Tsz Wo Nicholas Sze created HDFS-8361: -----------------------------------------
Summary: Choose SSD over DISK in block placement Key: HDFS-8361 URL: https://issues.apache.org/jira/browse/HDFS-8361 Project: Hadoop HDFS Issue Type: Improvement Components: namenode Reporter: Tsz Wo Nicholas Sze Assignee: Tsz Wo Nicholas Sze BlockPlacementPolicyDefault chooses the StorageType by iterating the given StorageType EnumMap in its natural order (the order in which the enum constants are declared). So DISK will be chosen over SSD in One-SSD policy since DISK is declared before SSD as shown below. We should choose SSD first. {code} public enum StorageType { DISK(false), SSD(false), ARCHIVE(false), RAM_DISK(true); ... } {code} -- This message was sent by Atlassian JIRA (v6.3.4#6332)