[Postgres-xl-developers] 答复: reducing the duration of regression tests(Internet mail)
Tomas Vondra
tomas.vondra at 2ndquadrant.com
Sun Jul 9 13:20:42 PDT 2017
On 7/9/17 6:49 PM, Mason Sharp wrote:
>
>
> On Fri, Jul 7, 2017 at 12:14 PM, Tomas Vondra
> <tomas.vondra at 2ndquadrant.com <mailto:tomas.vondra at 2ndquadrant.com>> wrote:
>
> Hi,
>
> On 7/7/17 5:33 PM, Pavan Deolasee wrote:
>
>
>
> On Fri, Jul 7, 2017 at 8:34 PM, Tomas Vondra
> <tomas.vondra at 2ndquadrant.com
> <mailto:tomas.vondra at 2ndquadrant.com>
> <mailto:tomas.vondra at 2ndquadrant.com
> <mailto:tomas.vondra at 2ndquadrant.com>>> wrote:
>
> Hi,
>
> On 7/7/17 5:23 AM, jasonysli(李跃森) wrote:
>
> Hi,
> In fact, when running the PGXL regress on an advanced
> server
> with 24 cores, 64GB memory. But it still take several
> minutes,
> so I think
> maybe it indeed need so much time :)
>
>
> But doesn't that actually suggest the opposite - that the main
> resources (CPU, I/O, memory) are not the limiting factor
> here? I
> mean, if it takes minutes both on a laptop and a server
> with much
> more resources, then it probably is not about the amount of
> work, no?
>
>
> For long I wanted to compare run time for individual tests
> against PG and see if there are specific tests which are much
> slower in XL. Do you see slowdown across all tests or just
> specific ones? May be DDLs are much slower in XL?
>
>
> It's definitely a slowdown across all regression tests, although the
> slowdown varies depending on the test of course. Attached is a
> spreadsheet with timings for one "make check" run on XL 9.5 and
> PostgreSQL 9.5, and two CDF charts (cumulative distribution function).
>
> On PostgreSQL 95% of tests completes in under 1 second, while on XL
> it's only 40%. On XL the 95%-percentile is only achieved at ~10 seconds.
>
> I haven't repeated those measurements on the XL 10 code, but it
> doesn't seem to have changed significantly.
>
>
> We are adding latency going between the datanodes and GTM.
>
> Running with the coordinator generating XIDs and snapshots may speed
> things up a bit, mainly for internal testing.
>
But those tests are running on the same machine, through localhost. So
the latency is like 0.05 ms. I wouldn't expect that to make tests 10x
slower, but maybe I'm wrong.
--
Tomas Vondra http://www.2ndQuadrant.com
PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services
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