HTTPError: HTTP Error 504: Gateway Time-out

Traceback (most recent call last):
  File "/disk2/worker/openkim-pipeline/pipeline/compute.py", line 437, in run
    self.execute_in_place()
  File "/disk2/worker/openkim-pipeline/pipeline/compute.py", line 221, in execute_in_place
    with self.runner_temp.processed_infile(self.subject) as kim_stdin_file, \
  File "/disk2/worker/openkim-pipeline/pipeline/kimobjects.py", line 371, in processed_infile
    template.process(self.infile_path,subject,self)
  File "/disk2/worker/openkim-pipeline/pipeline/template.py", line 118, in process
    output = template.render(**extrainfo)
  File "/disk2/worker/openkim-pipeline/venv/local/lib/python2.7/site-packages/jinja2/environment.py", line 1008, in render
    return self.environment.handle_exception(exc_info, True)
  File "/disk2/worker/openkim-pipeline/venv/local/lib/python2.7/site-packages/jinja2/environment.py", line 780, in handle_exception
    reraise(exc_type, exc_value, tb)
  File "/tmp/SurfaceTest_bcc_Nb_runningTE_965787469599_002-and-MO_218026715338_001-1508889750__TE_965787469599_002/pipeline.stdin.tpl", line 6, in top-level template code
    @<query({"project":["a.si-value"],"sort":"_id","fields":{"a.si-value":1,"_id":0},"database":"data","limit":1,"query":{"meta.runner.kimcode":{"$regex":"LatticeConstantCubicEnergy_bcc_Nb__TE_[0-9]{12}"},"meta.subject.kimcode":MODELNAME,"property-id":{"$regex":"property/structure-cubic-crystal-npt"},"short-name.source-value":"bcc"}})>@
  File "/disk2/worker/openkim-pipeline/pipeline/kimquery.py", line 200, in query_mongo
    answer = open_url(url, data, header, use_SSL)
  File "/disk2/worker/openkim-pipeline/pipeline/kimquery.py", line 26, in open_url
    response = urllib2.urlopen(request, timeout=timeout)
  File "/usr/lib/python2.7/urllib2.py", line 154, in urlopen
    return opener.open(url, data, timeout)
  File "/usr/lib/python2.7/urllib2.py", line 435, in open
    response = meth(req, response)
  File "/usr/lib/python2.7/urllib2.py", line 548, in http_response
    'http', request, response, code, msg, hdrs)
  File "/usr/lib/python2.7/urllib2.py", line 473, in error
    return self._call_chain(*args)
  File "/usr/lib/python2.7/urllib2.py", line 407, in _call_chain
    result = func(*args)
  File "/usr/lib/python2.7/urllib2.py", line 556, in http_error_default
    raise HTTPError(req.get_full_url(), code, msg, hdrs, fp)
HTTPError: HTTP Error 504: Gateway Time-out

output/pipeline.stdout:
-----------------------

output/pipeline.stderr:
-----------------------

output/kim.log:
---------------