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

On Wed, Aug 24, 2016 at 11:25 AM, Ashesh Vashi <
ashesh(dot)vashi(at)enterprisedb(dot)com> wrote:

> Hi Team,
>
> On Sun, Aug 21, 2016 at 3:55 PM, Ashesh Vashi <
> ashesh(dot)vashi(at)enterprisedb(dot)com> wrote:
>
>> On Aug 21, 2016 15:08, "Dave Page" <dpage(at)pgadmin(dot)org> wrote:
>> >
>> > Yeah, but shouldn't it be caught and handled, with a suitable retry
>> yes/no in the UI?
>> And, that realised me, I missed one case, on which I am already working.
>>
> Please find the updated patches.
>
Thanks - Murtuza for point out the issue.

The patches were not generated from the latest changes.
Please find the updated patches.

--

Thanks & Regards,

Ashesh Vashi
EnterpriseDB INDIA: Enterprise PostgreSQL Company
<http://www.enterprisedb.com/>

*http://www.linkedin.com/in/asheshvashi*
<http://www.linkedin.com/in/asheshvashi>

>
> --
>
> Thanks & Regards,
>
> Ashesh Vashi
> EnterpriseDB INDIA: Enterprise PostgreSQL Company
> <http://www.enterprisedb.com/>
>
>
> *http://www.linkedin.com/in/asheshvashi*
> <http://www.linkedin.com/in/asheshvashi>
>
>> --
>> Thanks & Regards,
>>
>> Ashesh Vashi
>> >
>> >
>> > --
>> > 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
>> >>
>> >>
>>
>>
>