Re: testing HS/SR - 1 vs 2 performance

On Sat, April 10, 2010 01:23, Erik Rijkers wrote:
> Using 9.0devel cvs HEAD, 2010.04.08.
>
> I am trying to understand the performance difference
> between primary and standby under a standard pgbench
> read-only test.
>
> server has 32 GB, 2 quadcores.
>
> primary:
> tps = 34606.747930 (including connections establishing)
> tps = 34527.078068 (including connections establishing)
> tps = 34654.297319 (including connections establishing)
>
> standby:
> tps = 700.346283 (including connections establishing)
> tps = 717.576886 (including connections establishing)
> tps = 740.522472 (including connections establishing)
>
> transaction type: SELECT only
> scaling factor: 1000
> query mode: simple
> number of clients: 20
> number of threads: 1
> duration: 900 s
>
> both instances have
> max_connections = 100
> shared_buffers = 256MB
> checkpoint_segments = 50
> effective_cache_size= 16GB
>
> See also:
>
> http://archives.postgresql.org/pgsql-testers/2010-04/msg00005.php
> (differences with scale 10_000)
>

To my surprise, I have later seen the opposite behaviour with the standby giving fast runs, and
the primary slow.

FWIW, I've overnight run a larget set of tests. (against same 9.0devel
instances as the ones from the earlier email).

These results are generally more balanced.

for scale in
for clients in 1 5 10 20
for port in 6565 6566 --> primaryport standbyport
for run in `seq 1 3`
pgbench ...
sleep ((scale / 10) * 60)
done
done
done
done

(so below, alternating 3 primary, followed by 3 standby runs)

