private static boolean kqueueIsAvailable() {
        boolean available;
        try {
            available = KQueue.isAvailable();
        } catch (NoClassDefFoundError e) {
            LOG.debug("KQueue is unavailable, skipping", e);
            return false;
        } catch (RuntimeException | Error e) {
            LOG.warn("KQueue is unavailable, skipping", e);
            return false;
        }
        if (!available) {
            LOG.debug("KQueue is unavailable, skipping", KQueue.unavailabilityCause());
        }
        return available;
    }
Keys should be a short string usable in metrics.
zuul-core/src/main/java/com/netflix/zuul/netty/server/Server.java