Re: POC: Better infrastructure for automated testing of concurrency issues

On Fri, Dec 4, 2020 at 9:29 PM Alvaro Herrera <alvherre(at)alvh(dot)no-ip(dot)org> wrote:
> On 2020-Nov-25, Alexander Korotkov wrote:
> > In the view of above, I'd like to propose a POC patch, which implements new
> > builtin infrastructure for reproduction of concurrency issues in automated
> > test suites. The general idea is so-called "stop events", which are
> > special places in the code, where the execution could be stopped on some
> > condition. Stop event also exposes a set of parameters, encapsulated into
> > jsonb value. The condition over stop event parameters is defined using
> > jsonpath language.
>
> +1 for the idea. I agree we have a need for something on this area;
> there are *many* scenarios currently untested because of the lack of
> what you call "stop points". I don't know if jsonpath is the best way
> to implement it, but at least it is readily available and it seems a
> decent way to go at it.

Thank you for your feedback. I agree with you regarding jsonpath. My
initial idea was to use the executor expressions. But executor
expressions require serialization/deserialization, while stop points
need to work cross-database or even with processes not connected to
any database (such as checkpointer, background writer etc). That
leads to difficulties, while jsonpath appears to be very easy for this
use-case.

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Regards,
Alexander Korotkov