Connection pool is exhausted

[alanhdu]

Presumably due to how expensive the predict page is.

Traceback (most recent call last):
  File "/root/.local/share/virtualenvs/density-7DeN0QYC/lib/python3.6/site-packages/gunicorn/workers/sync.py", line 135, in handle
    self.handle_request(listener, req, client, addr)
  File "/root/.local/share/virtualenvs/density-7DeN0QYC/lib/python3.6/site-packages/gunicorn/workers/sync.py", line 176, in handle_request
    respiter = self.wsgi(environ, resp.start_response)
  File "/root/.local/share/virtualenvs/density-7DeN0QYC/lib/python3.6/site-packages/flask/app.py", line 1997, in __call__
    return self.wsgi_app(environ, start_response)
  File "/root/.local/share/virtualenvs/density-7DeN0QYC/lib/python3.6/site-packages/flask/app.py", line 1985, in wsgi_app
    response = self.handle_exception(e)
  File "/root/.local/share/virtualenvs/density-7DeN0QYC/lib/python3.6/site-packages/flask/app.py", line 1540, in handle_exception
    reraise(exc_type, exc_value, tb)
  File "/root/.local/share/virtualenvs/density-7DeN0QYC/lib/python3.6/site-packages/flask/_compat.py", line 33, in reraise
    raise value
  File "/root/.local/share/virtualenvs/density-7DeN0QYC/lib/python3.6/site-packages/flask/app.py", line 1982, in wsgi_app
    response = self.full_dispatch_request()
  File "/root/.local/share/virtualenvs/density-7DeN0QYC/lib/python3.6/site-packages/flask/app.py", line 1614, in full_dispatch_request
    rv = self.handle_user_exception(e)
  File "/root/.local/share/virtualenvs/density-7DeN0QYC/lib/python3.6/site-packages/flask/app.py", line 1517, in handle_user_exception
    reraise(exc_type, exc_value, tb)
  File "/root/.local/share/virtualenvs/density-7DeN0QYC/lib/python3.6/site-packages/flask/_compat.py", line 33, in reraise
    raise value
  File "/root/.local/share/virtualenvs/density-7DeN0QYC/lib/python3.6/site-packages/flask/app.py", line 1610, in full_dispatch_request
    rv = self.preprocess_request()
  File "/root/.local/share/virtualenvs/density-7DeN0QYC/lib/python3.6/site-packages/flask/app.py", line 1831, in preprocess_request
    rv = func()
  File "/density/density/__init__.py", line 40, in get_connections
    g.pg_conn = pg_pool.getconn()
  File "/root/.local/share/virtualenvs/density-7DeN0QYC/lib/python3.6/site-packages/psycopg2/pool.py", line 91, in _getconn
    raise PoolError("connection pool exhausted")
psycopg2.pool.PoolError: connection pool exhausted

[ignacio-ramirez-piriz]

Seems to be working now. The problem seemed to be at librarytimes.py. I added caching (for three hour periods) for predictions so it shouldn't be that expensive