Thread: Postgres process count GCC vs Clang is Different on autovaccum=on

Postgres process count GCC vs Clang is Different on autovaccum=on

From

hpc researcher_mspk

Date:

24 November 2021, 15:05:50

Software/Hardware used:

===================

PostgresV14.v
OS: RHELv8.4
Benchmark:HammerDB v4.3
Hardware used: Apple/AMD Ryzen.
RAM size: 256 GB
SSD/HDD: 1TB
CPU(s): 256(0-255)
Thread(s) per core: 2
Core(s) per socket: 64
Socket(s): 2
NUMA node(s): 8

Command used to count process: ps -eaf | grep postgres

Case1: AutoVaccum=on

vu	GCC	Clang
32	43	42
64	76	74
192	203	202
250	262	262

Case2:AutoVaccum=off

vu	GCC	Clang
32	40	40
64	72	72
192	200	200
250	261	263

In Case1 why is the process different in Clang vs GCC.
In postgresql process dependent wrt compiler GCC/Clang?
Is any recommendation or suggestion to check on this in Postgresv14

Re: Postgres process count GCC vs Clang is Different on autovaccum=on

From

Tomas Vondra

Date:

24 November 2021, 15:22:00


On 11/24/21 13:05, hpc researcher_mspk wrote:
> Software/Hardware used:
> ===================
> PostgresV14.v
> OS: RHELv8.4
> Benchmark:HammerDB v4.3
> Hardware used: Apple/AMD Ryzen.
> RAM size: 256 GB
> SSD/HDD: 1TB
> CPU(s): 256(0-255)
> Thread(s) per core:  2
> Core(s) per socket:  64
> Socket(s):           2
> NUMA node(s):        8
> 
> Command used to count process: ps -eaf | grep postgres
> 
> Case1: AutoVaccum=on
> vu    GCC    Clang
> 32    43    42
> 64    76    74
> 192    203    202
> 250    262    262
> 
> 
> Case2:AutoVaccum=off
> vu    GCC    Clang
> 32    40    40
> 64    72    72
> 192    200    200
> 250    261    263
> 
> 
> In Case1 why is the process different in Clang vs GCC.
> In postgresql process dependent wrt compiler GCC/Clang?

No, it's not. The most likely explanation is that you're seeing 
different number of autovacuum workers. Those are dynamic, i.e. may 
appear/disappear. Or maybe there are more connections to the DB.


regards

-- 
Tomas Vondra
EnterpriseDB: http://www.enterprisedb.com
The Enterprise PostgreSQL Company