vertx-examples | Vert.x 2.x is deprecated - use | Reactive Programming library

I am trying to understand CORS configuration with vert.x. I found an example at this github repository under the CORS section. When i tried it only POST example seemed to work (preflight.html). Since I also need to use GET (nopreflight.html) in one of my projects, I have tried to modify the example obtaining poor results. This is what i have right now:

Server.java

I want to use vert.x config modules to read json files.

Because do not like using

I am trying to implement a proxy using Vertx and Vertx client similar to https://github.com/vert-x/vertx-examples/blob/master/src/raw/java/proxy/ProxyServer.java but with router.

The exceptions are that it connects to multiple servers rather than a single one.

I have two types of services I connect to

1. Simple echo service
2. A service that sleeps for 5 seconds before echoing back

If I use a shared HttpClient for the proxy and I connect to a simple echo service I have no big latency issues, it's median is less than a second, but if I connect to a sleeping service the latency goes higher over time and load

If I hit the service directly, I get the expected latency which is on average 5100ms

Now if I change to create a new HttpClient per request it is able to give a good latency around 5110ms. However, if I use it to hit the echo version it breaks and the artillery app gives me a EADDRINUSE error (which is weird because that's usually on the listen side)

I'm using HTTP not HTTP/2 since the services are not on SSL so I have not tried the single connection multiplexing

I'm also using a conservative 64MB heap size for the proxy.

Is it more proper to create a new HttpClient and perhaps the reason for the failure is because I am just testing on an inadequate machine for ridiculous loads?

In vertx example websocket url hardcoded in html as localhost: