@Override
        public void dispatch(HttpRequest request, CompletableFuture<HttpResponse> vessel) {
            synchronized (monitor) {
                AtomicLong usedCounter = inflight;
                usedCounter.incrementAndGet();
                Cluster usedCluster = delegate;
                usedCluster.dispatch(request, vessel);
                vessel.whenCompleteAsync((__, ___) -> {
                                             synchronized (monitor) {
                                                 if (usedCounter.decrementAndGet() == 0 && usedCluster != delegate) {
                                                     log.log(INFO, "Closing old HTTP client");
                                                     usedCluster.close();
                                                 }
                                             }
                                         },
                                         executor);
            }
        }
Oof, this is an attempt to see if there's a terminal bug in the Jetty client library that sometimes
renders a client instance permanently unusable. If this is the case, replacing the client altogether
should allow the feeder to start working again, when it wouldn't otherwise be able to.
vespa-feed-client/src/main/java/ai/vespa/feed/client/impl/HttpRequestStrategy.java