Hue 4.6 - cdh 7.1.6.0 Error 500 when connecting to Hue

[#1]

Getting error 500 when connecting - Hue installed from Cloudera Manager. Here are Hue logs:
Traceback (most recent call last): File "/opt/cloudera/parcels/CDH-7.1.6-1.cdh7.1.6.p0.10506313/lib/hue/desktop/core/src/desktop/lib/wsgiserver.py", line 1228, in communicate req.respond() File "/opt/cloudera/parcels/CDH-7.1.6-1.cdh7.1.6.p0.10506313/lib/hue/desktop/core/src/desktop/lib/wsgiserver.py", line 589, in respond self._respond() File "/opt/cloudera/parcels/CDH-7.1.6-1.cdh7.1.6.p0.10506313/lib/hue/desktop/core/src/desktop/lib/wsgiserver.py", line 601, in _respond response = self.wsgi_app(self.environ, self.start_response) File "/opt/cloudera/parcels/CDH-7.1.6-1.cdh7.1.6.p0.10506313/lib/hue/build/env/lib/python2.7/site-packages/Django-1.11.29-py2.7.egg/django/core/handlers/wsgi.py", line 157, in __call__ response = self.get_response(request) File "/opt/cloudera/parcels/CDH-7.1.6-1.cdh7.1.6.p0.10506313/lib/hue/build/env/lib/python2.7/site-packages/Django-1.11.29-py2.7.egg/django/core/handlers/base.py", line 124, in get_response response = self._middleware_chain(request) File "/opt/cloudera/parcels/CDH-7.1.6-1.cdh7.1.6.p0.10506313/lib/hue/build/env/lib/python2.7/site-packages/Django-1.11.29-py2.7.egg/django/core/handlers/exception.py", line 43, in inner response = response_for_exception(request, exc) File "/opt/cloudera/parcels/CDH-7.1.6-1.cdh7.1.6.p0.10506313/lib/hue/build/env/lib/python2.7/site-packages/Django-1.11.29-py2.7.egg/django/core/handlers/exception.py", line 93, in response_for_exception response = handle_uncaught_exception(request, get_resolver(get_urlconf()), sys.exc_info()) File "/opt/cloudera/parcels/CDH-7.1.6-1.cdh7.1.6.p0.10506313/lib/hue/build/env/lib/python2.7/site-packages/Django-1.11.29-py2.7.egg/django/core/handlers/exception.py", line 143, in handle_uncaught_exception return callback(request, **param_dict) File "/opt/cloudera/parcels/CDH-7.1.6-1.cdh7.1.6.p0.10506313/lib/hue/desktop/core/src/desktop/views.py", line 415, in serve_500_error return render("500.mako", request, {'traceback': traceback.extract_tb(exc_info[2])}) File "/opt/cloudera/parcels/CDH-7.1.6-1.cdh7.1.6.p0.10506313/lib/hue/desktop/core/src/desktop/lib/django_util.py", line 241, in render **kwargs File "/opt/cloudera/parcels/CDH-7.1.6-1.cdh7.1.6.p0.10506313/lib/hue/desktop/core/src/desktop/lib/django_util.py", line 154, in _render_to_response return django_mako.render_to_response(template, *args, **kwargs) File "/opt/cloudera/parcels/CDH-7.1.6-1.cdh7.1.6.p0.10506313/lib/hue/desktop/core/src/desktop/lib/django_mako.py", line 127, in render_to_response return HttpResponse(render_to_string(template_name, data_dictionary), **kwargs) File "/opt/cloudera/parcels/CDH-7.1.6-1.cdh7.1.6.p0.10506313/lib/hue/desktop/core/src/desktop/lib/django_mako.py", line 116, in render_to_string_normal result = template.render(**data_dict) File "/opt/cloudera/parcels/CDH-7.1.6-1.cdh7.1.6.p0.10506313/lib/hue/build/env/lib/python2.7/site-packages/Mako-1.0.7-py2.7.egg/mako/template.py", line 462, in render return runtime._render(self, self.callable_, args, data) File "/opt/cloudera/parcels/CDH-7.1.6-1.cdh7.1.6.p0.10506313/lib/hue/build/env/lib/python2.7/site-packages/Mako-1.0.7-py2.7.egg/mako/runtime.py", line 