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

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.

--
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
>>
>>