John Ousterhout, a professor of computer science at Stanford, maintains a collection of “Favorite Sayings” grounded in decades of building real systems—RAMCloud, Tcl, and extensive work in distributed systems. These aren’t abstract principles. They’re lessons that apply directly to the work of building, debugging, and shipping software at scale. Optimize After Measurement, Not Before The…
iOS doesn’t expose SOCKS proxy settings in the Settings UI, but it supports Proxy Auto-Config (PAC) files natively. This lets you route iOS traffic through an SSH tunnel on a Linux/Unix host without installing a VPN app. Prerequisites iOS device (iPhone/iPad) on WiFi Linux/Unix host (same network or internet-accessible) with SSH access Web server to…
Jeff Dean’s foundational work on large-scale distributed systems at Google established performance metrics that remain essential for making sound architectural decisions. While absolute numbers shift with hardware advances, the relative orders of magnitude have proven remarkably stable. These latency figures represent the raw cost of fundamental operations. Understanding them prevents decisions that seem reasonable in…
MapReduce is a foundational distributed computing model, but it’s no longer the default choice for new projects. Hadoop’s MapReduce (via YARN in Hadoop 2.x+) remains production-stable and useful for specific scenarios, while Apache Spark, Flink, and cloud-native services handle most modern workloads more efficiently. When MapReduce Still Makes Sense Use MapReduce if you’re: Maintaining existing…
SSH tunneling on Windows routes your traffic through a remote server over an encrypted connection, letting you bypass network restrictions and access resources as if you were on the remote network. The setup creates a SOCKS proxy that listens locally and forwards all traffic through the SSH tunnel. The traffic flow is straightforward: Your application…
cppreference.com is the authoritative resource for C++ language and standard library documentation. It covers all C++ standards from C++98 through C++26 with clear examples and cross-references. Bookmark it as your primary reference. The official C++ standard drafts are available through the C++ standards committee. While final standards require purchase, draft versions and proposals are freely…
The Nokia E71 includes native POP3 and IMAP support without requiring additional messaging apps. This guide covers manual configuration of both protocols with modern best practices. Initial Setup Navigate to Menu → Communic. → Messaging → Options → Settings → E-mail → Options → New mailbox → Start. When prompted “Allow connection?”, select NO. This…
fclose() closes a file stream and disassociates it from its underlying file descriptor. It’s part of the C standard library, defined in <stdio.h>. #include <stdio.h> int fclose(FILE *stream); When called, fclose() flushes buffered output, closes the file descriptor, and deallocates the FILE structure. The function works with both input and output streams. After fclose() returns,…
C allows flexibility in coding style, but discipline matters. Consistent structure makes code readable, maintainable, and less prone to bugs. Here’s a practical approach that scales from small utilities to large projects. One Header Per Source File Pair each source file (.c) with a corresponding header file (.h). The header serves as the module’s public…
Use std::filesystem for all new code. It’s exception-safe, cross-platform, and requires no external dependencies. #include <filesystem> #include <iostream> void ListAllFiles(const char *folderPath) { for (const auto& entry : std::filesystem::recursive_directory_iterator(folderPath)) { std::cout << entry.path() << std::endl; } } To filter by file type, check the entry status: void ListRegularFiles(const char *folderPath) { for (const auto& entry…
Java Applets were obsolete by 2016 and removed from Java 9+. If you need a browser-based system monitoring dashboard, use WebSockets or Server-Sent Events paired with modern JavaScript charting libraries. WebSocket + Python Backend Architecture The most practical setup streams metrics from a Python backend to connected clients using WebSockets. Clients render real-time charts without…
When managing multiple servers, you need reliable ways to verify which hosts are reachable. While orchestration tools like Kubernetes and Ansible handle monitoring at scale, a lightweight Bash script works well for quick spot checks, operational tasks, or smaller deployments. Basic ICMP Reachability Check The simplest approach uses ping to test ICMP reachability: ping -W…
Modern Fedora (29+) uses firewalld by default instead of the legacy iptables service. If you’re working with an older system or one configured for iptables, the concepts here still apply, but you should first check what’s actually managing your firewall: systemctl status firewalld systemctl status iptables If firewalld is active, use firewall-cmd instead. For iptables-based…
If your Linux machine is getting noticeably slower WiFi speeds than other devices on the same network, MTU (Maximum Transmission Unit) misconfiguration can be a culprit. While MTU tuning won’t be the answer in every case, it’s worth investigating if you’re seeing symptoms like high latency, dropped packets, or intermittent connection issues. Understanding MTU MTU…
Xen remains relevant for certain production workloads, particularly in cloud infrastructure (AWS EC2, Citrix Hypervisor) and enterprise environments requiring strong VM isolation. However, most Linux distributions now default to KVM for virtualization due to simpler setup and broader ecosystem support. If you’re evaluating hypervisors, consider KVM or container-based solutions like Podman and Kubernetes for new…
IPv6 is enabled by default on most Linux distributions. While IPv6 adoption has grown, there are legitimate reasons to disable it: some legacy applications don’t handle dual-stack networks well, it can complicate firewall rules, or you might be operating in an environment that doesn’t support it. Disabling IPv6 requires kernel-level configuration through sysctl. Using sysctl…
Network speed varies dramatically across connection types. Here’s a practical breakdown of real-world performance across different technologies, using actual test data and modern measurement approaches. Historical Context and Modern Relevance While 2G and 3G networks are largely deprecated in most developed regions by 2026, understanding their performance characteristics remains relevant for: Legacy system maintenance in…
Fedora has evolved its hostname management over the years. Modern versions use systemd and the /etc/hostname file, while older releases relied on /etc/sysconfig/network. Here’s how to handle both scenarios. Using hostnamectl (Recommended) The most straightforward method on current Fedora is using hostnamectl, which handles hostname changes through systemd: sudo hostnamectl set-hostname newname.example.com For a hostname…
ns (Network Simulator) is a discrete-event simulator used primarily for research and educational purposes in networking. The two major versions—ns-2 and ns-3—are substantially different in architecture and usage patterns. This guide covers installation on current Fedora systems. Installing ns-2 on Fedora Note: ns-2 is legacy software and requires significant compatibility workarounds on modern systems. Consider…
ns-2 reached end-of-life in 2011 and is no longer maintained. If you’re looking to simulate network behavior, you should use ns-3 instead, which is actively developed and provides significantly better accuracy and modern tooling. Why ns-3 Over ns-2 ns-2 was influential in academic networking research, but its architecture has fundamental limitations that became apparent over…