838, in _render **_kwargs_for_callable(callable_, data)) File "/opt/cloudera/parcels/CDH-7.1.6-1.cdh7.1.6.p0.10506313/lib/hue/build/env/lib/python2.7/site-packages/Mako-1.0.7-py2.7.egg/mako/runtime.py", line 873, in _render_context _exec_template(inherit, lclcontext, args=args, kwargs=kwargs) File "/opt/cloudera/parcels/CDH-7.1.6-1.cdh7.1.6.p0.10506313/lib/hue/build/env/lib/python2.7/site-packages/Mako-1.0.7-py2.7.egg/mako/runtime.py", line 899, in _exec_template callable_(context, *args, **kwargs) File "/tmp/tmpNphhZ_/desktop/500.mako.py", line 40, in render_body __M_writer(unicode( commonheader(_('500 - Server error'), "", user, request) )) File "/opt/cloudera/parcels/CDH-7.1.6-1.cdh7.1.6.p0.10506313/lib/hue/desktop/core/src/desktop/views.py", line 469, in commonheader current_app, other_apps, apps_list = _get_apps(user, section) File "/opt/cloudera/parcels/CDH-7.1.6-1.cdh7.1.6.p0.10506313/lib/hue/desktop/core/src/desktop/models.py", line 2136, in _get_apps if user.is_authenticated(): File "/opt/cloudera/parcels/CDH-7.1.6-1.cdh7.1.6.p0.10506313/lib/hue/build/env/lib/python2.7/site-packages/Django-1.11.29-py2.7.egg/django/utils/functional.py", line 238, in inner self._setup() File "/opt/cloudera/parcels/CDH-7.1.6-1.cdh7.1.6.p0.10506313/lib/hue/build/env/lib/python2.7/site-packages/Django-1.11.29-py2.7.egg/django/utils/functional.py", line 386, in _setup self._wrapped = self._setupfunc() File "/opt/cloudera/parcels/CDH-7.1.6-1.cdh7.1.6.p0.10506313/lib/hue/build/env/lib/python2.7/site-packages/Django-1.11.29-py2.7.egg/django/contrib/auth/middleware.py", line 24, in request.user = SimpleLazyObject(lambda: get_user(request)) File "/opt/cloudera/parcels/CDH-7.1.6-1.cdh7.1.6.p0.10506313/lib/hue/build/env/lib/python2.7/site-packages/Django-1.11.29-py2.7.egg/django/contrib/auth/middleware.py", line 12, in get_user request._cached_user = auth.get_user(request) File "/opt/cloudera/parcels/CDH-7.1.6-1.cdh7.1.6.p0.10506313/lib/hue/build/env/lib/python2.7/site-packages/Django-1.11.29-py2.7.egg/django/contrib/auth/__init__.py", line 211, in get_user user_id = _get_user_session_key(request) File "/opt/cloudera/parcels/CDH-7.1.6-1.cdh7.1.6.p0.10506313/lib/hue/build/env/lib/python2.7/site-packages/Django-1.11.29-py2.7.egg/django/contrib/auth/__init__.py", line 61, in _get_user_session_key return get_user_model()._meta.pk.to_python(request.session[SESSION_KEY]) File "/opt/cloudera/parcels/CDH-7.1.6-1.cdh7.1.6.p0.10506313/lib/hue/build/env/lib/python2.7/site-packages/Django-1.11.29-py2.7.egg/django/contrib/sessions/backends/base.py", line 57, in __getitem__ return self._session[key] File "/opt/cloudera/parcels/CDH-7.1.6-1.cdh7.1.6.p0.10506313/lib/hue/build/env/lib/python2.7/site-packages/Django-1.11.29-py2.7.egg/django/contrib/sessions/backends/base.py", line 207, in _get_session self._session_cache = self.load() File "/opt/cloudera/parcels/CDH-7.1.6-1.cdh7.1.6.p0.10506313/lib/hue/build/env/lib/python2.7/site-packages/Django-1.11.29-py2.7.egg/django/contrib/sessions/backends/db.py", line 35, in load expire_date__gt=timezone.now() File "/opt/cloudera/parcels/CDH-7.1.6-1.cdh7.1.6.p0.10506313/lib/hue/build/env/lib/python2.7/site-packages/Django-1.11.29-py2.7.egg/django/db/models/manager.py", line 