Slow performance when generating a lot of request on high-spec BAREMETAL server

[roggerdug]

Issue:
Inserting many records into a localhost database takes a long time on a high-spec BAREMETAL server, much slower than a low-spec VM.

Replicate issue:
Wrote a script on localhost. The script will:

• 1. create process A (listen on localhost:8080)
  2. create process B, send 10Mb to process A over TCP (localhost:8080). Repeat 10000 times
  3. create process B, send 1Gb to process A over TCP (localhost:8080). Repeat 10 times
  4. complete. calculate total time used

• Data is sent over TCP, it will not write anything on disk.

On VM (CentOS 7.9) running 4 vCPU, 4GB vRAM:
12 seconds to complete 10Mb (10000 times)
5 seconds to complete 1Gb (10 times)

On BAREMETAL server (CentOS 7.9) running 64 core CPU, 400G RAM:
35 seconds to complete 10Mb (10000 times). why?
5 seconds to complete 1Gb (10 times)

Checklist:

• 1. vnstat, ifconfig, cbm - no network bottleneck, no error, no packet drop on localhost
  2. sar & htop - no resource bottleneck
  3. swap - no swapping occured

Why is the BAREMETAL server so much slower than a low-spec VM? Any advise is appreciated.

[BShT]

look at your data base conf and /etc/sysctl.conf

ps: disk speed?