Raft is a consensus algorithm designed to be more understandable than alternatives like Paxos. It ensures a cluster of servers can agree on system state even when some nodes fail. The core insight is breaking consensus into independent, manageable subproblems rather than treating it as one complex whole. Core Subproblems Raft splits consensus into three…
A Byzantine Fault occurs when a component in a distributed system behaves unpredictably or maliciously—sending contradictory information to different parts of the system, corrupting data, or deviating entirely from the protocol. The result is potential inconsistency across the network, making consensus impossible without proper safeguards. The term originates from the Byzantine Generals Problem, a thought…
The StoneWall problem is a classic algorithmic challenge that tests your ability to recognize when a stack data structure enables a greedy O(N) solution. The Problem Given an array of wall heights, determine the minimum number of distinct stone blocks needed to construct that height profile. Each stone block can be placed multiple times at…
LevelDB allows key ranges to overlap across SSTables in Level 0, unlike higher levels where overlaps are eliminated through compaction. This design choice is fundamental to LevelDB’s write performance and is worth understanding in detail. Why Level 0 Allows Overlaps The reason comes down to write efficiency. When you write data to LevelDB, it follows…
Listing active services is essential for system monitoring and troubleshooting. Whether you’re investigating a hung process, checking if a daemon started correctly, or auditing what’s actually running on your system, knowing how to query service status quickly saves time. Basic Command The standard way to list running services across all modern Linux distributions is: systemctl…
Blocking JavaScript per-site in Chrome lets you stop intrusive scripts, malicious content, or resource-heavy trackers without disabling JavaScript globally. This gives you surgical control—some sites work fine without JS, while others need it. Access the JavaScript exceptions page Open Chrome and navigate to this URL in the address bar: chrome://settings/contentExceptions#javascript Alternatively, go through the menu:…
Fedora switched to systemd for service management years ago, replacing the traditional /etc/inittab file with a target-based system. While systemctl set-default is the standard approach, understanding the manual method gives you insight into how systemd actually manages boot targets. Systemd Targets vs. Legacy Runlevels Systemd uses targets instead of runlevels. The two primary targets you’ll…
Jeff Dean’s “Designs, Lessons and Advice from Building Large Distributed Systems” is essential reading for anyone building or operating distributed infrastructure. This talk, presented at multiple conferences including LADIS and various tech events, distills decades of experience at Google and now at Google Research. If you’re designing systems that scale beyond a single machine, you…
Historical Archive: This post lists conferences from 2012. The submission deadlines and venues are no longer current. For up-to-date conference information, check the official conference websites or resources like Conference Alert and CCF Deadlines. This post lists important conferences related to Cloud Computing in year 2013. SOSP 2013 SOSP’13: The 24th ACM Symposium on Operating…