I am setting up a box to monitor a ceph cluster. My client config seems to be fine, i am able to run all the commands that these scripts are running inside. But seeing the below errors in collectd log. I am using ubuntu 14.04 with collectd 5.4. Please help me with this issue. Thank you!

[2016-02-25 15:27:40] read-function of plugin `python.ceph_pool_plugin' failed. Will suspend it for 240.000 seconds.
[2016-02-25 15:31:40] ceph: failed to get stats :: No JSON object could be decoded :: Traceback (most recent call last):
File "/usr/lib/collectd/plugins/ceph/base.py", line 108, in read_callback
stats = self.get_stats()
File "/usr/lib/collectd/plugins/ceph/ceph_monitor_plugin.py", line 62, in get_stats
json_data = json.loads(output)
File "/usr/lib/python2.7/json/init.py", line 338, in loads
return _default_decoder.decode(s)
File "/usr/lib/python2.7/json/decoder.py", line 366, in decode
obj, end = self.raw_decode(s, idx=_w(s, 0).end())
File "/usr/lib/python2.7/json/decoder.py", line 384, in raw_decode
raise ValueError("No JSON object could be decoded")
ValueError: No JSON object could be decoded

[2016-02-25 15:31:40] Unhandled python exception in read callback: UnboundLocalError: local variable 'stats' referenced before assignment
[2016-02-25 15:31:40] read-function of plugin `python.ceph_monitor_plugin' failed. Will suspend it for 480.000 seconds.
[2016-02-25 15:31:40] ceph: failed to get stats :: No JSON object could be decoded :: Traceback (most recent call last):
File "/usr/lib/collectd/plugins/ceph/base.py", line 108, in read_callback
stats = self.get_stats()
File "/usr/lib/collectd/plugins/ceph/ceph_pool_plugin.py", line 67, in get_stats
json_stats_data = json.loads(stats_output)
File "/usr/lib/python2.7/json/init.py", line 338, in loads
return _default_decoder.decode(s)
File "/usr/lib/python2.7/json/decoder.py", line 366, in decode
obj, end = self.raw_decode(s, idx=_w(s, 0).end())
File "/usr/lib/python2.7/json/decoder.py", line 384, in raw_decode
raise ValueError("No JSON object could be decoded")
ValueError: No JSON object could be decoded