Control javax.ws.rs.client.Client idle connection TTL

[jimbogithub]

Is there a way to control the quarkus-rest-client idle connection TTL?

The following code will set a hard TTL:
((ResteasyClientBuilder) ClientBuilder.newBuilder()).connectionTTL(55, TimeUnit.SECONDS);

This differs from the quarkus-rest-client-reactive which does do an idle connection TTL in line with the documentation: https://quarkus.io/guides/all-config#quarkus-rest-client-config_quarkus.rest-client.-config-key-.connection-ttl

Unfortunately I can't use the quarkus-rest-client-reactive because I need the Response to be present on WebApplicationException but it is not populated.

The underlying Apache HttpClient can be configured with a ConnectionKeepAliveStrategy. This defaults to DefaultConnectionKeepAliveStrategy which honours the Keep-Alive: timeout=x in the response. However the servers that I'm talking to don't populate a sensible value and adding it via a ClientResponseFilter does not help as it appears the connection pool examines the headers before the filters are applied. There does not appear to be anyway to inject a custom ConnectionKeepAliveStrategy other than to build your own HttpClient from scratch.

The intention of the idle TTL is to discard a connection before it gets dropped by any intermediary that kills idle connections. The problem with the hard TTL is the latency introduced in establishing a new connection and having to do so unnecessarily as we are dropping perfectly valid connections.

[jimbogithub]

FWIW I've switched to directly using a Vertx WebClient. That gets all the connection pool benefits of quarkus-rest-client-reactive but avoids the WebApplicationException Response issue.

Best of all the Netty connection pool cleanly detects when the other end drops an idle connection instead of leaving a zombie the way the Apache pool does.