Tutorials
Cache Stampede in Front of the CDN: Origin Server Loading Wars
Explore the Cache Stampede problem in front of CDNs, its causes, and effective strategies to avoid overloading the origin server.
Tutorials
280 posts
Step-by-step guides, practical examples and hands-on tutorials.
Tutorials
Core Dump Management and Privacy Runbook with systemd-coredump
Collecting core dumps in production: limits, retention, encryption, access and a practical runbook for safe analysis during an incident.
Tutorials
Clock Drift in Distributed Systems: The Hidden Danger of Time
Discover the critical importance of time synchronization in distributed systems and the hidden dangers caused by clock drift. Explore NTP, PTP, logical…
Tutorials
Defense Strategies Against Kubernetes DNS Cache Poisoning
Learn effective defense strategies against DNS cache poisoning attacks in Kubernetes environments. Discover methods to strengthen your security.
Tutorials
Secure Network Device Monitoring with SNMPv3: Auth, Encryption, ACL
A guide to leaving SNMPv2c community strings behind and making network device monitoring secure and operable with SNMPv3 authPriv, views and ACLs.
Tutorials
Kubernetes Pod-to-Pod Network Policies Battles: Securing the Mesh…
Learn step by step how to secure pod-to-pod network communication in Kubernetes with Network Policies. A detailed guide with examples.
Tutorials
Reducing Layer-2 Insider Threats on Switches with DHCP Snooping + DAI
A staged playbook for rolling out DHCP Snooping, DAI, and IP Source Guard on access networks to defend against rogue DHCP, ARP spoofing, and IP impersonation.
Tutorials
PostgreSQL WAL Archiving and a Point-in-Time Recovery Drill
A guide to building PostgreSQL PITR practice with production discipline: WAL archiving, recovery time targets and safe restoration steps.
Tutorials
Kubernetes API Server Audit Log: Policy and SIEM Pipeline
Collecting Kubernetes audit logs without drowning in noise: a practical approach to policy, retention, masking and SIEM correlation.
Tutorials
IPv6-Only Migration with NAT64/DNS64: Runbook and Design
Design, risks, monitoring, and a practical runbook for managing IPv6-only clients' IPv4 dependencies using DNS64 + NAT64.
Tutorials
Service Discovery with Consul: Health Checks and the DNS Interface
A guide to building an operable service discovery layer with Consul through health-driven service registration and the DNS interface.
Tutorials
Centralized Logging with systemd-journal-remote: mTLS and Retention
A practical setup and runbook for shipping journald logs over mTLS to a central collector — without adding agents — while running a disciplined disk budget…
Tutorials
✍️ Hand-written
Self-Healing Services with systemd Watchdog
Reduce 'stuck but not dead' failures with systemd WatchdogSec + notify: unit configuration, restart policy, and alarm integration.
Tutorials
Local Admin Password Rotation with Windows LAPS (AD/Entra)
Cut down lateral movement risk by automatically rotating local admin passwords across servers and clients; build secure operations on top of delegation and…
Tutorials
Designing a Telemetry Pipeline with OpenTelemetry Collector
Treating Collector not just as an agent but as a central telemetry backbone for sampling, redaction, routing and multi-destination delivery.
Tutorials
Linux kdump: Kernel Panic Crash Dump and Triage Runbook
Walks through kdump installation, validation and a sustainable production dump retention flow so you can capture vmcore and triage quickly when a kernel panics.
Tutorials
vSphere/ESXi Host Patch: Maintenance Wave and Rollback Runbook
Manage the ESXi host patch process with ring-based maintenance waves, control capacity/HA risk, and establish safe remediation and rollback discipline.
Tutorials
Packet Capture in Production with tcpdump: A Runbook
Practical tcpdump techniques for collecting minimal-yet-sufficient packet evidence during incidents: filters, snaplen, ring buffer, privacy, and handover…
Tutorials
Zero-Downtime Restart with systemd Socket Activation
A runbook for shrinking deploy impact by separating connection acceptance into a socket unit, so the listening port never drops during service restarts.
Tutorials
Terraform CI Guardrails: Plan/Apply, Drift, and Policy Check
Balancing safety and speed in IaC: a guide to managing prod changes through plan/apply separation, drift detection, policy-as-code, and approval flows.
Tutorials
Golden Image Pipeline with Packer: CIS Baseline and Patch Strategy
A golden image approach that hardens and tests the server image at build-time, accelerating patch, drift and emergency CVE workflows.
Tutorials
PostgreSQL HA: Failover Runbook with Patroni
Walks through quorum, replication lag, switchover/failover testing and recovery steps when running PostgreSQL high availability with Patroni, in runbook form.
Tutorials
Centralized Logging with Windows Event Forwarding (WEF)
Subscriptions, health checks, and a triage runbook to centrally collect and validate security and operations signals in Windows domain environments using WEF.
Tutorials
Linux SoftIRQ Saturation and IRQ Affinity Runbook
Quick triage, measurement and safe tuning steps (ring, queue, IRQ, RPS) under packet drops, high softirq load and ksoftirqd pressure.