wangwenli created HADOOP-12529: ---------------------------------- Summary: UserGroupInformation equals method depend on the subject object address Key: HADOOP-12529 URL: https://issues.apache.org/jira/browse/HADOOP-12529 Project: Hadoop Common Issue Type: Bug Components: security Affects Versions: 2.7.1 Reporter: wangwenli
my question is why UserGroupInformation equals method depend on the subject object? try below code which is extract from HiveMetaStore: {code:title=TestUgi.java|borderStyle=solid} UserGroupInformation clientUgi = null; UserGroupInformation clientUgi2 = null; try { clientUgi = UserGroupInformation.createProxyUser("user2", UserGroupInformation.getLoginUser()); clientUgi2 = UserGroupInformation.createProxyUser("user2", UserGroupInformation.getLoginUser()); if (clientUgi.equals(clientUgi2)) { System.out.println("=="); } else { System.out.println("!="); // strangely this will be hit } } catch (IOException e1) { e1.printStackTrace(); } {code} i found that it is because the equal method from UserGroupInformation is compare on subject object ref : subject == ((UserGroupInformation) o).subject; . as you know, ipc.Client connect to namenode, connections.get(ConnectionId) this code will try to reuse the same socket to namenode, but because of ConnectionId's equal depend on ugi equal, which will cause connections.get(ConnectionId) cann't get the same socket, suppose many connect to HiveMetaStore, then many connection to Namenode will established. so my doubts is why UserGroupInformation is compare on subject object ref : subject == ((UserGroupInformation) o).subject, it should compare on subject's principal, am i right? -- This message was sent by Atlassian JIRA (v6.3.4#6332)