Shenandoah performance

[Aleksey Shipilev]

Hi,

On 10/6/20 7:55 PM, Frédéric Poliquin wrote:
> The CPU is generally 10 to 20 % higher and when the load exceeds 50 %, we experience « stop the
> world » collections that last for 5 to 7 seconds many times per minute which leads to very poor
> response time.
Sounds like application is routinely outpacing the GC.
The excerpt from the GC log would tell quite a bit more.

> Is there any recommandation or best practice that we could use, any advice, is this a normal
> behavior for Shenandoah
Please read:
   https://wiki.openjdk.java.net/display/Shenandoah#Main-PerformanceGuidelinesandDiagnostics

> I always tried to keep the heap as small as possible but should we increase resource allocation
> and reduce the number of pods ?
Concurrent GCs (especially non-generational yet, like Shenandoah) need more free heap to catch up 
with allocations, otherwise they would have to stall. So, giving it more heap might just be enough. 
But it is hard to tell without looking at a GC log.

-- 
Thanks,
-Aleksey