HDFS-17769. Allows client to actively retry to Active NameNode when the Observer NameNode is too far behind client state id.

Author: gyz-web

hadoop-hdfs-project/hadoop-hdfs/src/main/resources/hdfs-default.xml

@@ -3753,6 +3753,13 @@
   </description>
 </property>
 
+<property>
+  <name>dfs.namenode.observer.too.stale.retry.active.enable</name>
+  <value>false</value>
+  <description>When enabled, allows client to actively retry to Active NameNode when the Observer NameNode is too far behind client state id.
+  </description>
+</property>
+
 <property>
   <name>dfs.namenode.top.windows.minutes</name>
   <value>1,5,25</value>