HDFS-7559. Create unit test to automatically compare HDFS related classes and hdfs-default.xml. (Ray Chiang via asuresh)

(cherry picked from commit 3cefc02af7)

hadoop-hdfs-project/hadoop-hdfs/CHANGES.txt

@@ -192,6 +192,9 @@ Release 2.8.0 - UNRELEASED
     HDFS-8207. Improper log message when blockreport interval compared with
     initial delay. (Brahma Reddy Battula and Ashish Singhi via ozawa)
 
+    HDFS-7559. Create unit test to automatically compare HDFS related classes
+    and hdfs-default.xml. (Ray Chiang via asuresh)
+
   OPTIMIZATIONS
 
     HDFS-8026. Trace FSOutputSummer#writeChecksumChunks rather than

hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/tools/TestHdfsConfigFields.java

@@ -0,0 +1,80 @@
+/**
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.apache.hadoop.hdfs.tools;
+
+import java.util.HashSet;
+
+import org.apache.hadoop.conf.TestConfigurationFieldsBase;
+import org.apache.hadoop.hdfs.DFSConfigKeys;
+
+/**
+ * Unit test class to compare the following MR Configuration classes:
+ * <p></p>
+ * {@link org.apache.hadoop.hdfs.DFSConfigKeys}
+ * <p></p>
+ * against hdfs-default.xml for missing properties.  Currently only
+ * throws an error if the class is missing a property.
+ * <p></p>
+ * Refer to {@link org.apache.hadoop.conf.TestConfigurationFieldsBase}
+ * for how this class works.
+ */
+public class TestHdfsConfigFields extends TestConfigurationFieldsBase {
+
+  @Override
+  public void initializeMemberVariables() {
+    xmlFilename = new String("hdfs-default.xml");
+    configurationClasses = new Class[] { DFSConfigKeys.class };
+
+    // Set error modes
+    errorIfMissingConfigProps = true;
+    errorIfMissingXmlProps = false;
+
+    // Allocate
+    xmlPropsToSkipCompare = new HashSet<String>();
+    xmlPrefixToSkipCompare = new HashSet<String>();
+
+    // Used in native code fuse_connect.c
+    xmlPropsToSkipCompare.add("hadoop.fuse.timer.period");
+    xmlPropsToSkipCompare.add("hadoop.fuse.connection.timeout");
+
+    // Used dynamically as part of DFSConfigKeys.DFS_NAMENODE_EDITS_PLUGIN_PREFIX
+    xmlPropsToSkipCompare.add("dfs.namenode.edits.journal-plugin.qjournal");
+
+    // Example (not real) property in hdfs-default.xml
+    xmlPropsToSkipCompare.add("dfs.ha.namenodes.EXAMPLENAMESERVICE");
+
+    // Defined in org.apache.hadoop.fs.CommonConfigurationKeys
+    xmlPropsToSkipCompare.add("hadoop.user.group.metrics.percentiles.intervals");
+
+    // Used oddly by DataNode to create new config String
+    xmlPropsToSkipCompare.add("hadoop.hdfs.configuration.version");
+
+    // Kept in the NfsConfiguration class in the hadoop-hdfs-nfs module
+    xmlPrefixToSkipCompare.add("nfs");
+
+    // Not a hardcoded property.  Used by SaslRpcClient
+    xmlPrefixToSkipCompare.add("dfs.namenode.kerberos.principal.pattern");
+
+    // Skip comparing in branch-2.  Removed in trunk with HDFS-7985.
+    xmlPropsToSkipCompare.add("dfs.webhdfs.enabled");
+
+    // Some properties have moved to HdfsClientConfigKeys
+    xmlPropsToSkipCompare.add("dfs.client.short.circuit.replica.stale.threshold.ms");
+  }
+}