Weekly Knowledge Summary: Yarn Resource Scheduler, Hadoop Rack Awareness, HDFS Data Flow, and Small File Solutions

From: Wang Zhiwu To: Friends

This week, after the Qingming holiday, performance reviews have been completed, leaving more mental space for reflection despite a busy schedule.

Yesterday I attended a live internal broadcast by Teacher Ma, who addressed hot topics such as the 996 overtime issue and future industry trends; I will share my own thoughts later.

Our group chat has become increasingly active, with many members asking technical and learning questions. I apologize for delayed replies due to heavy workload, and encourage everyone to continue sharing knowledge and interview experiences within the group.

Weekly Knowledge Points

01 Yarn Resource Scheduling System

This article introduces the background, architecture, and principles of Yarn, recommending the CDH 2.7.x version for production environments and promising further curated resources.

02 Hadoop Rack Awareness

HDFS uses a rack‑aware strategy to improve reliability, availability, and network bandwidth utilization. The NameNode determines each DataNode's rack ID via the NetworkTopology data structure.

03 HDFS Data Flow

This section explains the read/write process of HDFS, a common interview topic.

04 HDFS Small‑File Problem Solutions

The small‑file issue is frequent in clusters; two articles are shared to address it:

https://dwz.cn/M4GpAe6e

https://dwz.cn/2ij0hqcE

Next Week's Work Plan

The upcoming May 1st holiday will be a relaxed period, but knowledge sharing continues with two upcoming articles on thinking and growth, as well as discussions on national trends such as city‑level household registration reforms and talent policies.

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