test

            first_run = false;

            if (!running_ || !pclient_) continue;

            try {

                std::unique_lock<std::timed_mutex> lock;

                if (critical_ || degraded_) {

                    // When degraded/critical, briefly wait to ensure probes can execute

                    lock = std::unique_lock<std::timed_mutex>(client_mutex_, std::chrono::seconds(2));

                } else {

                    // Normal: non-blocking, don't fight session ops

                    lock = std::unique_lock<std::timed_mutex>(client_mutex_, std::try_to_lock);

                }

                // Always use try_to_lock — health probes must never starve

                // session pushes/fetches.  If we can't get the lock, skip

                // this cycle; the next one (3s or 10s later) will retry.

                std::unique_lock<std::timed_mutex> lock(client_mutex_, std::try_to_lock);

                if (!lock.owns_lock()) continue;

                auto health = pclient_->get_cluster_status();

                bool was_degraded = degraded_;