Performance

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to prevent XSS, clickjacking, and MIME sniffing attacks; enforcing TLS 1.3 and strong cipher suites to eliminate outdated protocol vulnerabilities; enabling OCSP Stapling so clients can verify certificate validity without a round-trip […]

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Common Problems 114137

RHEL 10 tuned Profile Change Causes Latency Spikes

🟡 Medium   ⏱ 5–30 min  Last verified: 10 November 2025 Affected versions: RHEL 10.0 RHEL 10.1 📖 ~1 min read Table of contents Symptom & Impact Environment & Reproduction Root Cause Analysis Quick Triage Step-by-Step Diagnosis Solution – Primary Fix Solution – Alternative Approaches Verification & Acceptance Criteria Rollback Plan Prevention & Hardening Related […]

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

How to Install and Configure OpenLiteSpeed Web Server on RHEL 9

OpenLiteSpeed (OLS) is the open-source version of LiteSpeed Web Server — one of the highest-performance HTTP servers available, purpose-built for serving PHP applications. OpenLiteSpeed uses an event-driven architecture similar to Nginx but includes a built-in PHP engine (LSAPI) that processes PHP requests 3–5x faster than PHP-FPM behind Nginx, eliminating the socket overhead of the FastCGI […]

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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 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 Enable Brotli and Gzip Compression in Nginx on RHEL 9 — step-by-step RHEL 9 tutorial on Progressive Robot

How to Enable Brotli and Gzip Compression in Nginx on RHEL 9

Text-based HTTP responses — HTML, CSS, JavaScript, JSON, XML, SVG — compress dramatically with standard compression algorithms, often achieving 60–80% size reduction. Nginx supports two compression algorithms: gzip (built-in, universal browser support) and Brotli (via the ngx_brotli dynamic module, 15–20% better compression than gzip for text, supported by all modern browsers). Enabling compression is one […]

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How to Set Up SLES 16 for High-Performance Computing — step-by-step SUSE Linux Enterprise 16 tutorial on Progressive Robot

How to Set Up SLES 16 for High-Performance Computing

Introduction This tutorial covers How to Set Up SLES 16 for High-Performance Computing on SLES 16. SLES 16 (SUSE Linux Enterprise Server 16) is SUSE’s enterprise-grade Linux distribution. It uses the zypper package manager, AppArmor for mandatory access control, and systemctl for service management. Prerequisites Ensure your SLES 16 system is up to date: zypper […]

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How to Configure Nginx Load Balancing (Round-Robin, Least Conn) on RHEL 9 — step-by-step RHEL 9 tutorial on Progressive Robot

How to Configure Nginx Load Balancing (Round-Robin, Least Conn) on RHEL 9

Load balancing distributes incoming requests across multiple backend servers, preventing any single server from becoming a bottleneck and providing horizontal scalability and fault tolerance. Nginx supports four load balancing methods natively: round-robin (the default), least connections, IP hash (session persistence), and weight-based. The upstream block defines the pool of backend servers and their weights, and […]

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How to Enable HTTP/2 with Nginx on RHEL 9 — step-by-step RHEL 9 tutorial on Progressive Robot

How to Enable HTTP/2 with Nginx on RHEL 9

HTTP/2 is the second major version of the HTTP protocol, standardised in 2015, and offers significant performance improvements over HTTP/1.1: header compression (HPACK), multiplexing (multiple requests over a single connection), server push, and binary framing. On a typical webpage with dozens of assets (CSS, JavaScript, images, fonts), HTTP/2 multiplexing eliminates the head-of-line blocking that forces […]

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