Jersey update from 3.1.3 to 3.1.4 slows down our external service response times drastically

[rehmatt]

Hi,

we've recently updated our services from jersey 3.1.2 to 3.1.5 and encountered drastically worse response times for our external service calls which are using jerseys HttpUrlConnector.

With downgrading to 3.1.3 everything was fine again, but updating to 3.1.4 again let the response times rise by 50% to 120%.

Having a look on the changes between 3.1.3 and 3.1.4 I saw the following PR: #5359.
It introduced a synchronized block inside getConnection(URL url, Proxy proxy):

default HttpURLConnection getConnection(URL url, Proxy proxy) throws IOException {
    synchronized (this){
        return (proxy == null) ? getConnection(url) : (HttpURLConnection) url.openConnection(proxy);
    }
}

If I interpret it correctly this will lead to only one thread being able to open a connection with the connector. As we have many threads processing incoming requests with one connector per external service, it might happen that there are many threads which want to get a connection, but only one at a time is possible.

Is this already a known issue? Is my assumption regarding the synchronized block correct?

[fwippe]

Just to put this into perspective: If I'm not mistaken, the fact that getConnection is synchronized on HttpUrlConnector ultimately means that only one connection at a time may be created across all services handled by Jersey. This is potentially a catastrophic performance regression.

[jankadel]

Great finding! I was wondering why my services became slower when I upgraded Jersey.