Practicing data-driven principles and believing technology can change the world.
This guide explains why HDFS enters safe mode after a DataNode failure, describes the safe‑mode state and its exit conditions, and provides step‑by‑step commands and troubleshooting procedures to analyze, fix, and recover from safe‑mode incidents in Hadoop clusters.
A high‑load Kubernetes node entered NotReady due to repeated OOM‑killer activity, daemonset restarts, and PLEG health failures, and the article walks through diagnosis, log analysis, root‑cause explanation, and practical remediation steps to restore node readiness.
This article examines the growing demand for real‑time data warehouses, compares mature streaming frameworks, evaluates Lambda, Kappa and hybrid architectures, reviews industry implementations from Didi and OPPO, and proposes a standard‑layer + stream + data‑lake solution with Apache Paimon, Hudi, and Iceberg.
This article explains the motivations for moving a Java 8 project to JDK 11, compares JDK 11 and JDK 17, outlines JDK 11’s key features, details Tomcat 8.5 differences, provides step‑by‑step migration instructions, and shares troubleshooting tips for common upgrade issues.
This article explains how to optimize Flink’s RocksDB state backend for large‑scale streaming jobs, covering state types, enabling latency tracking, incremental checkpoints, predefined options, and advanced memory and thread settings, with practical configuration examples and performance comparisons.
This guide explains the GPT‑2 background, required software, environment configuration, code modifications for TensorFlow 2.x, data download, execution commands, and sample test results, providing a full step‑by‑step process for local deployment of the model.
This article details the background of a Flink 1.10 cluster on Huawei Cloud, the technical challenges that prompted an upgrade, a step‑by‑step migration plan to Flink 1.14.6, troubleshooting of frequent errors, precautionary measures, and the performance and operational benefits achieved after the upgrade.
The article explains how null or empty query values caused MongoDB to ignore the intended index, leading to massive slow queries and service timeouts, and details the step‑by‑step investigation, plan‑cache invalidation, and the corrective addition of a compound index that restored normal performance.
