HttpResponse execute(HttpRequest request) throws TimeoutException {
    Stopwatch timer = Stopwatch.createStarted();
    for (int i = 0; i < MAX_RETRIES; i++) {
        if (timer.elapsed(TimeUnit.MILLISECONDS) > REQUEST_TIMEOUT) {
            throw new TimeoutException();
        }
        try {
            return tryExecute(request);
        } catch (ConnectionException e) {
            // cycle one more time
        }
    }
    throw new UnreachableHostException();
}

CompletableFuture<HttpResponse> execute(HttpRequest request, State state) {
    if (state.getTimer().elapsed(TimeUnit.MILLISECONDS) > REQUEST_TIMEOUT) {
        CompletableFuture<HttpResponse> synchronizer = new CompletableFuture<>();
        synchronizer.completeExceptionally(new TimeoutException());
        return synchronizer;
    }
    if (state.getAttempt() >= MAX_ATTEMPTS) {
        CompletableFuture<HttpResponse> synchronizer = new CompletableFuture<>();
        synchronizer.completeExceptionally(new UnreachableHostException());
        return synchronizer;
    }
    return tryExecute(request)
        // о да, мы идем прямо в ад. прошу не обращать
        // внимание на саму сложность конструкции
        .handle((result, throwable) -> {
            if (result != null) {
                return CompletableFuture.completedFuture(result);
            }
            if (throwable instanceof ConnectionException) {
                state.setAttempt(state.getAttempt() + 1);
                return execute(request, state);
            }
            CompletableFuture synchronizer = new CompletableFuture<>();
            synchronizer.completeExceptionally(throwable);
            return synchronizer;
        })
        .thenCompose(f -> f);
}