Return both read and route endpoints in shuffled order.

enterprise/causal-clustering/src/main/java/org/neo4j/causalclustering/discovery/procedures/GetServersProcedure.java

@@ -117,10 +117,7 @@ private List<ReadWriteRouteEndPoint> routeEndpoints()
 
     private List<ReadWriteRouteEndPoint> writeEndpoints( AdvertisedSocketAddress leader )
     {
-        List<ReadWriteRouteEndPoint> writeEndPoints =
-                Stream.of( leader ).map( ReadWriteRouteEndPoint::write ).collect( Collectors.toList() );
-        Collections.shuffle( writeEndPoints );
-        return writeEndPoints;
+        return Stream.of( leader ).map( ReadWriteRouteEndPoint::write ).collect( Collectors.toList() );
 
     }
 

enterprise/causal-clustering/src/test/java/org/neo4j/causalclustering/discovery/procedures/GetServersProcedureRoutingTest.java

@@ -0,0 +1,118 @@
+/*
+ * Copyright (c) 2002-2016 "Neo Technology,"
+ * Network Engine for Objects in Lund AB [http://neotechnology.com]
+ *
+ * This file is part of Neo4j.
+ *
+ * Neo4j is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as
+ * published by the Free Software Foundation, either version 3 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+package org.neo4j.causalclustering.discovery.procedures;
+
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.junit.runners.Parameterized;
+import org.junit.runners.Parameterized.Parameter;
+
+import java.util.Arrays;
+import java.util.Collection;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.UUID;
+
+import org.neo4j.causalclustering.core.consensus.LeaderLocator;
+import org.neo4j.causalclustering.discovery.CoreAddresses;
+import org.neo4j.causalclustering.discovery.CoreTopology;
+import org.neo4j.causalclustering.discovery.CoreTopologyService;
+import org.neo4j.causalclustering.discovery.ReadReplicaTopology;
+import org.neo4j.causalclustering.identity.ClusterId;
+import org.neo4j.causalclustering.identity.MemberId;
+import org.neo4j.kernel.configuration.Config;
+
+import static java.util.Collections.emptySet;
+import static org.junit.Assert.assertFalse;
+import static org.junit.runners.Parameterized.Parameters;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.when;
+import static org.neo4j.causalclustering.discovery.procedures.GetServersProcedureTest.coreAddresses;
+import static org.neo4j.causalclustering.identity.RaftTestMember.member;
+import static org.neo4j.helpers.collection.Iterators.asList;
+import static org.neo4j.logging.NullLogProvider.getInstance;
+
+@RunWith( Parameterized.class )
+public class GetServersProcedureRoutingTest
+{
+    @Parameters
+    public static Collection<Object> data()
+    {
+        return Arrays.asList( 1, 2 );
+    } //the write endpoints are always index 0
+
+    @Parameter
+    public int serverClass;
+
+    private ClusterId clusterId = new ClusterId( UUID.randomUUID() );
+    private Config config = Config.defaults();
+
+    @Test
+    public void shouldReturnEndpointsInDifferentOrders() throws Exception
+    {
+        // given
+        final CoreTopologyService coreTopologyService = mock( CoreTopologyService.class );
+
+        LeaderLocator leaderLocator = mock( LeaderLocator.class );
+        when( leaderLocator.getLeader() ).thenReturn( member( 0 ) );
+
+        Map<MemberId,CoreAddresses> coreMembers = new HashMap<>();
+        coreMembers.put( member( 0 ), coreAddresses( 0 ) );
+        coreMembers.put( member( 1 ), coreAddresses( 1 ) );
+        coreMembers.put( member( 2 ), coreAddresses( 2 ) );
+
+        final CoreTopology clusterTopology = new CoreTopology( clusterId, false, coreMembers );
+        when( coreTopologyService.coreServers() ).thenReturn( clusterTopology );
+        when( coreTopologyService.readReplicas() ).thenReturn( new ReadReplicaTopology( clusterId, emptySet() ) );
+
+        final GetServersProcedure proc =
+                new GetServersProcedure( coreTopologyService, leaderLocator, config, getInstance() );
+
+        // when
+        Object[] endpoints = getEndpoints( proc );
+
+        //then
+        Object[] endpointsInDifferentOrder = getEndpoints( proc );
+        for ( int i = 0; i < 100; i++ )
+        {
+            if ( Arrays.deepEquals( endpointsInDifferentOrder, endpoints ) )
+            {
+                endpointsInDifferentOrder = getEndpoints( proc );
+            }
+            else
+            {
+                //Different order of servers, no need to retry.
+                break;
+            }
+        }
+        assertFalse( Arrays.deepEquals( endpoints, endpointsInDifferentOrder ) );
+    }
+
+    private Object[] getEndpoints( GetServersProcedure proc )
+            throws org.neo4j.kernel.api.exceptions.ProcedureException
+    {
+        List<Object[]> results = asList( proc.apply( null, new Object[0] ) );
+        Object[] rows = results.get( 0 );
+        List<Map<String,Object[]>> servers = (List<Map<String,Object[]>>) rows[1];
+        Map<String,Object[]> endpoints = servers.get( serverClass );
+        return endpoints.get( "addresses" );
+    }
+}

