A reliable, high‑availability website requires a mix of good architecture, proactive monitoring, capacity planning, and fast incident response. Below is a practical, prioritized article that diagnoses the three specific symptoms you listed — not responding host, exhausted storage, and slow user response — and gives concrete prevention and remediation steps you can implement immediately and over time. There are several causes of the problems:
- Not responding host: usually caused by CPU/memory exhaustion, process crashes, network or OS limits, or overloaded firewall/NAT devices.
- Exhausted storage: caused by unbounded logs, backups, user uploads, database growth, or misconfigured retention.
- Slow response for users: caused by overloaded app servers, contention in databases, inefficient queries, cold caches, network latency, or blocking synchronous work.
High level strategy to solve these issues as follow:
- Make outages observable and automated (monitoring + alerting + runbooks).
- Move from single points of failure to distributed, redundant components.
- Separate concerns: scale stateless web tier independently from stateful storage and background processing.
- Protect core services with graceful degradation and backpressure.
But you need to make sure that your organization already have:
- Logging and monitoring system
- Implementation of load balancer
- automatic backup and restore
- having availability sets
- real sizing for the application
- having incident response
immediate Triage Steps (first 0–60 minutes)
- Run health checks
- Verify service health endpoints and orchestrator status (k8s pods, system services, supervisor).
- Check host resource usage: CPU, memory, disk I/O, disk fullness, socket counts.
- Isolate the problem
- If one host is unresponsive, remove it from the load balancer and route traffic to healthy hosts.
- If many hosts show the same symptom, suspect shared dependency (DB, cache, auth, network).
- Free emergency space
- Trim logs older than retention policy, rotate and compress logs, clear temporary directories, and delete orphaned large files.
- If using cloud, attach temporary block storage or increase volume size and resize filesystem.
- Apply short‑term rate limiting
- Apply global request throttles or activate a feature flag to reduce heavy background jobs or nonessential endpoints.
- Communicate
- Post status on status page and notify internal stakeholders with current mitigation actions.
last but not least we need to prepare the architecture and the system better
- Implement centralized monitoring and alerts for disk, CPU, memory, latency, and error rates.
- Move user uploads and logs to scalable object storage; enforce lifecycle and quotas.
- Make web tier stateless and enable autoscaling with health checks.
- Add a CDN for static assets and aggressive caching rules.
- Add request throttling/rate limiting and circuit breakers for heavy endpoints.
- Run profiling to eliminate top 10 slow queries and CPU hotspots.
- Create runbooks and hold incident response drills for the team.