Upgrade from Spring Boot 3.3.1 to Spring Boot 3.4.1 appears to have caused performance regression

[frankjkelly]

We are seeing this at the median and p99 across multiple services

API Service 1
Before

After (this reaches less than half the load of the "before" test case)

API for Service 2
Before

After (this also reaches less than half the load of the "before" test case)

The only thing we see so far that might explain is that the Hikari Connection Pool (for our Postgres DB) seems higher in both cases
suggesting either Postgres Driver / Hibernate / JPA may be involved potentially.

[wilkinsona]

Thanks for the report. Unfortunately, it isn’t actionable in its current form as it provides only minimal information about the affected services and how they’re implemented.

You’ve mentioned Postgres. Best guess at the moment is that this is similar to the performance problems mentioned in the comments on #44214.

[frankjkelly]

@wilkinsona Thanks yeah I figured it wasn't enough but just in case other someone else pieces it all together before we do hopefully they might drop an idea here.

Thanks for the Postgres idea sadly it doesn't match our case (however it is good to know of those issues in 42.7.5 for sure)

[LeoTheDarvin]

Hello, @frankjkelly . Is the issue relevant for you still?