HDFS-16513. [SBN read] Observer Namenode does not trigger the edits rolling of active Namenode

Author: tomscut

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/FSNamesystem.java

@@ -1938,6 +1938,14 @@ public boolean isInStandbyState() {
         HAServiceState.OBSERVER == haContext.getState().getServiceState();
   }
 
+  public boolean isInObserverState() {
+    if (haContext == null || haContext.getState() == null) {
+      return haEnabled;
+    }
+
+    return HAServiceState.OBSERVER == haContext.getState().getServiceState();
+  }
+
   /**
    * return a list of blocks & their locations on {@code datanode} whose
    * total size is {@code size}

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/ha/EditLogTailer.java

@@ -505,7 +505,7 @@ private void doWork() {
           // read any more transactions since the last time a roll was
           // triggered.
           boolean triggeredLogRoll = false;
-          if (tooLongSinceLastLoad() &&
+          if (!namesystem.isInObserverState() && tooLongSinceLastLoad() &&
               lastRollTriggerTxId < lastLoadedTxnId) {
             triggerActiveLogRoll();
             triggeredLogRoll = true;