Re: [HACKERS] Increase Vacuum ring buffer.

On Wed, Jul 26, 2017 at 1:39 PM, Sokolov Yura
<funny.falcon@postgrespro.ru> wrote:
> On 2017-07-24 12:41, Sokolov Yura wrote:
> test_master_1/pretty.log
...
> time   activity      tps  latency   stddev      min      max
> 11130     av+ch      198    198ms    374ms      7ms   1956ms
> 11160     av+ch      248    163ms    401ms      7ms   2601ms
> 11190     av+ch      321    125ms    363ms      7ms   2722ms
> 11220     av+ch     1155     35ms    123ms      7ms   2668ms
> 11250     av+ch     1390     29ms     79ms      7ms   1422ms

vs

> test_master_ring16_1/pretty.log
> time   activity      tps  latency   stddev      min      max
> 11130     av+ch       26   1575ms    635ms    101ms   2536ms
> 11160     av+ch       25   1552ms    648ms     58ms   2376ms
> 11190     av+ch       32   1275ms    726ms     16ms   2493ms
> 11220     av+ch       23   1584ms    674ms     48ms   2454ms
> 11250     av+ch       35   1235ms    777ms     22ms   3627ms

That's a very huge change in latency for the worse

Are you sure that's the ring buffer's doing and not some methodology snafu?