Andrew Wang created HDFS-5369: --------------------------------- Summary: Support negative caching of user-group mapping Key: HDFS-5369 URL: https://issues.apache.org/jira/browse/HDFS-5369 Project: Hadoop HDFS Issue Type: Improvement Components: namenode Affects Versions: 2.2.0 Reporter: Andrew Wang
We've seen a situation at a couple of our customers where interactions from an unknown user leads to a high-rate of group mapping calls. In one case, this was happening at a rate of 450 calls per second with the shell-based group mapping, enough to severely impact overall namenode performance and also leading to large amounts of log spam (prints a stack trace each time). Let's consider negative caching of group mapping, as well as quashing the rate of this log message. -- This message was sent by Atlassian JIRA (v6.1#6144)