DNS

How to Configure Redis Cluster and Sentinel on RHEL 9 — step-by-step RHEL 9 tutorial on Progressive Robot

How to Configure Redis Cluster and Sentinel on RHEL 9

A single Redis instance has two failure modes: if the server goes down, all cached data is lost and every request hits the origin database; and if the dataset grows beyond a single server’s RAM, there’s no built-in way to distribute it. Redis provides two solutions: Redis Sentinel for high availability (automatic failover with a […]

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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 Secure MySQL: Remove Root Remote Login, audit_log on RHEL 9 — step-by-step RHEL 9 tutorial on Progressive Robot

How to Secure MySQL: Remove Root Remote Login, audit_log on RHEL 9

A default MySQL installation has several security weaknesses: a root account that may be accessible remotely, anonymous user accounts, a test database anyone can access, and no audit logging of who accessed what data. Securing MySQL is essential before any production deployment and covers four main areas: access control (who can connect from where), authentication […]

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How to Harden Nginx: Security Headers, TLS 1.3, OCSP Stapling on RHEL 9 — step-by-step RHEL 9 tutorial on Progressive Robot

How to Harden Nginx: Security Headers, TLS 1.3, OCSP Stapling on RHEL 9

A default Nginx installation serves content, but many security hardening steps are not enabled by default. Hardening Nginx means configuring HTTP security headers to prevent XSS, clickjacking, and MIME sniffing attacks; enforcing TLS 1.3 and strong cipher suites to eliminate outdated protocol vulnerabilities; enabling OCSP Stapling so clients can verify certificate validity without a round-trip […]

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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 Configure HAProxy for HTTP and TCP Load Balancing on RHEL 9 — step-by-step RHEL 9 tutorial on Progressive Robot

How to Configure HAProxy for HTTP and TCP Load Balancing on RHEL 9

HAProxy (High Availability Proxy) is a battle-hardened open-source load balancer and proxy for TCP and HTTP workloads. Where Nginx load balancing is sufficient for simple round-robin HTTP distribution, HAProxy provides a richer feature set: advanced health checks with multiple failure thresholds, ACL-based routing, Layer 4 TCP load balancing for non-HTTP protocols (MySQL, Redis, SMTP), detailed […]

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How to Configure Nginx Rate Limiting and Connection Throttling on RHEL 9 — step-by-step RHEL 9 tutorial on Progressive Robot

How to Configure Nginx Rate Limiting and Connection Throttling on RHEL 9

Rate limiting is a server-side defence that restricts how many requests a client can make within a time window. Without rate limiting, a single IP address or bot can flood your server with thousands of requests per second — crashing your application, exhausting your database connection pool, or triggering denial-of-service conditions. Nginx provides two rate […]

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How to Set Up ModSecurity WAF with Apache on RHEL 9 — step-by-step RHEL 9 tutorial on Progressive Robot

How to Set Up ModSecurity WAF with Apache on RHEL 9

ModSecurity is the leading open-source Web Application Firewall (WAF), capable of inspecting all HTTP requests and responses against a ruleset and blocking malicious traffic including SQL injection, cross-site scripting (XSS), remote file inclusion, and OWASP Top 10 attack patterns. Combined with the OWASP Core Rule Set (CRS), ModSecurity transforms Apache into a security gateway that […]

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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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How to Secure Apache with Let's Encrypt and Certbot on RHEL 9 — step-by-step RHEL 9 tutorial on Progressive Robot

How to Secure Apache with Let’s Encrypt and Certbot on RHEL 9

Like Nginx, Apache can be secured with free SSL/TLS certificates from Let’s Encrypt using Certbot. The python3-certbot-apache plugin performs domain validation, obtains the certificate, and automatically updates your Apache virtual host configuration with the SSL directives, HTTP-to-HTTPS redirect, and modern cipher settings. This guide covers installing Certbot on RHEL 9, obtaining a certificate for your […]

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