enterprise/causal-clustering/src/test/java/org/neo4j/causalclustering/discovery/procedures/GetServersProcedureTest.java

@@ -422,57 +422,6 @@ public void shouldReturnNoWriteEndpointsIfThereIsNoAddressForTheLeader() throws
                 containsInAnyOrder( coreAddresses( 0 ).getRaftServer().toString() ) );
     }
 
-    @Test
-    public void shouldReturnReadEndpointsInDifferentOrders() throws Exception
-    {
-        // given
-        final CoreTopologyService coreTopologyService = mock( CoreTopologyService.class );
-
-        LeaderLocator leaderLocator = mock( LeaderLocator.class );
-        when( leaderLocator.getLeader() ).thenReturn( member( 0 ) );
-
-        Map<MemberId,CoreAddresses> coreMembers = new HashMap<>();
-        coreMembers.put( member( 0 ), coreAddresses( 0 ) );
-        coreMembers.put( member( 1 ), coreAddresses( 1 ) );
-        coreMembers.put( member( 2 ), coreAddresses( 2 ) );
-
-        final CoreTopology clusterTopology = new CoreTopology( clusterId, false, coreMembers );
-        when( coreTopologyService.coreServers() ).thenReturn( clusterTopology );
-        when( coreTopologyService.edgeServers() ).thenReturn( new EdgeTopology( clusterId, emptySet() ) );
-
-        final GetServersProcedure proc =
-                new GetServersProcedure( coreTopologyService, leaderLocator, config, getInstance() );
-
-        // when
-        Object[] readServers = getReadServers( proc );
-
-        //then
-        Object[] readServersDifferentOrder = getReadServers( proc );
-        for ( int i = 0; i < 100; i++ )
-        {
-            if ( Arrays.deepEquals( readServersDifferentOrder, readServers ) )
-            {
-                readServersDifferentOrder = getReadServers( proc );
-            }
-            else
-            {
-                //Different order of servers, no need to retry.
-                break;
-            }
-        }
-        assertFalse( Arrays.deepEquals( readServers, readServersDifferentOrder ) );
-    }
-
-    private Object[] getReadServers( GetServersProcedure proc )
-            throws org.neo4j.kernel.api.exceptions.ProcedureException
-    {
-        List<Object[]> results = asList( proc.apply( null, new Object[0] ) );
-        Object[] rows = results.get( 0 );
-        List<Map<String,Object[]>> servers = (List<Map<String,Object[]>>) rows[1];
-        Map<String,Object[]> readServers = servers.get( 1 );
-        return readServers.get( "addresses" );
-    }
-
     static Set<ReadReplicaAddresses> addresses( int... ids )
     {
         return Arrays.stream( ids ).mapToObj( GetServersProcedureTest::readReplicaAddresses ).collect( Collectors.toSet() );