Virtual vs platform performance at 10K HTTP requests

[Alan Bateman]

On 26/11/2025 10:32, David wrote:
>
>     I assume it also benefits from being able to use HTTP persistent
>     connections.
>
>
> Just trying to understand, does that mean that virtual threads don't 
> have this? Because running Socket Statistics in the background showing 
> 17K established connections while running virtual threads vs 140 when 
> using platform threads.
>
> At this point I am just trying to understand where this delay is 
> coming from and why virtual threads trigger this.
>
Persistent connections avoid needing a separate TCP connection for each 
request. LoomBenchmark's FixedPlatformPool appears to use a thread pool 
with 4 workers so it gets to benefit from the having the cached 
connection. Tomcat probably has more configuration to limit/configure 
the number connections to keep alive, probably 100 or 200 by default. 
LoomBenchmark.java's virtualThreadExecutor is a completely different 
test. It attempts to establish 10k concurrent connections, it's probably 
causing connections to be closed and re-established at each iteration.

-Alan
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