Re: Problems with listen / notify

On 06/18/2014 04:33 PM, Karsten Hilbert wrote:
> On Wed, Jun 18, 2014 at 04:14:46PM +0200, Rafael Martinez wrote:
>
>> When executing multiple notifies in a server *without* problems, a
>> python script gets all notifies defined in a period of time in one
>> poll() call (as expected)
>>
>> But when running the same code against a server *with* problems, the
>> python script gets only one notify per poll() call.
>
> What constitutes a server "with" or "without" problems ?
>
> I seem to remember that notify does not guarantuee to deliver
> each of successive identical notifications.
>

Hello

I don't care about the order in which the script receives notifications.
My problem is that I have a particular postgreSQL server that sends only
one notification per poll() call.

A have a program that checks for new notifications from a database one
time every minute. In a "normal" server the program gets all the
notifications generated by the database during the last minute, in the
server with "problems" it gets only one every minute even if many
notifications has been generated during the last minute.

During a minute the database can generate several hundreds
notifications, if the program connects to the server with "problems", it
can take several hours to process all the notifications, while when it
is connected to a normal server it takes a few seconds.

I am just trying to understand why this server behaves in this way when
it is not overloaded at all.

Thanks for your help.

regards,
--
Rafael Martinez Guerrero
Center for Information Technology
University of Oslo, Norway

PGP Public Key: http://folk.uio.no/rafael/