graphite is intermittently failing

I configured graphite/opentsd integration. I've build the trees on opentsdb and had graphite use opentsdb data.

It is intermittely working, but sometimes is it failing. When it fails, these are the errors from apache errors:

[Tue Nov 04 12:08:27 2014] [error] Internal Server Error: /metrics/find/
[Tue Nov 04 12:08:27 2014] [error] Traceback (most recent call last):
[Tue Nov 04 12:08:27 2014] [error] File "/usr/local/lib64/python2.6/site-packages/django/core/handlers/base.py", line 112, in get_response
[Tue Nov 04 12:08:27 2014] [error] response = wrapped_callback(request, *callback_args, **callback_kwargs)
[Tue Nov 04 12:08:27 2014] [error] File "/opt/graphite/webapp/graphite/metrics/views.py", line 120, in find_view
[Tue Nov 04 12:08:27 2014] [error] matches = list( STORE.find(query, fromTime, untilTime, local=local_only, drilldown=drilldown) )
[Tue Nov 04 12:08:27 2014] [error] File "/opt/graphite/webapp/graphite/storage.py", line 34, in find
[Tue Nov 04 12:08:27 2014] [error] for node in finder.find_nodes(query):
[Tue Nov 04 12:08:27 2014] [error] File "/opt/graphite/webapp/graphite/finders.py", line 56, in find_nodes
[Tue Nov 04 12:08:27 2014] [error] for node in self.fetch_branch(query):
[Tue Nov 04 12:08:27 2014] [error] File "/opt/graphite/webapp/graphite/finders.py", line 265, in fetch_branch
[Tue Nov 04 12:08:27 2014] [error] self.conn.request("GET", "/api/tree/branch?branch=" + query.pattern)
[Tue Nov 04 12:08:27 2014] [error] File "/usr/lib64/python2.6/httplib.py", line 920, in request
[Tue Nov 04 12:08:27 2014] [error] self._send_request(method, url, body, headers)
[Tue Nov 04 12:08:27 2014] [error] File "/usr/lib64/python2.6/httplib.py", line 937, in _send_request
[Tue Nov 04 12:08:27 2014] [error] self.putrequest(method, url, **skips)
[Tue Nov 04 12:08:27 2014] [error] File "/usr/lib64/python2.6/httplib.py", line 824, in putrequest
[Tue Nov 04 12:08:27 2014] [error] raise CannotSendRequest()
[Tue Nov 04 12:08:27 2014] [error] CannotSendRequest

This is the error on the ui when I try to duplicate the same url call:

CannotSendRequest at /metrics/find/
No exception message supplied
Request Method: GET
Request URL: http://10.5.151.236:8090/metrics/find/?_dc=1415131696288&query=*&format=treejson&path=&node=GraphiteTree
Django Version: 1.6.8
Exception Type: CannotSendRequest
Exception Location: /usr/lib64/python2.6/httplib.py in putrequest, line 824
Python Executable: /usr/bin/python
Python Version: 2.6.9

Any ideas what might be happening here?