DataNode.setNewStorageID pulls entropy from /dev/random -------------------------------------------------------
Key: HDFS-1835 URL: https://issues.apache.org/jira/browse/HDFS-1835 Project: Hadoop HDFS Issue Type: Bug Components: data-node Affects Versions: 0.20.2 Reporter: John Carrino DataNode.setNewStorageID uses SecureRandom.getInstance("SHA1PRNG") which always pulls fresh entropy. It wouldn't be so bad if this were only the 120 bits needed by sha1, but the default impl of SecureRandom actually uses a BufferedInputStream around /dev/random and pulls 1024 bits of entropy for this one call. If you are on a system without much entropy coming in, this call can block and block others. Can we just change this to use "new SecureRandom().nextInt(Integer.MAX_VALUE)" instead? -- This message is automatically generated by JIRA. For more information on JIRA, see: http://www.atlassian.com/software/jira