Re: [pgAdmin][RM4818] Unable to handle loss of connection to server

Hi Aditya

Following are the review comments:

- Update the timeout in the comment section from 30 seconds to 10 seconds
in aff1436e3c8c_.py.
- Asking for the database server password even if it is saved. Reproduction
steps:

- Connect to the database server, saved the password.
- Disabled the network. Try to connect to the database server.
- Enable the network, try to connect to the database server.

- No error/spinner visible on GUI when the database server is connected
using SSH Tunnel. Reproduction steps:

- Connect to the database server with SSH Tunnel, saved both the
password.
- Disabled the network and Reset the Layout.
- Expand the Servers node and try to connect the same database
server.

On Thu, Nov 21, 2019 at 11:58 AM Aditya Toshniwal <
aditya(dot)toshniwal(at)enterprisedb(dot)com> wrote:

> Hi,
>
> I forgot to mention, I've also changed the dashboard code. The dashboard
> was sending graph data requests, but when the server lost connection the
> requests remains pending for longer time. Because of this the server gets
> flooded with lot of pending request and in turn slowing down the entire
> application.
> Code is changed so that only a certain number of requests remain pending
> (currently 3), above which the request won't be sent.
>
> On Thu, Nov 21, 2019 at 11:50 AM Aditya Toshniwal <
> aditya(dot)toshniwal(at)enterprisedb(dot)com> wrote:
>
>> Hi Hackers,
>>
>> Attached is the updated patch to fix the review comments.
>> Please note, there is some problem with psycopg2/libpq where it hangs
>> when network is lost - https://github.com/psycopg/psycopg2/issues/561
>> I've also changed the code to make connections after the "Servers" node
>> is expanded to fix - RM4933, so that the servers are listed first.
>>
>> Kindly review.
>>
>> On Fri, Nov 15, 2019 at 2:34 PM Akshay Joshi <
>> akshay(dot)joshi(at)enterprisedb(dot)com> wrote:
>>
>>> Hi Aditya
>>>
>>> Following are the review comments:
>>>
>>> 1. The default connection timeout should be *10* seconds.
>>> 2. In case the network is disabled and when we expand the "Servers"
>>> node the database server(for which network is disabled) should be shown in
>>> the disconnected state.
>>> 3. For the above case when you try to connect to the server and at
>>> the same time trying to fetch the properties of the valid database server,
>>> it takes long time to fetch it.
>>> 4. Case when the network is disabled, the database servers password
>>> is saved and pgAdmin4 tries to connect the server, after connection
>>> timeout, there is no message to the user, only spinner gets disappeared. We
>>> should show a message.
>>> 5. We should improve the error messages "timeout expired" and
>>> "Connection to the servers has been lost." to the more meaningful messages
>>> like "Check the network settings, check the firewall status."
>>> 6. Install database server on Windows and Enable Windows Firewall.
>>> Try to connect to the same database server. Spinner is not showing, as a
>>> user I am not able to understand is there any action started at the backend
>>> or not. As a user, I'll keep trying to connect multiple times and after the
>>> connection timeout of each request dialog pops up.
>>>
>>>
>>> On Thu, Nov 14, 2019 at 12:15 PM Aditya Toshniwal <
>>> aditya(dot)toshniwal(at)enterprisedb(dot)com> wrote:
>>>
>>>> Hi Hackers,
>>>>
>>>> Attached is the workaround patch to set the default connection timeout
>>>> to 30 seconds instead of the current value of infinite - 0, zero. The input
>>>> is present in the server properties dialogs advanced tab. The workaround
>>>> applies to the RM4724 as well.
>>>> The permanent solution would be to expand the nodes asynchronously -
>>>> https://redmine.postgresql.org/issues/4933
>>>>
>>>> Also fixed a bug where sql editor is not closing if the server is
>>>> disconnected in between.
>>>>
>>>> Kindly review.
>>>>
>>>> --
>>>> Thanks and Regards,
>>>> Aditya Toshniwal
>>>> Sr. Software Engineer | EnterpriseDB India | Pune
>>>> "Don't Complain about Heat, Plant a TREE"
>>>>
>>>
>>>
>>> --
>>> *Thanks & Regards*
>>> *Akshay Joshi*
>>>
>>> *Sr. Software Architect*
>>> *EnterpriseDB Software India Private Limited*
>>> *Mobile: +91 976-788-8246*
>>>
>>
>>
>> --
>> Thanks and Regards,
>> Aditya Toshniwal
>> Sr. Software Engineer | EnterpriseDB India | Pune
>> "Don't Complain about Heat, Plant a TREE"
>>
>
>
> --
> Thanks and Regards,
> Aditya Toshniwal
> Sr. Software Engineer | EnterpriseDB India | Pune
> "Don't Complain about Heat, Plant a TREE"
>

--
*Thanks & Regards*
*Akshay Joshi*

*Sr. Software Architect*
*EnterpriseDB Software India Private Limited*
*Mobile: +91 976-788-8246*