Ron Johnson <ronljohnsonjr(at)gmail(dot)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.
regards, tom lane