Re: [HACKERS] Re: [COMMITTERS] pgsql: Remove pgbench "progress" test pending solution of its timing is (fwd)

On 18/07/18 22:56, Fabien COELHO wrote:
>
> Hello Heikki,
>
>>> Yep. The attached version does only the tailing stuff under -R and not all
>>> threads were stopped on errors, with comments to tell about the why.
>>
>> Hmm. How about we just remove this special case from doCustom():
>>
>>> case CSTATE_START_THROTTLE:
>>> // ...
>>> if (duration > 0 && st->txn_scheduled > end_time)
>>> {
>>> st->state = CSTATE_FINISHED;
>>> break;
>>> }
>>
>> That way, we let the client go into CSTATE_THROTTLE state, even though we
>> know that the timer will run out before we reach txn_scheduled. Then it will
>> work the way we want, right? One small difference is that then the clients
>> will keep the connections open longer, until the timer expires, but I think
>> that's reasonable. Less surprising than the current behavior, even.
>
> Hmmm... in this instance, and if this test is removed, ISTM that it can
> start the transaction, re-establishing a connection under --connect, and
> the transaction will run to its end even if it is beyond the expected end
> of run. So removing this test does not seem desirable.

Can you elaborate? I don't think that's how it works. In threadRun(), we
have this:

> for (i = 0; i < nstate; i++)
> {
> CState *st = &state[i];
>
> if (st->state == CSTATE_THROTTLE && timer_exceeded)
> {
> /* interrupt client that has not started a transaction */
> st->state = CSTATE_FINISHED;
> finishCon(st);
> remains--;
> }
> else if (st->state == CSTATE_SLEEP || st->state == CSTATE_THROTTLE)
> ...

As soon as the -T timer is exceeded, the above code will close all
connections that are in CSTATE_THROTTLE state.

- Heikki