NPE may occur when opening master-status or table.jsp or procedure.jsp while Master is initializing

Author: guluo2016

hbase-server/src/main/java/org/apache/hadoop/hbase/master/http/MasterStatusServlet.java

@@ -77,7 +77,10 @@ public void doGet(HttpServletRequest request, HttpServletResponse response) thro
   private ServerName getMetaLocationOrNull(HMaster master) {
     RegionStateNode rsn = master.getAssignmentManager().getRegionStates()
       .getRegionStateNode(RegionInfoBuilder.FIRST_META_REGIONINFO);
-    return rsn.isInState(RegionState.State.OPEN) ? rsn.getRegionLocation() : null;
+    if (rsn != null) {
+      return rsn.isInState(RegionState.State.OPEN) ? rsn.getRegionLocation() : null;
+    }
+    return null;
   }
 
   private Map<String, Integer> getFragmentationInfo(HMaster master, Configuration conf)

hbase-server/src/main/resources/hbase-webapps/master/procedures.jsp

@@ -47,8 +47,28 @@
 <%@ page import="org.apache.hadoop.hbase.metrics.Histogram" %>
 <%@ page import="java.util.TreeMap" %>
 <%@ page import="org.apache.hadoop.hbase.metrics.impl.HistogramImpl" %>
+
+<jsp:include page="header.jsp">
+    <jsp:param name="pageTitle" value="${pageTitle}"/>
+</jsp:include>
+
 <%
   HMaster master = (HMaster) getServletContext().getAttribute(HMaster.MASTER);
+  if (!master.isInitialized()) {
+%>
+    <div class="container-fluid content">
+      <div class="row inner_header">
+        <div class="page-header">
+          <h1>Master is initializing</h1>
+        </div>
+      </div>
+      <p><hr><p>
+      <jsp:include page="redirect.jsp" />
+    </div>
+<%  return;
+  } %>
+
+<%
   ProcedureExecutor<MasterProcedureEnv> procExecutor = master.getMasterProcedureExecutor();
   List<Procedure<MasterProcedureEnv>> procedures = procExecutor.getProcedures();
   Collections.sort(procedures, new Comparator<Procedure>() {
@@ -63,9 +83,6 @@
   List<LockedResource> lockedResources = master.getLocks();
   pageContext.setAttribute("pageTitle", "HBase Master Procedures: " + master.getServerName());
 %>
-<jsp:include page="header.jsp">
-    <jsp:param name="pageTitle" value="${pageTitle}"/>
-</jsp:include>
 
 <div class="container-fluid content">
   <div class="row top_header">

hbase-server/src/main/resources/hbase-webapps/master/table.jsp

@@ -148,11 +148,32 @@
     return "";
   }
 %>
+
+<jsp:include page="header.jsp">
+  <jsp:param name="pageTitle" value="${pageTitle}"/>
+</jsp:include>
+
 <%
   final String ZEROMB = "0 MB";
   HMaster master = (HMaster)getServletContext().getAttribute(HMaster.MASTER);
   Configuration conf = master.getConfiguration();
   String fqtn = request.getParameter("name");
+  // handle the case for fqtn is null or master is not initialized with error message + redirect
+  if (fqtn == null || !master.isInitialized()) {
+%>
+    <div class="container-fluid content">
+      <div class="row inner_header">
+        <div class="page-header">
+          <h1>Table not ready</h1>
+        </div>
+      </div>
+      <p><hr><p>
+      <jsp:include page="redirect.jsp" />
+    </div>
+<%  return;
+  } %>
+
+<%
   final String escaped_fqtn = StringEscapeUtils.escapeHtml4(fqtn);
   Table table = master.getConnection().getTable(TableName.valueOf(fqtn));
   boolean showFragmentation = conf.getBoolean("hbase.master.ui.fragmentation.enabled", false);
@@ -201,24 +222,6 @@
   final MetaBrowser metaBrowser = new MetaBrowser(connection, request);
 %>
 
-<jsp:include page="header.jsp">
-  <jsp:param name="pageTitle" value="${pageTitle}"/>
-</jsp:include>
-
-<% // handle the case for fqtn is null or master is not initialized with error message + redirect
-  if (fqtn == null || ! master.isInitialized()) { %>
-    <div class="container-fluid content">
-      <div class="row inner_header">
-        <div class="page-header">
-          <h1>Table not ready</h1>
-        </div>
-      </div>
-      <p><hr><p>
-      <jsp:include page="redirect.jsp" />
-    </div>
-<%  return;
-  } %>
-
 <% // unknow table
   if (! admin.tableExists(TableName.valueOf(fqtn)).get()) { %>
     <div class="container-fluid content">