Re: pgbench throttling latency limit - Mailing list pgsql-hackers

From Amit Langote
Subject Re: pgbench throttling latency limit
Date
Msg-id 5628AE68.4090204@lab.ntt.co.jp
Whole thread Raw
In response to Re: pgbench throttling latency limit  (Fabien COELHO <coelho@cri.ensmp.fr>)
Responses Re: pgbench throttling latency limit  (Fabien COELHO <coelho@cri.ensmp.fr>)
List pgsql-hackers
On 2015/10/22 18:20, Fabien COELHO wrote:
>>
>>> progress: 365.0 s, 18392.1 tps, lat 94.857 ms stddev 23.917, lag 90.980
>>> ms, 106244 skipped
>>>
>>> 100k skipped transactions at a rate limit of 40k? That doesn't seem right.
>>
>> Argh. It's just because I used -P5. It's a bit confusing that the other
>> options are per second, and this is per interval...
> 
> I agree, but I'm unsure of a fix, beyond what is already done which is to
> show units next to the figures...
> 
> ISTM that people expect "tps" for performance, even on several seconds.
> When it comes to skipped transactions, a count seemed more natural. I
> really just see this as an indicator that things are not going smoothly.
> 
> Maybe it could be shown as a percentage of scheduled transactions,
> possibly with an option?
> 
> A mitigation is to always run with -P 1 :-).

Wouldn't printing average (per second) over the interval work?

Thanks,
Amit




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