geo-replication goes to FAULTY state due to lower rsync version

Issue

Geo-replication in RHGS is an asynchronous replication of data. It is mainly used for syncing data across data centers. The data from a master volume is replicated to the slave volume in a different data center via geo-replication. Geo-replication depends on rsync for syncing the contents of the master volume to the slave volume.

If the master node rsync version is lower than that of the slave node, then the following error will be seen on the geo-replication slave(s) and the geo-replication status will become FAULTY.

[2017-01-03 16:24:46.913291] E [syncdutils(/export/dv_repo):276:log_raise_exception] <top>: FAIL: 
Traceback (most recent call last):
  File "/usr/libexec/glusterfs/python/syncdaemon/syncdutils.py", line 306, in twrap
    tf(*aa)
  File "/usr/libexec/glusterfs/python/syncdaemon/master.py", line 1530, in syncjob
    po.errfail()
  File "/usr/libexec/glusterfs/python/syncdaemon/resource.py", line 242, in errfail
    self.errlog()
  File "/usr/libexec/glusterfs/python/syncdaemon/resource.py", line 223, in errlog
    if self.elines:
AttributeError: 'Popen' object has no attribute 'elines'
[2017-01-03 16:24:46.915179] I [syncdutils(/export/dv_repo):220:finalize] <top>: exiting.
[2017-01-03 16:24:46.916677] I [repce(agent):92:service_loop] RepceServer: terminating on reaching EOF.
[2017-01-03 16:24:46.917047] I [syncdutils(agent):220:finalize] <top>: exiting.
[2017-01-03 16:24:47.875291] I [monitor(monitor):290:monitor] Monitor: worker(/export/dv_repo) died in startup phase