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- 0419 Quoting and word splitting in bash: why “$var” and arrays save you Single quotes, double quotes, no quotes and arrays: how bash splits words and expands globs, and the small set of habits that… Intermediate · Explains an idea · Linux, macOS Article Basics · Shell scripting 15 Oct 2026
- 0374 Alert rules that do not wake you for nothing How to design alerts people trust: alert on symptoms not causes, use for durations, separate page from ticket severities, group and inhibit… Intermediate · Explains an idea · Any system Article Alerting & dashboards 15 Oct 2026
- 0238 Redis persistence and high availability: RDB, AOF, replicas and Sentinel Redis keeps data in memory and writes it to disk with RDB snapshots, an append-only file, or both. Replicas copy data to… Intermediate · Explains an idea · Linux Article Administration & persistence 15 Oct 2026
- 0216 MySQL vs MariaDB: what actually differs MariaDB started as a fork of MySQL and still speaks the same client protocol, but GTIDs, JSON storage, authentication and tooling have… Intermediate · Explains an idea · Linux Article Choosing a database · MySQL & MariaDB 15 Oct 2026
- 0201 pg_hba.conf and PostgreSQL authentication methods pg_hba.conf decides who may connect from where and how they must prove who they are. Rules are checked top to bottom and… Intermediate · Explains an idea · Linux Article Install & connect · Security & access 15 Oct 2026
- 0204 VACUUM, autovacuum and table bloat in PostgreSQL Updates and deletes leave dead row versions behind. VACUUM makes that space reusable, keeps statistics fresh and prevents transaction ID wraparound; autovacuum… Intermediate · Explains an idea · Linux Article Performance & tuning · Roles & administration 15 Oct 2026
- 0170 LVM explained: physical volumes, volume groups and logical volumes LVM puts a flexible layer between disks and filesystems, so you can grow volumes, add disks and take snapshots without repartitioning. Intermediate · Explains an idea · Linux Article Disks, LVM & filesystems 15 Oct 2026
- 0191 Prometheus concepts: pull model, exporters, node_exporter and PromQL basics Prometheus scrapes numeric metrics from your systems over HTTP and stores them as time series. Learn the pull model, metric types, node_exporter,… Intermediate · Explains an idea · Linux Article Prometheus & Grafana 15 Oct 2026
- 0156 Operators, the software catalog (OperatorHub) and OLM on OpenShift Operators automate installing and running software on OpenShift. Learn the difference between cluster Operators and add-on Operators, and how OLM uses catalogs,… Intermediate · Explains an idea · Linux Article Cluster administration · Concepts 15 Oct 2026
- 0102 Proxmox VE storage types: local, LVM-thin, ZFS, NFS and Ceph Proxmox VE stores disks, ISOs, templates and backups in storage pools defined in /etc/pve/storage.cfg. Learn the main storage types, what local and… Intermediate · Explains an idea · Linux Article Disks, LVM & filesystems · Storage 15 Oct 2026
- 0133 Services and Ingress: exposing an app in Kubernetes A Service gives a changing set of Pods one stable address. ClusterIP is internal, NodePort and LoadBalancer reach outside, and an Ingress… Intermediate · Explains an idea · Linux Article Ingress & networking 15 Oct 2026
- 0134 ConfigMaps and Secrets: configuration outside the image ConfigMaps hold plain settings and Secrets hold sensitive values, injected into Pods as environment variables or files. Secrets are only base64-encoded, not… Intermediate · Explains an idea · Linux Article Config, secrets & storage 15 Oct 2026
- 0068 SQL joins explained: INNER, LEFT and finding rows with no match A join combines rows from two tables using a matching condition. INNER JOIN keeps only matches, LEFT JOIN keeps every row from… Intermediate · Explains an idea · Any system Article Joins 15 Oct 2026
- 0069 NULL in SQL: why = NULL never matches and how to handle missing values NULL means "unknown", so comparisons with it are neither true nor false. Use IS NULL, COALESCE and careful aggregates to avoid rows… Intermediate · Explains an idea · Any system Article Queries 15 Oct 2026
- 0086 API authentication basics: API keys, Bearer tokens, and OAuth How APIs know who is calling: static API keys, Bearer tokens in the Authorization header, Basic auth, and a high-level tour of… Intermediate · Explains an idea · Any system Article Authentication 15 Oct 2026
- 0004 Logging instead of print The logging module gives every message a level, a timestamp and a destination you can change without editing code. It is the… Intermediate · Explains an idea · Any system Article Files & automation 15 Oct 2026
- 0018 Promises and async/await explained A promise is a placeholder for a value that arrives later. async/await lets you write code that waits for promises as if… Intermediate · Explains an idea · Any system Article Async code 15 Oct 2026
- 0034 Merging vs rebasing in Git Merge and rebase both bring commits from one branch into another. Merge keeps history exactly as it happened; rebase replays your commits… Intermediate · Explains an idea · Any system Article Branching & rebasing 15 Oct 2026
- 0035 Undoing changes in Git: restore, reset, revert, and reflog Pick the undo command by where the mistake lives: in a file, in the staging area, in a local commit, or in… Intermediate · Explains an idea · Any system Article Undoing changes 15 Oct 2026