YARN-9789. Disable Option for Write Ahead Logs of LogMutation. Contributed by Prabhu Joseph

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/main/java/org/apache/hadoop/yarn/server/resourcemanager/scheduler/capacity/conf/LeveldbConfigurationStore.java

@@ -224,12 +224,14 @@ public void close() throws IOException {
 
   @Override
   public void logMutation(LogMutation logMutation) throws IOException {
-    LinkedList<LogMutation> logs = deserLogMutations(db.get(bytes(LOG_KEY)));
+    if (maxLogs > 0) {
-    logs.add(logMutation);
+      LinkedList<LogMutation> logs = deserLogMutations(db.get(bytes(LOG_KEY)));
-    if (logs.size() > maxLogs) {
+      logs.add(logMutation);
-      logs.removeFirst();
+      if (logs.size() > maxLogs) {
+        logs.removeFirst();
+      }
+      db.put(bytes(LOG_KEY), serLogMutations(logs));
     }
-    db.put(bytes(LOG_KEY), serLogMutations(logs));
     pendingMutation = logMutation;
   }
 
@@ -337,6 +339,11 @@ protected LinkedList<LogMutation> getLogs() throws Exception {
     return deserLogMutations(db.get(bytes(LOG_KEY)));
   }
 
+  @VisibleForTesting
+  protected DB getDB() {
+    return db;
+  }
+
   @Override
   public void storeVersion() throws Exception {
     String key = VERSION_KEY;

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/main/java/org/apache/hadoop/yarn/server/resourcemanager/scheduler/capacity/conf/ZKConfigurationStore.java

@@ -162,17 +162,19 @@ public synchronized void storeVersion() throws Exception {
 
   @Override
   public void logMutation(LogMutation logMutation) throws Exception {
-    byte[] storedLogs = zkManager.getData(logsPath);
+    if (maxLogs > 0) {
-    LinkedList<LogMutation> logs = new LinkedList<>();
+      byte[] storedLogs = zkManager.getData(logsPath);
-    if (storedLogs != null) {
+      LinkedList<LogMutation> logs = new LinkedList<>();
-      logs = (LinkedList<LogMutation>) deserializeObject(storedLogs);
+      if (storedLogs != null) {
+        logs = (LinkedList<LogMutation>) deserializeObject(storedLogs);
+      }
+      logs.add(logMutation);
+      if (logs.size() > maxLogs) {
+        logs.remove(logs.removeFirst());
+      }
+      zkManager.safeSetData(logsPath, serializeObject(logs), -1, zkAcl,
+              fencingNodePath);
     }
-    logs.add(logMutation);
-    if (logs.size() > maxLogs) {
-      logs.remove(logs.removeFirst());
-    }
-    zkManager.safeSetData(logsPath, serializeObject(logs), -1, zkAcl,
-        fencingNodePath);
     pendingMutation = logMutation;
   }
 

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/test/java/org/apache/hadoop/yarn/server/resourcemanager/scheduler/capacity/conf/TestLeveldbConfigurationStore.java

@@ -31,13 +31,17 @@
 import org.apache.hadoop.yarn.webapp.dao.SchedConfUpdateInfo;
 import org.junit.Before;
 import org.junit.Test;
+import org.iq80.leveldb.DB;
+import org.iq80.leveldb.DBIterator;
 
 import java.io.File;
+import java.nio.charset.StandardCharsets;
 import java.util.HashMap;
 import java.util.LinkedList;
 import java.util.Map;
 
 import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertFalse;
 import static org.junit.Assert.assertNull;
 
 /**
@@ -112,6 +116,33 @@ public void testPersistUpdatedConfiguration() throws Exception {
     confStore.close();
   }
 
+  @Test
+  public void testDisableAuditLogs() throws Exception {
+    conf.setLong(YarnConfiguration.RM_SCHEDCONF_MAX_LOGS, 0);
+    confStore.initialize(conf, schedConf, rmContext);
+
+    Map<String, String> update = new HashMap<>();
+    update.put("key1", "val1");
+    YarnConfigurationStore.LogMutation mutation =
+        new YarnConfigurationStore.LogMutation(update, TEST_USER);
+    confStore.logMutation(mutation);
+
+    boolean logKeyPresent = false;
+    DB db = ((LeveldbConfigurationStore) confStore).getDB();
+    DBIterator itr = db.iterator();
+    itr.seekToFirst();
+    while (itr.hasNext()) {
+      Map.Entry<byte[], byte[]> entry = itr.next();
+      String key = new String(entry.getKey(), StandardCharsets.UTF_8);
+      if (key.equals("log")) {
+        logKeyPresent = true;
+        break;
+      }
+    }
+    assertFalse("Audit Log is not disabled", logKeyPresent);
+    confStore.close();
+  }
+
   @Test
   public void testMaxLogs() throws Exception {
     conf.setLong(YarnConfiguration.RM_SCHEDCONF_MAX_LOGS, 2);

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/test/java/org/apache/hadoop/yarn/server/resourcemanager/scheduler/capacity/conf/TestZKConfigurationStore.java

@@ -18,6 +18,7 @@
 
 package org.apache.hadoop.yarn.server.resourcemanager.scheduler.capacity.conf;
 
+import org.apache.hadoop.util.curator.ZKCuratorManager;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 import org.apache.curator.framework.CuratorFramework;
@@ -221,6 +222,28 @@ public void testMaxLogs() throws Exception {
     assertEquals("val3", logs.get(1).getUpdates().get("key3"));
   }
 
+
+  @Test
+  public void testDisableAuditLogs() throws Exception {
+    conf.setLong(YarnConfiguration.RM_SCHEDCONF_MAX_LOGS, 0);
+    confStore.initialize(conf, schedConf, rmContext);
+    String znodeParentPath = conf.get(YarnConfiguration.
+        RM_SCHEDCONF_STORE_ZK_PARENT_PATH,
+        YarnConfiguration.DEFAULT_RM_SCHEDCONF_STORE_ZK_PARENT_PATH);
+    String logsPath = ZKCuratorManager.getNodePath(znodeParentPath, "LOGS");
+    byte[] data = null;
+    ((ZKConfigurationStore) confStore).zkManager.setData(logsPath, data, -1);
+
+    Map<String, String> update = new HashMap<>();
+    update.put("key1", "val1");
+    YarnConfigurationStore.LogMutation mutation =
+        new YarnConfigurationStore.LogMutation(update, TEST_USER);
+    confStore.logMutation(mutation);
+
+    data = ((ZKConfigurationStore) confStore).zkManager.getData(logsPath);
+    assertNull("Failed to Disable Audit Logs", data);
+  }
+
   public Configuration createRMHAConf(String rmIds, String rmId,
       int adminPort) {
     Configuration conf = new YarnConfiguration();