Re: PATCH/s: RM#1387 - Bad handling of missing connection database server

Yeah, but shouldn't it be caught and handled, with a suitable retry yes/no in the UI?

--
Dave Page
Blog: http://pgsnake.blogspot.com
Twitter: @pgsnake

EnterpriseDB UK:http://www.enterprisedb.com
The Enterprise PostgreSQL Company

> On 20 Aug 2016, at 12:03, Ashesh Vashi <ashesh(dot)vashi(at)enterprisedb(dot)com> wrote:
>
>> On Fri, Aug 19, 2016 at 9:32 PM, Dave Page <dpage(at)pgadmin(dot)org> wrote:
>
>> Hi
>>
>> Can you re-base please? The nodes patch no longer applies.
>>
>> Ignoring that conflict though, the first test I did was to restart the app server when connected to a database. I then (after it restarted) to open the Schemas node in that database; nothing happened at all in the client, but on the server I saw:
> This exception suggests that - pgAdmin 4 was not able to establish the connection again during restarting it.
>
> --
> Thanks & Regards,
>
> Ashesh Vashi
> EnterpriseDB INDIA: Enterprise PostgreSQL Company
>
> http://www.linkedin.com/in/asheshvashi
>>
>> 2016-08-19 16:59:16,321: INFO werkzeug: 127.0.0.1 - - [19/Aug/2016 16:59:16] "GET /browser/schema/nodes/1/1/219759/ HTTP/1.1" 500 -
>> Traceback (most recent call last):
>> File "/Users/dpage/.virtualenvs/pgadmin4/lib/python2.7/site-packages/flask/app.py", line 2000, in __call__
>> return self.wsgi_app(environ, start_response)
>> File "/Users/dpage/.virtualenvs/pgadmin4/lib/python2.7/site-packages/flask/app.py", line 1991, in wsgi_app
>> response = self.make_response(self.handle_exception(e))
>> File "/Users/dpage/.virtualenvs/pgadmin4/lib/python2.7/site-packages/flask/app.py", line 1567, in handle_exception
>> reraise(exc_type, exc_value, tb)
>> File "/Users/dpage/.virtualenvs/pgadmin4/lib/python2.7/site-packages/flask/app.py", line 1988, in wsgi_app
>> response = self.full_dispatch_request()
>> File "/Users/dpage/.virtualenvs/pgadmin4/lib/python2.7/site-packages/flask/app.py", line 1641, in full_dispatch_request
>> rv = self.handle_user_exception(e)
>> File "/Users/dpage/.virtualenvs/pgadmin4/lib/python2.7/site-packages/flask/app.py", line 1544, in handle_user_exception
>> reraise(exc_type, exc_value, tb)
>> File "/Users/dpage/.virtualenvs/pgadmin4/lib/python2.7/site-packages/flask/app.py", line 1639, in full_dispatch_request
>> rv = self.dispatch_request()
>> File "/Users/dpage/.virtualenvs/pgadmin4/lib/python2.7/site-packages/flask/app.py", line 1625, in dispatch_request
>> return self.view_functions[rule.endpoint](**req.view_args)
>> File "/Users/dpage/.virtualenvs/pgadmin4/lib/python2.7/site-packages/flask/views.py", line 84, in view
>> return self.dispatch_request(*args, **kwargs)
>> File "/Users/dpage/git/pgadmin4/web/pgadmin/browser/utils.py", line 235, in dispatch_request
>> return method(*args, **kwargs)
>> File "/Users/dpage/git/pgadmin4/web/pgadmin/browser/server_groups/servers/databases/schemas/__init__.py", line 129, in wrap
>> self.conn = self.manager.connection(did=kwargs['did'])
>> File "/Users/dpage/git/pgadmin4/web/pgadmin/utils/driver/psycopg2/__init__.py", line 1330, in connection
>> raise Exception(msg_active_conn)
>>
>> I realise it could well be caused by the conflict when applying the nodes patch, but just in case it's not... :-)
>>
>>> On Fri, Aug 19, 2016 at 12:25 PM, Ashesh Vashi <ashesh(dot)vashi(at)enterprisedb(dot)com> wrote:
>>> Hi Dave/Team,
>>>
>>> I have attached three patches targeting specific area of work.
>>>
>>> -> backend_connection_status_management
>>> * Takes care of the connection status in the psycopg2 driver. And, when the connection is lost, it throws a exception with 503 http status message, and connection lost information in it.
>>> * Contains a change to allow to the flask application to propagate the exceptions even in the release mode.
>>> * Modification for utilising the existing password (while reconnection, if not disconnected explicitly).
>>> * Introduced a new ajax response message 'service_unavailable' (http status code: 503), which suggests temporary service unavailable.
>>>
>>> -> manage_client_connect_lost
>>> * It handles the connection lost for different operations at client (browser) side.
>>> * Using the events to handle this situation.
>>>
>>> -> remove_connection_status_check
>>> * We're currently return precondition_required (HTTP status code: 428) for the same, but - there is no consistent message/information available to identify it reliably as the server connection lost error (client side changes takes care of this situation, but - this patch is recommended for the whole change to work properly). This patch removes the connection status check from the individual nodes.
>>>
>>>
>>> TODO:
>>> * Browser tree - node expansion
>>> - When there is an error occurred during expanding the aci-tree node, it does not let the client handle the issue based on the status code, and error message, as it does not expose/share the error details with us. We will have to hack the aci-tree for the same.
>>>
>>> * Query Editor
>>> - Slick grid changes are in progress, hence - I did not touch the code for it, as it will lead to rework for either one of us (me, or Murtuza). I will take care of it as soon as the slick grid changes will be committed.
>>>
>>> --
>>> Thanks & Regards,
>>>
>>> Ashesh Vashi
>>> EnterpriseDB INDIA: Enterprise PostgreSQL Company
>>>
>>> http://www.linkedin.com/in/asheshvashi
>>
>>
>>
>> --
>> Dave Page
>> Blog: http://pgsnake.blogspot.com
>> Twitter: @pgsnake
>>
>> EnterpriseDB UK: http://www.enterprisedb.com
>> The Enterprise PostgreSQL Company
>