From 9c680d0b0508934b9b000ece84f25988272e901f Mon Sep 17 00:00:00 2001 From: Akira Ajisaka Date: Thu, 27 Oct 2016 16:30:57 +0900 Subject: [PATCH] HDFS-11049. The description of dfs.block.replicator.classname is not clear. Contributed by Yiqun Lin. --- .../hadoop-hdfs/src/main/resources/hdfs-default.xml | 11 +++++++++++ 1 file changed, 11 insertions(+) diff --git a/hadoop-hdfs-project/hadoop-hdfs/src/main/resources/hdfs-default.xml b/hadoop-hdfs-project/hadoop-hdfs/src/main/resources/hdfs-default.xml index 61a706309af..061d07869cf 100644 --- a/hadoop-hdfs-project/hadoop-hdfs/src/main/resources/hdfs-default.xml +++ b/hadoop-hdfs-project/hadoop-hdfs/src/main/resources/hdfs-default.xml @@ -3272,6 +3272,17 @@ org.apache.hadoop.hdfs.server.blockmanagement.BlockPlacementPolicyDefault Class representing block placement policy for non-striped files. + There are four block placement policies currently being supported: + BlockPlacementPolicyDefault, BlockPlacementPolicyWithNodeGroup, + BlockPlacementPolicyRackFaultTolerant and BlockPlacementPolicyWithUpgradeDomain. + BlockPlacementPolicyDefault chooses the desired number of targets + for placing block replicas in a default way. BlockPlacementPolicyWithNodeGroup + places block replicas on environment with node-group layer. BlockPlacementPolicyRackFaultTolerant + places the replicas to more racks. + BlockPlacementPolicyWithUpgradeDomain places block replicas that honors upgrade domain policy. + The details of placing replicas are documented in the javadoc of the corresponding policy classes. + The default policy is BlockPlacementPolicyDefault, and the corresponding class is + org.apache.hadoop.hdfs.server.blockmanagement.BlockPlacementPolicyDefault.