Re: Speed up Clog Access by increasing CLOG buffers

On Fri, Oct 21, 2016 at 7:57 AM, Dilip Kumar <dilipbalaut(at)gmail(dot)com> wrote:
> On Thu, Oct 20, 2016 at 9:03 PM, Tomas Vondra
> <tomas(dot)vondra(at)2ndquadrant(dot)com> wrote:
>
>> In the results you've posted on 10/12, you've mentioned a regression with 32
>> clients, where you got 52k tps on master but only 48k tps with the patch (so
>> ~10% difference). I have no idea what scale was used for those tests,
>
> That test was with scale factor 300 on POWER 4 socket machine. I think
> I need to repeat this test with multiple reading to confirm it was
> regression or run to run variation. I will do that soon and post the
> results.

As promised, I have rerun my test (3 times), and I did not see any regression.
Median of 3 run on both head and with group lock patch are same.
However I am posting results of all three runs.

I think in my earlier reading, we saw TPS ~48K with the patch, but I
think over multiple run we get this reading with both head as well as
with patch.

Head:
--------
run1:

transaction type: <builtin: TPC-B (sort of)>
scaling factor: 300
query mode: prepared
number of clients: 32
number of threads: 32
duration: 1800 s
number of transactions actually processed: 87784836
latency average = 0.656 ms
tps = 48769.327513 (including connections establishing)
tps = 48769.543276 (excluding connections establishing)

run2:
transaction type: <builtin: TPC-B (sort of)>
scaling factor: 300
query mode: prepared
number of clients: 32
number of threads: 32
duration: 1800 s
number of transactions actually processed: 91240374
latency average = 0.631 ms
tps = 50689.069717 (including connections establishing)
tps = 50689.263505 (excluding connections establishing)

run3:
transaction type: <builtin: TPC-B (sort of)>
scaling factor: 300
query mode: prepared
number of clients: 32
number of threads: 32
duration: 1800 s
number of transactions actually processed: 90966003
latency average = 0.633 ms
tps = 50536.639303 (including connections establishing)
tps = 50536.836924 (excluding connections establishing)

With group lock patch:
------------------------------
run1:
transaction type: <builtin: TPC-B (sort of)>
scaling factor: 300
query mode: prepared
number of clients: 32
number of threads: 32
duration: 1800 s
number of transactions actually processed: 87316264
latency average = 0.660 ms
tps = 48509.008040 (including connections establishing)
tps = 48509.194978 (excluding connections establishing)

run2:
transaction type: <builtin: TPC-B (sort of)>
scaling factor: 300
query mode: prepared
number of clients: 32
number of threads: 32
duration: 1800 s
number of transactions actually processed: 91950412
latency average = 0.626 ms
tps = 51083.507790 (including connections establishing)
tps = 51083.704489 (excluding connections establishing)

run3:
transaction type: <builtin: TPC-B (sort of)>
scaling factor: 300
query mode: prepared
number of clients: 32
number of threads: 32
duration: 1800 s
number of transactions actually processed: 90378462
latency average = 0.637 ms
tps = 50210.225983 (including connections establishing)
tps = 50210.405401 (excluding connections establishing)

--
Regards,
Dilip Kumar
EnterpriseDB: http://www.enterprisedb.com