Fix RequestFailureReason reason codes according to Appache and avoid …

…future conflicts

by assigning new codes to higher numbers

src/java/org/apache/cassandra/exceptions/RequestFailureReason.java

@@ -37,10 +37,12 @@ public enum RequestFailureReason
     READ_TOO_MANY_TOMBSTONES (1),
     TIMEOUT                  (2),
     INCOMPATIBLE_SCHEMA      (3),
-    INDEX_NOT_AVAILABLE      (4),
-    UNKNOWN_COLUMN           (5),
-    UNKNOWN_TABLE            (6),
-    REMOTE_STORAGE_FAILURE   (7);
+    INDEX_NOT_AVAILABLE      (6), // We match it to Apache Cassandra's INDEX_NOT_AVAILABLE code introcued in 5.0
+    // The following codes are not present in Apache Cassandra's RequestFailureReason
+    // We should add new codes in CC (which do not exist in Apache Cassandra) only with big numbers, to avoid conflicts
+    UNKNOWN_COLUMN           (500),
+    UNKNOWN_TABLE            (501),
+    REMOTE_STORAGE_FAILURE   (502);
 
     public static final Serializer serializer = new Serializer();
 

test/unit/org/apache/cassandra/exceptions/RequestFailureReasonTest.java

@@ -0,0 +1,49 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.apache.cassandra.exceptions;
+import org.junit.Test;
+import static org.junit.Assert.assertEquals;
+public class RequestFailureReasonTest
+{
+    private static final RequestFailureReason[] REASONS = RequestFailureReason.values();
+    private static final Object[][] EXPECTED_VALUES =
+    {
+    { 0, "UNKNOWN" },
+    { 1, "READ_TOO_MANY_TOMBSTONES" },
+    { 2, "TIMEOUT" },
+    { 3, "INCOMPATIBLE_SCHEMA" },
+    { 6, "INDEX_NOT_AVAILABLE" },
+    { 500, "UNKNOWN_COLUMN" },
+    { 501, "UNKNOWN_TABLE" },
+    { 502, "REMOTE_STORAGE_FAILURE" }
+    };
+    @Test
+    public void testEnumCodesAndNames()
+    {
+        for (int i = 0; i < REASONS.length; i++)
+        {
+            assertEquals("RequestFailureReason code mismatch for " +
+                         REASONS[i].name(), EXPECTED_VALUES[i][0], REASONS[i].code);
+            assertEquals("RequestFailureReason name mismatch for code " +
+                         REASONS[i].code, EXPECTED_VALUES[i][1], REASONS[i].name());
+        }
+        assertEquals("Number of RequestFailureReason enum constants has changed. Update the test.",
+                     EXPECTED_VALUES.length, REASONS.length);
+    }
+}