private function updateNodes($key, StreamInterface $stream)
    {
        $this->nodeUrls = array_map(function (NodeInfo $element) {
            return $element->getServer();
        }, (new Node($stream, $this->log))->hello());

        $this->log->notice('caching connection info from HELLO', [
            'key' => $key,
            'nodes' => $this->nodeUrls,
            'ttl' => $this->getCacheTtl(),
        ]);

        $this->cache->set($key, $this->nodeUrls, $this->getCacheTtl());
    }