# Raft Consensus: What Happens to Client Requests During Leadership Elections? ## Summary In Raft consensus, client requests can only be processed by an elected leader. During leadership elections—triggered by leader failure or network partitions—the cluster cannot service write requests. Requests arriving at this time are **neither processed nor persisted**, causing **client-facing errors** and requiring … Read more
Azure Subscription Disabled After Trial: How to Create Free Resources for Databricks Learning? Summary Azure Free Trials provide 30 days of complimentary access to cloud services. When the trial expires, subscriptions enter a disabled state, preventing resource creation. For learners in data engineering, this blocks essential activities like mounting Azure Data Lake Storage (ADLS Gen2) … Read more
Bash Pitfall: Why true || exit Exits Your Shell (And How To Avoid It) Summary Encountering true || exit causing an immediate shell termination? This unexpected behavior occurs when the command runs in a sourced script context. Despite true succeeding (which should skip the right side of ||), Bash still executes exit and terminates your … Read more
— title: “Solving Terraform Error: Call to function \”merge\” failed: arguments must be maps or objects, got \”tuple\”” date: 2023-09-28 tags: terraform, terraform-aws-eks, aws —  *Learn why Terraform’s merge function fails with “got tuple” error and how to fix it professionally.* ## Problem Summary When merging AWS subnet tags using Terraform’s `merge()` … Read more
Data loss is rarely caused by exotic bugs or Hollywood-style hacker attacks.In the real world, data disappears because of boring, predictable, human-made mistakes—often by experienced teams under pressure.This article breaks down the most common real-world data loss scenarios, based on production incidents, post-mortems, and failure patterns that keep repeating across companies of all sizes.If you … Read more