From 7f6811ad73bfc59ca9897804dbe0f8f3a4f84c3c Mon Sep 17 00:00:00 2001 From: Akira Ajisaka Date: Wed, 1 Apr 2015 00:26:16 +0900 Subject: [PATCH] HDFS-7671. hdfs user guide should point to the common rack awareness doc. Contributed by Kai Sasaki. (cherry picked from commit 859cab2f2273f563fd70e3e616758edef91ccf41) --- hadoop-hdfs-project/hadoop-hdfs/CHANGES.txt | 3 +++ .../hadoop-hdfs/src/site/markdown/HdfsUserGuide.md | 2 +- 2 files changed, 4 insertions(+), 1 deletion(-) diff --git a/hadoop-hdfs-project/hadoop-hdfs/CHANGES.txt b/hadoop-hdfs-project/hadoop-hdfs/CHANGES.txt index da3d729a5db..3bfc5504f5a 100644 --- a/hadoop-hdfs-project/hadoop-hdfs/CHANGES.txt +++ b/hadoop-hdfs-project/hadoop-hdfs/CHANGES.txt @@ -53,6 +53,9 @@ Release 2.8.0 - UNRELEASED HDFS-7944. Minor cleanup of BlockPoolManager#getAllNamenodeThreads. (Arpit Agarwal) + HDFS-7671. hdfs user guide should point to the common rack awareness doc. + (Kai Sasaki via aajisaka) + OPTIMIZATIONS BUG FIXES diff --git a/hadoop-hdfs-project/hadoop-hdfs/src/site/markdown/HdfsUserGuide.md b/hadoop-hdfs-project/hadoop-hdfs/src/site/markdown/HdfsUserGuide.md index 37fa4be0099..ffd8532eb6e 100644 --- a/hadoop-hdfs-project/hadoop-hdfs/src/site/markdown/HdfsUserGuide.md +++ b/hadoop-hdfs-project/hadoop-hdfs/src/site/markdown/HdfsUserGuide.md @@ -264,7 +264,7 @@ For command usage, see [balancer](./HDFSCommands.html#balancer). Rack Awareness -------------- -Typically large Hadoop clusters are arranged in racks and network traffic between different nodes with in the same rack is much more desirable than network traffic across the racks. In addition NameNode tries to place replicas of block on multiple racks for improved fault tolerance. Hadoop lets the cluster administrators decide which rack a node belongs to through configuration variable `net.topology.script.file.name`. When this script is configured, each node runs the script to determine its rack id. A default installation assumes all the nodes belong to the same rack. This feature and configuration is further described in PDF attached to [HADOOP-692](https://issues.apache.org/jira/browse/HADOOP-692). +A HDFS cluster can recognize the topology of racks where each nodes are put. It is important to configure this topology in order to optimize the data capacity and usage. For more detail, please check the [rack awareness](../hadoop-common/RackAwareness.html) in common document. Safemode --------