Re: Libpq support to connect to standby server as priority

On Wed, Jul 11, 2018 at 6:00 PM Haribabu Kommi <kommi(dot)haribabu(at)gmail(dot)com>
wrote:

>
>
> On Wed, Jul 4, 2018 at 11:14 PM Laurenz Albe <laurenz(dot)albe(at)cybertec(dot)at>
> wrote:
>
>> Haribabu Kommi wrote:
>>
>>
> - I think the construction with "read_write_host_index" makes the code
>> even more
>> complicated than it already is.
>>
>> What about keeping the first successful connection open and storing it
>> in a
>> variable if we are in "prefer-read" mode.
>> If we get the read-only connection we desire, close that cached
>> connection,
>> otherwise use it.
>>
>
> Even if we add a variable to cache the connection, I don't think the logic
> of checking
> the next host for the read-only host logic may not change, but the extra
> connection
> request to the read-write host again will be removed.
>

I evaluated your suggestion of caching the connection and reuse it when
there is no
read only server doesn't find, but I am thinking that it will add more
complexity and also
the connection to the other servers delays, the cached connection may be
closed by
the server also because of timeout.

I feel the extra time during connection may be fine, if user is preferring
the prefer-read
mode, instead of adding more complexity in handling the cached connection?

comments?

Regards,
Haribabu Kommi
Fujitsu Australia