Storage Disk

How to Monitor MySQL with Prometheus mysqld_exporter on RHEL 9 — step-by-step RHEL 9 tutorial on Progressive Robot

How to Monitor MySQL with Prometheus mysqld_exporter on RHEL 9

MySQL’s built-in metrics are powerful but not easily scraped. Prometheus mysqld_exporter is the standard exporter that translates MySQL status variables, InnoDB engine metrics, and replication lag statistics into the Prometheus exposition format. Combined with Grafana, the mysqld_exporter provides real-time dashboards covering query throughput, connection pool usage, InnoDB buffer pool hit rates, disk I/O, and replication […]

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How to Install ClickHouse Columnar Database on RHEL 9 — step-by-step RHEL 9 tutorial on Progressive Robot

How to Install ClickHouse Columnar Database on RHEL 9

ClickHouse is a column-oriented database management system (DBMS) designed for Online Analytical Processing (OLAP). Unlike row-oriented databases (MySQL, PostgreSQL) where each row is stored together — efficient for retrieving full records — ClickHouse stores each column separately, making it extremely efficient for aggregation queries that scan specific columns across billions of rows. ClickHouse can process […]

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How to Install Elasticsearch 8 on RHEL 9 — step-by-step RHEL 9 tutorial on Progressive Robot

How to Install Elasticsearch 8 on RHEL 9

Elasticsearch is a distributed, RESTful search and analytics engine built on Apache Lucene. It stores data as JSON documents in indices and provides near-real-time full-text search, log aggregation, metrics analysis, and complex aggregation queries through a simple HTTP/JSON API. Elasticsearch is the core component of the Elastic Stack (ELK Stack) — Elasticsearch stores and searches […]

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How to Install and Configure SQLite on RHEL 9 — step-by-step RHEL 9 tutorial on Progressive Robot

How to Install and Configure SQLite on RHEL 9

SQLite is a self-contained, serverless, zero-configuration SQL database engine that stores an entire database in a single file on disk. Unlike MySQL, PostgreSQL, and MongoDB which require a running server process, SQLite is a library that is linked directly into the application — there is no network connection, no authentication, and no administration overhead. SQLite […]

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How to Install Redis 7 on RHEL 9 — step-by-step RHEL 9 tutorial on Progressive Robot

How to Install Redis 7 on RHEL 9

Redis (Remote Dictionary Server) is an in-memory data structure store used as a cache, session store, real-time leaderboard, pub/sub message broker, and rate-limiting backend. Redis stores all data in RAM with optional disk persistence, making it orders of magnitude faster than relational databases for lookups: sub-millisecond response times at millions of operations per second. Common […]

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How to Configure Nginx WebSocket Proxying on RHEL 9 — step-by-step RHEL 9 tutorial on Progressive Robot

How to Configure Nginx WebSocket Proxying on RHEL 9

WebSockets provide full-duplex communication channels over a single TCP connection, enabling real-time features such as live chat, push notifications, collaborative editing, gaming, and live dashboards. Unlike standard HTTP, which is request-response, WebSocket connections are persistent and bidirectional — the server can push data to clients at any time without a client request. Nginx can act […]

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How to Configure SSL/TLS with OpenSSL and Self-Signed Certificates on RHEL 9 — step-by-step RHEL 9 tutorial on Progressive Robot

How to Configure SSL/TLS with OpenSSL and Self-Signed Certificates on RHEL 9

Even when free trusted certificates from Let’s Encrypt are available for public domains, self-signed certificates serve important roles: development environments, internal network services, IoT devices, automated testing pipelines, and machine-to-machine communication within a private network. Unlike Let’s Encrypt certificates, self-signed certificates require no domain ownership verification or outbound internet access — they can be generated […]

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How to Set Up Varnish Cache as a Reverse Proxy on RHEL 9 — step-by-step RHEL 9 tutorial on Progressive Robot

How to Set Up Varnish Cache as a Reverse Proxy on RHEL 9

Varnish Cache is a high-performance HTTP reverse proxy designed specifically for caching. Unlike Nginx FastCGI cache which caches PHP output files on disk, Varnish stores cached objects entirely in RAM and can serve tens of thousands of requests per second from memory. Varnish operates in front of your web server: it listens on port 80 […]

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How to Configure Nginx FastCGI Caching on RHEL 9 — step-by-step RHEL 9 tutorial on Progressive Robot

How to Configure Nginx FastCGI Caching on RHEL 9

Nginx FastCGI caching stores the output of PHP-FPM (or any FastCGI backend) responses as files on disk and serves them directly without hitting PHP for subsequent requests. For a WordPress site or PHP application serving the same page to many users, this can reduce PHP execution from 200ms to under 1ms and cut server load […]

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How to Install and Configure Caddy Web Server on RHEL 9 — step-by-step RHEL 9 tutorial on Progressive Robot

How to Install and Configure Caddy Web Server on RHEL 9

Caddy is a modern, open-source web server written in Go that stands out for one defining feature: automatic HTTPS. Caddy obtains and renews TLS certificates from Let’s Encrypt or ZeroSSL automatically, with zero configuration required beyond specifying a domain name. It also supports HTTP/2 and HTTP/3 (QUIC) out of the box, and its declarative Caddyfile […]

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