HDFS-13964. RBF: TestRouterWebHDFSContractAppend fails with No Active Namenode under nameservice. Contributed by Ayush Saxena.
diff --git a/hadoop-hdfs-project/hadoop-hdfs-rbf/src/test/java/org/apache/hadoop/fs/contract/router/web/RouterWebHDFSContract.java b/hadoop-hdfs-project/hadoop-hdfs-rbf/src/test/java/org/apache/hadoop/fs/contract/router/web/RouterWebHDFSContract.java
index 2f1be52..02e9f39 100644
--- a/hadoop-hdfs-project/hadoop-hdfs-rbf/src/test/java/org/apache/hadoop/fs/contract/router/web/RouterWebHDFSContract.java
+++ b/hadoop-hdfs-project/hadoop-hdfs-rbf/src/test/java/org/apache/hadoop/fs/contract/router/web/RouterWebHDFSContract.java
@@ -82,6 +82,7 @@
           cluster.switchToStandby(ns, NAMENODES[1]);
         }
       }
+      cluster.waitActiveNamespaces();
     } catch (Exception e) {
       cluster = null;
       throw new IOException("Cannot start federated cluster", e);