Zero-Downtime Linux Server Fleets: Hardening & Prometheus Telemetry for Game Studios

Linux Kernel Tuning for High Network Throughput

Default Linux kernel settings are tuned for general-purpose workstations, not high-throughput game packet brokers. Before launching game server nodes, configuring `/etc/sysctl.conf` is mandatory:

```ini # Kernel socket buffer and connection backlog tuning net.core.somaxconn = 65535 net.ipv4.tcp_max_syn_backlog = 65535 net.core.netdev_max_backlog = 100000 net.ipv4.tcp_fin_timeout = 15 net.ipv4.tcp_tw_reuse = 1 fs.file-max = 2097152 ```

Prometheus & Alertmanager Hierarchy

Rather than merely monitoring CPU/RAM percentages, game studio metrics focus on: - Active WebSocket socket pool count. - Matchmaker queue wait duration (P95 and P99 percentiles). - Redis command execution latency (alerts triggered if > 15ms). - Database thread pool wait duration.

Zero-Downtime Rolling Restarts With Docker Compose and healthcheck probes connected to an upstream Caddy/Nginx load balancer, we roll out new game server patches node-by-node without dropping a single active match.