on that node will share same config file

3. remove brick(s) from master volume with start option.

--> gluster volume remove-brick remove_xsync 10.70.35.179:/rhs/brick3/x3 10.70.35.235:/rhs/brick3/x3 start

4. once remove-brick is completed perform commit operation
 gluster volume remove-brick remove_xsync 10.70.35.179:/rhs/brick3/x3 10.70.35.235:/rhs/brick3/x3 status
 gluster volume remove-brick remove_xsync 10.70.35.179:/rhs/brick3/x3 10.70.35.235:/rhs/brick3/x3 commit

[root@old5 ~]# gluster v info remove_change
 
Volume Name: remove_change
Type: Distributed-Replicate
Volume ID: eb500199-37d4-4cb9-96ed-ae5bc1bf2498
Status: Started
Number of Bricks: 2 x 2 = 4
Transport-type: tcp
Bricks:
Brick1: 10.70.35.179:/rhs/brick3/c1
Brick2: 10.70.35.235:/rhs/brick3/c1
Brick3: 10.70.35.179:/rhs/brick3/c2
Brick4: 10.70.35.235:/rhs/brick3/c2
Options Reconfigured:
changelog.changelog: on
geo-replication.ignore-pid-check: on
geo-replication.indexing: on

5.on remove-brick commit operation, that brick process get killed so geo-replication instance for that brick fall back to xsync and same was written in config file. 

On getting ' ECONNABORTED' other instances on same RHSS were restarted and as config file has change_detector - xsync, all other instances fall back to xsync.

[root@old5 ~]# gluster volume geo remove_xsync 10.70.37.195::remove_xsync config | grep change_detector
change_detector: xsync

log snippet:-
 less /var/log/glusterfs/geo-replication/remove_xsync/ssh%3A%2F%2Froot%4010.70.37.195%3Agluster%3A%2F%2F127.0.0.1%3Aremove_xsync.log 

[2013-09-16 14:56:33.944725] I [master(/rhs/brick2/x3):587:fallback_xsync] _GMaster: falling back to xsync mode
[2013-09-16 14:56:48.72854] I [syncdutils(/rhs/brick2/x3):159:finalize] <top>: exiting.
[2013-09-16 14:56:50.587552] E [syncdutils(/rhs/brick2/x1):201:log_raise_exception] <top>: glusterfs session went down [ECONNABORTED]
[2013-09-16 14:56:52.982089] I [syncdutils(/rhs/brick2/x1):159:finalize] <top>: exiting.
[2013-09-16 14:56:51.429940] E [syncdutils(/rhs/brick2/x2):201:log_raise_exception] <top>: glusterfs session went down [ECONNABORTED]
[2013-09-16 14:56:53.641541] I [syncdutils(/rhs/brick2/x2):159:finalize] <top>: exiting.
[2013-09-16 14:56:56.116944] I [monitor(monitor):81:set_state] Monitor: new state: faulty
[2013-09-16 14:57:12.589235] I [monitor(monitor):129:monitor] Monitor: ------------------------------------------------------------
[2013-09-16 14:57:12.786187] I [monitor(monitor):130:monitor] Monitor: starting gsyncd worker
[2013-09-16 14:57:12.730447] I [monitor(monitor):129:monitor] Monitor: ------------------------------------------------------------
[2013-09-16 14:57:12.844243] I [monitor(monitor):130:monitor] Monitor: starting gsyncd worker
[2013-09-16 14:57:13.646564] I [monitor(monitor):129:monitor] Monitor: ------------------------------------------------------------
[2013-09-16 14:57:13.647228] I [monitor(monitor):130:monitor] Monitor: starting gsyncd worker
[2013-09-16 14:57:14.677306] I [gsyncd(/rhs/brick2/x2):503:main_i] <top>: syncing: gluster://localhost:remove_xsync -> ssh://root
.37.195:gluster://localhost:remove_xsync
[2013-09-16 14:57:14.682374] I [gsyncd(/rhs/brick2/x3):503:main_i] <top>: syncing: gluster://localhost:remove_xsync -> ssh://root
.37.98:gluster://localhost:remove_xsync
[2013-09-16 14:57:14.684375] I [gsyncd(/rhs/brick2/x1):503:main_i] <top>: syncing: gluster://localhost:remove_xsync -> ssh://root
.37.98:gluster://localhost:remove_xsync
[2013-09-16 14:57:21.670073] I [master(/rhs/brick2/x2):57:gmaster_builder] <top>: setting up xsync change detection mode
[2013-09-16 14:57:21.676136] I [master(/rhs/brick2/x2):57:gmaster_builder] <top>: setting up xsync change detection mode
[2013-09-16 14:57:21.688627] I [master(/rhs/brick2/x2):816:register] _GMaster: xsync temp directory: /var/run/gluster/remove_xsync/ssh%3A%2F%2Froot%4010.70.37.195%3Agluster%3A%2F%2F127.0.0.1%3Aremove_xsync/9b86668c9bd1c074e1e2720fc5005e44/xsync
[2013-09-16 14:57:21.688901] I [master(/rhs/brick2/x2):816:register] _GMaster: xsync temp directory: /var/run/gluster/remove_xsync/ssh%3A%2F%2Froot%4010.70.37.195%3Agluster%3A%2F%2F127.0.0.1%3Aremove_xsync/9b86668c9bd1c074e1e2720fc5005e44/xsync
[2013-09-16 14:57:22.300641] I [master(/rhs/brick2/x3):57:gmaster_builder] <top>: setting up xsync change detection mode
[2013-09-16 14:57:22.320192] I [master(/rhs/brick2/x1):57:gmaster_builder] <top>: setting up xsync change detection mode
[2013-09-16 14:57:22.320787] I [master(/rhs/brick2/x3):57:gmaster_builder] <top>: setting up xsync change detection mode
[2013-09-16 14:57:22.323508] I [master(/rhs/brick2/x1):57:gmaster_builder] <top>: setting up xsync change detection mode

Actual results:
as all instances are using same config file, other instances also started using xsync mode instead of change log.