85, in manager_method return getattr(self.get_queryset(), name)(*args, **kwargs) File "/opt/cloudera/parcels/CDH-7.1.6-1.cdh7.1.6.p0.10506313/lib/hue/build/env/lib/python2.7/site-packages/Django-1.11.29-py2.7.egg/django/db/models/query.py", line 374, in get num = len(clone) File "/opt/cloudera/parcels/CDH-7.1.6-1.cdh7.1.6.p0.10506313/lib/hue/build/env/lib/python2.7/site-packages/Django-1.11.29-py2.7.egg/django/db/models/query.py", line 232, in __len__ self._fetch_all() File "/opt/cloudera/parcels/CDH-7.1.6-1.cdh7.1.6.p0.10506313/lib/hue/build/env/lib/python2.7/site-packages/Django-1.11.29-py2.7.egg/django/db/models/query.py", line 1121, in _fetch_all self._result_cache = list(self._iterable_class(self)) File "/opt/cloudera/parcels/CDH-7.1.6-1.cdh7.1.6.p0.10506313/lib/hue/build/env/lib/python2.7/site-packages/Django-1.11.29-py2.7.egg/django/db/models/query.py", line 53, in __iter__ results = compiler.execute_sql(chunked_fetch=self.chunked_fetch) File "/opt/cloudera/parcels/CDH-7.1.6-1.cdh7.1.6.p0.10506313/lib/hue/build/env/lib/python2.7/site-packages/Django-1.11.29-py2.7.egg/django/db/models/sql/compiler.py", line 887, in execute_sql cursor = self.connection.cursor() File "/opt/cloudera/parcels/CDH-7.1.6-1.cdh7.1.6.p0.10506313/lib/hue/build/env/lib/python2.7/site-packages/Django-1.11.29-py2.7.egg/django/db/backends/base/base.py", line 254, in cursor return self._cursor() File "/opt/cloudera/parcels/CDH-7.1.6-1.cdh7.1.6.p0.10506313/lib/hue/build/env/lib/python2.7/site-packages/Django-1.11.29-py2.7.egg/django/db/backends/base/base.py", line 229, in _cursor self.ensure_connection() File "/opt/cloudera/parcels/CDH-7.1.6-1.cdh7.1.6.p0.10506313/lib/hue/build/env/lib/python2.7/site-packages/Django-1.11.29-py2.7.egg/django/db/backends/base/base.py", line 213, in ensure_connection self.connect() File "/opt/cloudera/parcels/CDH-7.1.6-1.cdh7.1.6.p0.10506313/lib/hue/build/env/lib/python2.7/site-packages/Django-1.11.29-py2.7.egg/django/db/utils.py", line 94, in __exit__ six.reraise(dj_exc_type, dj_exc_value, traceback) File "/opt/cloudera/parcels/CDH-7.1.6-1.cdh7.1.6.p0.10506313/lib/hue/build/env/lib/python2.7/site-packages/Django-1.11.29-py2.7.egg/django/db/backends/base/base.py", line 213, in ensure_connection self.connect() File "/opt/cloudera/parcels/CDH-7.1.6-1.cdh7.1.6.p0.10506313/lib/hue/build/env/lib/python2.7/site-packages/Django-1.11.29-py2.7.egg/django/db/backends/base/base.py", line 189, in connect self.connection = self.get_new_connection(conn_params) File "/opt/cloudera/parcels/CDH-7.1.6-1.cdh7.1.6.p0.10506313/lib/hue/build/env/lib/python2.7/site-packages/Django-1.11.29-py2.7.egg/django/db/backends/postgresql/base.py", line 176, in get_new_connection connection = Database.connect(**conn_params) File "/opt/cloudera/cm-agent/service/hue/psycopg2/__init__.py", line 130, in connect conn = _connect(dsn, connection_factory=connection_factory, **kwasync) OperationalError: FATAL: remaining connection slots are reserved for non-replication superuser connections

[#2 · Accepted solution]

Solved - increasing the number of connection on postgresql - editing postgresql.conf, incrising max_connections number and restart postgresql.