Java 11 Http2Client thread leak.

[czubin]

We noticed that the feign.http2client.Http2Client during high load will generate a lot of inactive threadsL:

Namely during the execute part the client will call the getOrCreateClient() method.

If the Http2Client was created using the default constructor.
Then the getOrCreateClient() method will always create a new http client along with a new threadpool.

This is because the options supplied during the request do not match the options used during the initial creation.
I.e. the code
client.connectTimeout() .map(timeout -> timeout.toMillis() != options.connectTimeoutMillis()) .orElse(true); will always return true.

Hence during each request a new client is instantiated along with a new threadpool.
During high load this will cause the application to run out of memory.