scale: 10 clients: 1 tps = 15219.019272 pgbench -h /tmp -p 6565 -n -S -c 1 -T 900 -j 1
scale: 10 clients: 1 tps = 15301.847615 pgbench -h /tmp -p 6565 -n -S -c 1 -T 900 -j 1
scale: 10 clients: 1 tps = 15238.907436 pgbench -h /tmp -p 6565 -n -S -c 1 -T 900 -j 1
scale: 10 clients: 1 tps = 12129.928289 pgbench -h /tmp -p 6566 -n -S -c 1 -T 900 -j 1
scale: 10 clients: 1 tps = 12151.711589 pgbench -h /tmp -p 6566 -n -S -c 1 -T 900 -j 1
scale: 10 clients: 1 tps = 12203.494512 pgbench -h /tmp -p 6566 -n -S -c 1 -T 900 -j 1
scale: 10 clients: 5 tps = 60248.120599 pgbench -h /tmp -p 6565 -n -S -c 5 -T 900 -j 1
scale: 10 clients: 5 tps = 60827.949875 pgbench -h /tmp -p 6565 -n -S -c 5 -T 900 -j 1
scale: 10 clients: 5 tps = 61167.447476 pgbench -h /tmp -p 6565 -n -S -c 5 -T 900 -j 1
scale: 10 clients: 5 tps = 50750.385403 pgbench -h /tmp -p 6566 -n -S -c 5 -T 900 -j 1
scale: 10 clients: 5 tps = 50600.891436 pgbench -h /tmp -p 6566 -n -S -c 5 -T 900 -j 1
scale: 10 clients: 5 tps = 50486.857610 pgbench -h /tmp -p 6566 -n -S -c 5 -T 900 -j 1
scale: 10 clients: 10 tps = 60307.739327 pgbench -h /tmp -p 6565 -n -S -c 10 -T 900 -j 1
scale: 10 clients: 10 tps = 60264.230349 pgbench -h /tmp -p 6565 -n -S -c 10 -T 900 -j 1
scale: 10 clients: 10 tps = 60146.370598 pgbench -h /tmp -p 6565 -n -S -c 10 -T 900 -j 1
scale: 10 clients: 10 tps = 50455.537671 pgbench -h /tmp -p 6566 -n -S -c 10 -T 900 -j 1
scale: 10 clients: 10 tps = 49877.000813 pgbench -h /tmp -p 6566 -n -S -c 10 -T 900 -j 1
scale: 10 clients: 10 tps = 50097.949766 pgbench -h /tmp -p 6566 -n -S -c 10 -T 900 -j 1
scale: 10 clients: 20 tps = 43355.220657 pgbench -h /tmp -p 6565 -n -S -c 20 -T 900 -j 1
scale: 10 clients: 20 tps = 43352.725422 pgbench -h /tmp -p 6565 -n -S -c 20 -T 900 -j 1
scale: 10 clients: 20 tps = 43496.085623 pgbench -h /tmp -p 6565 -n -S -c 20 -T 900 -j 1
scale: 10 clients: 20 tps = 37169.126299 pgbench -h /tmp -p 6566 -n -S -c 20 -T 900 -j 1
scale: 10 clients: 20 tps = 37100.260450 pgbench -h /tmp -p 6566 -n -S -c 20 -T 900 -j 1
scale: 10 clients: 20 tps = 37342.758507 pgbench -h /tmp -p 6566 -n -S -c 20 -T 900 -j 1
scale: 100 clients: 1 tps = 12514.185089 pgbench -h /tmp -p 6565 -n -S -c 1 -T 900 -j 1
scale: 100 clients: 1 tps = 12542.842198 pgbench -h /tmp -p 6565 -n -S -c 1 -T 900 -j 1
scale: 100 clients: 1 tps = 12595.688640 pgbench -h /tmp -p 6565 -n -S -c 1 -T 900 -j 1
scale: 100 clients: 1 tps = 10435.681851 pgbench -h /tmp -p 6566 -n -S -c 1 -T 900 -j 1
scale: 100 clients: 1 tps = 10456.983353 pgbench -h /tmp -p 6566 -n -S -c 1 -T 900 -j 1
scale: 100 clients: 1 tps = 10434.213044 pgbench -h /tmp -p 6566 -n -S -c 1 -T 900 -j 1
scale: 100 clients: 5 tps = 48682.166988 pgbench -h /tmp -p 6565 -n -S -c 5 -T 900 -j 1
scale: 100 clients: 5 tps = 48656.883485 pgbench -h /tmp -p 6565 -n -S -c 5 -T 900 -j 1
scale: 100 clients: 5 tps = 48687.894655 pgbench -h /tmp -p 6565 -n -S -c 5 -T 900 -j 1
scale: 100 clients: 5 tps = 41901.629933 pgbench -h /tmp -p 6566 -n -S -c 5 -T 900 -j 1
scale: 100 clients: 5 tps = 41953.386791 pgbench -h /tmp -p 6566 -n -S -c 5 -T 900 -j 1
scale: 100 clients: 5 tps = 41787.962712 pgbench -h /tmp -p 6566 -n -S -c 5 -T 900 -j 1
scale: 100 clients: 10 tps = 48704.247239 pgbench -h /tmp -p 6565 -n -S -c 10 -T 900 -j 1
scale: 100 clients: 10 tps = 48941.190050 pgbench -h /tmp -p 6565 -n -S -c 10 -T 900 -j 1
scale: 100 clients: 10 tps = 48603.077936 pgbench -h /tmp -p 6565 -n -S -c 10 -T 900 -j 1
scale: 100 clients: 10 tps = 42948.666272 pgbench -h /tmp -p 6566 -n -S -c 10 -T 900 -j 1
scale: 100 clients: 10 tps = 42767.793899 pgbench -h /tmp -p 6566 -n -S -c 10 -T 900 -j 1
scale: 100 clients: 10 tps = 42612.670983 pgbench -h /tmp -p 6566 -n -S -c 10 -T 900 -j 1
scale: 100 clients: 20 tps = 36350.454258 pgbench -h /tmp -p 6565 -n -S -c 20 -T 900 -j 1
scale: 100 clients: 20 tps = 36373.088111 pgbench -h /tmp -p 6565 -n -S -c 20 -T 900 -j 1
scale: 100 clients: 20 tps = 36490.886781 pgbench -h /tmp -p 6565 -n -S -c 20 -T 900 -j 1
scale: 100 clients: 20 tps = 32235.811228 pgbench -h /tmp -p 6566 -n -S -c 20 -T 900 -j 1
scale: 100 clients: 20 tps = 32253.837906 pgbench -h /tmp -p 6566 -n -S -c 20 -T 900 -j 1
scale: 100 clients: 20 tps = 32144.189047 pgbench -h /tmp -p 6566 -n -S -c 20 -T 900 -j 1
scale: 500 clients: 1 tps = 11733.254970 pgbench -h /tmp -p 6565 -n -S -c 1 -T 900 -j 1
scale: 500 clients: 1 tps = 11726.665739 pgbench -h /tmp -p 6565 -n -S -c 1 -T 900 -j 1
scale: 500 clients: 1 tps = 11617.622548 pgbench -h /tmp -p 6565 -n -S -c 1 -T 900 -j 1
scale: 500 clients: 1 tps = 9769.861175 pgbench -h /tmp -p 6566 -n -S -c 1 -T 900 -j 1
scale: 500 clients: 1 tps = 9878.465752 pgbench -h /tmp -p 6566 -n -S -c 1 -T 900 -j 1
scale: 500 clients: 1 tps = 9808.236216 pgbench -h /tmp -p 6566 -n -S -c 1 -T 900 -j 1
scale: 500 clients: 5 tps = 45185.900553 pgbench -h /tmp -p 6565 -n -S -c 5 -T 900 -j 1
scale: 500 clients: 5 tps = 45170.334037 pgbench -h /tmp -p 6565 -n -S -c 5 -T 900 -j 1
scale: 500 clients: 5 tps = 45136.596374 pgbench -h /tmp -p 6565 -n -S -c 5 -T 900 -j 1
scale: 500 clients: 5 tps = 39231.863815 pgbench -h /tmp -p 6566 -n -S -c 5 -T 900 -j 1
scale: 500 clients: 5 tps = 39336.889619 pgbench -h /tmp -p 6566 -n -S -c 5 -T 900 -j 1
scale: 500 clients: 5 tps = 39269.483772 pgbench -h /tmp -p 6566 -n -S -c 5 -T 900 -j 1
scale: 500 clients: 10 tps = 45468.080680 pgbench -h /tmp -p 6565 -n -S -c 10 -T 900 -j 1
scale: 500 clients: 10 tps = 45727.159963 pgbench -h /tmp -p 6565 -n -S -c 10 -T 900 -j 1
scale: 500 clients: 10 tps = 45399.241367 pgbench -h /tmp -p 6565 -n -S -c 10 -T 900 -j 1
scale: 500 clients: 10 tps = 40759.108042 pgbench -h /tmp -p 6566 -n -S -c 10 -T 900 -j 1
scale: 500 clients: 10 tps = 40783.287718 pgbench -h /tmp -p 6566 -n -S -c 10 -T 900 -j 1
scale: 500 clients: 10 tps = 40858.007847 pgbench -h /tmp -p 6566 -n -S -c 10 -T 900 -j 1
scale: 500 clients: 20 tps = 34729.742313 pgbench -h /tmp -p 6565 -n -S -c 20 -T 900 -j 1
scale: 500 clients: 20 tps = 34705.119029 pgbench -h /tmp -p 6565 -n -S -c 20 -T 900 -j 1
scale: 500 clients: 20 tps = 34617.517224 pgbench -h /tmp -p 6565 -n -S -c 20 -T 900 -j 1
scale: 500 clients: 20 tps = 31252.355034 pgbench -h /tmp -p 6566 -n -S -c 20 -T 900 -j 1
scale: 500 clients: 20 tps = 31234.885791 pgbench -h /tmp -p 6566 -n -S -c 20 -T 900 -j 1
scale: 500 clients: 20 tps = 31273.307637 pgbench -h /tmp -p 6566 -n -S -c 20 -T 900 -j 1
scale: 1000 clients: 1 tps = 220.024691 pgbench -h /tmp -p 6565 -n -S -c 1 -T 900 -j 1
scale: 1000 clients: 1 tps = 294.855794 pgbench -h /tmp -p 6565 -n -S -c 1 -T 900 -j 1
scale: 1000 clients: 1 tps = 375.152757 pgbench -h /tmp -p 6565 -n -S -c 1 -T 900 -j 1
scale: 1000 clients: 1 tps = 295.965959 pgbench -h /tmp -p 6566 -n -S -c 1 -T 900 -j 1
scale: 1000 clients: 1 tps = 1036.517110 pgbench -h /tmp -p 6566 -n -S -c 1 -T 900 -j 1
scale: 1000 clients: 1 tps = 9167.012603 pgbench -h /tmp -p 6566 -n -S -c 1 -T 900 -j 1
scale: 1000 clients: 5 tps = 1241.224282 pgbench -h /tmp -p 6565 -n -S -c 5 -T 900 -j 1
scale: 1000 clients: 5 tps = 1894.806301 pgbench -h /tmp -p 6565 -n -S -c 5 -T 900 -j 1
scale: 1000 clients: 5 tps = 18532.885549 pgbench -h /tmp -p 6565 -n -S -c 5 -T 900 -j 1
scale: 1000 clients: 5 tps = 1497.491279 pgbench -h /tmp -p 6566 -n -S -c 5 -T 900 -j 1
scale: 1000 clients: 5 tps = 1480.164166 pgbench -h /tmp -p 6566 -n -S -c 5 -T 900 -j 1
scale: 1000 clients: 5 tps = 3470.769236 pgbench -h /tmp -p 6566 -n -S -c 5 -T 900 -j 1
scale: 1000 clients: 10 tps = 2414.552333 pgbench -h /tmp -p 6565 -n -S -c 10 -T 900 -j 1
scale: 1000 clients: 10 tps = 19248.609443 pgbench -h /tmp -p 6565 -n -S -c 10 -T 900 -j 1
scale: 1000 clients: 10 tps = 45059.231609 pgbench -h /tmp -p 6565 -n -S -c 10 -T 900 -j 1
scale: 1000 clients: 10 tps = 1648.526373 pgbench -h /tmp -p 6566 -n -S -c 10 -T 900 -j 1
scale: 1000 clients: 10 tps = 3659.800008 pgbench -h /tmp -p 6566 -n -S -c 10 -T 900 -j 1
scale: 1000 clients: 10 tps = 35900.769857 pgbench -h /tmp -p 6566 -n -S -c 10 -T 900 -j 1
scale: 1000 clients: 20 tps = 2462.855864 pgbench -h /tmp -p 6565 -n -S -c 20 -T 900 -j 1
scale: 1000 clients: 20 tps = 27168.407568 pgbench -h /tmp -p 6565 -n -S -c 20 -T 900 -j 1
scale: 1000 clients: 20 tps = 34438.802096 pgbench -h /tmp -p 6565 -n -S -c 20 -T 900 -j 1
scale: 1000 clients: 20 tps = 2933.220489 pgbench -h /tmp -p 6566 -n -S -c 20 -T 900 -j 1
scale: 1000 clients: 20 tps = 25586.972428 pgbench -h /tmp -p 6566 -n -S -c 20 -T 900 -j 1
scale: 1000 clients: 20 tps = 30926.189621 pgbench -h /tmp -p 6566 -n -S -c 20 -T 900 -j 1