Zuul 2.6.2: Concurrency protection configuration off by 1 ? (zuul.origin.<route>.concurrency.max.requests)

[pcabot]

Hi,
Problem
While configuring the latest Zuul (2.6.2) concurrency protection mechanism, I found out that Zuul will accept 1 more connection than the limit.

Example
For instance, with the following config:

zuul.origin.api.concurrency.protect.enabled=true
zuul.origin.api.concurrency.max.requests=30

I can send 31 requests without being throttled, i.e. the 32nd connection is actually blocked.

Code
After looking at the code, it looks like this was done by design (or a bug?) where the concurrent counter is incremented after checking for the limit in BasicNettyOrigin.java (or >= should be used instead ?) :

    @Override
    public void preRequestChecks(HttpRequestMessage zuulRequest) {
        if (concurrencyProtectionEnabled.get() && concurrentRequests.get() > concurrencyMax.get()) {
            rejectedRequests.increment();
            throw new OriginConcurrencyExceededException(getName());
        }

        concurrentRequests.incrementAndGet();
    }

Question
Is this a known issue or is it by design ?
(of course, in my case I can just increment the max+1 to fix the issue, but I wanted to check)

Thanks!