On Tue, Apr 30, 2024 at 10:07 PM Tom Lane <tgl@sss.pgh.pa.us> wrote:
Ron Johnson <ronljohnsonjr@gmail.com> writes: > When running stress tests on the systems (in prod, during the maintenance > window), 171K events/second are generated on the RHEL8 servers, and CB > needs (according to top(1)) 325% of CPU to handle that, and still dropping > 92% of them. > The RHEL6 system doesn't bat an eye at running the exact same test (36 cron > jobs running psql executing SELECT statements).
Is JIT enabled on the newer system? If so try turning it off, or else raise the associated cost settings. We've seen lots of reports of workloads where, by default, the planner is too aggressive about applying JIT.
A puzzling suggestion. Why should it impact AV software?
At one point, I disabled JIT to test its impact on PG, performance was a bit of a wash (some queries were a bit faster, some were a bit slower), but I didn't monitor CB.
Just now, I did ALTER SYSTEM SET jit='off'; and re-ran the stress test. No impact to CarbonBlack.