test: re-enable tests

wrapper/src/main/java/com/amazon/awslabs/jdbc/hostlistprovider/AuroraHostListProvider.java

@@ -35,12 +35,13 @@
 import java.time.Duration;
 import java.time.Instant;
 import java.util.ArrayList;
+import java.util.Arrays;
 import java.util.Collections;
-import java.util.HashSet;
 import java.util.List;
 import java.util.Properties;
 import java.util.Set;
 import java.util.UUID;
+import java.util.concurrent.ConcurrentHashMap;
 import java.util.logging.Level;
 import java.util.logging.Logger;
 import org.checkerframework.checker.nullness.qual.Nullable;
@@ -98,7 +99,7 @@ public class AuroraHostListProvider implements HostListProvider, DynamicHostList
   private final int refreshRateInMilliseconds;
   private List<HostSpec> hostList = new ArrayList<>();
 
-  static final ExpiringCache<String, ClusterTopologyInfo> topologyCache =
+  protected static final ExpiringCache<String, ClusterTopologyInfo> topologyCache =
       new ExpiringCache<>(DEFAULT_CACHE_EXPIRE_MS);
   private static final Object cacheLock = new Object();
 
@@ -224,7 +225,7 @@ protected ClusterTopologyInfo queryForTopology(final Connection conn) throws SQL
       // ignore
     }
 
-    return new ClusterTopologyInfo(hosts, new HashSet<>(), Instant.now(), false);
+    return new ClusterTopologyInfo(hosts, ConcurrentHashMap.newKeySet(), Instant.now(), false);
   }
 
   /**
@@ -362,7 +363,7 @@ public Set<String> getDownHosts() {
       ClusterTopologyInfo clusterTopologyInfo = topologyCache.get(this.clusterId);
       return clusterTopologyInfo != null && clusterTopologyInfo.downHosts != null
           ? clusterTopologyInfo.downHosts
-          : new HashSet<>();
+          : ConcurrentHashMap.newKeySet();
     }
   }
 
@@ -379,10 +380,10 @@ public void addToDownHostList(HostSpec downHost) {
       ClusterTopologyInfo clusterTopologyInfo = topologyCache.get(this.clusterId);
       if (clusterTopologyInfo == null) {
         clusterTopologyInfo =
-            new ClusterTopologyInfo(new ArrayList<>(), new HashSet<>(), Instant.now(), false);
+            new ClusterTopologyInfo(new ArrayList<>(), ConcurrentHashMap.newKeySet(), Instant.now(), false);
         topologyCache.put(this.clusterId, clusterTopologyInfo);
       } else if (clusterTopologyInfo.downHosts == null) {
-        clusterTopologyInfo.downHosts = new HashSet<>();
+        clusterTopologyInfo.downHosts = ConcurrentHashMap.newKeySet();
       }
       clusterTopologyInfo.downHosts.add(downHost.getUrl());
       this.pluginService.setAvailability(downHost.getAliases(), HostAvailability.NOT_AVAILABLE);

wrapper/src/main/java/com/amazon/awslabs/jdbc/plugin/failover/ClusterAwareReaderFailoverHandler.java

@@ -26,6 +26,7 @@
 import java.sql.Connection;
 import java.sql.SQLException;
 import java.util.ArrayList;
+import java.util.Arrays;
 import java.util.Collections;
 import java.util.List;
 import java.util.Properties;
@@ -430,5 +431,10 @@ public HostSpec getHost() {
     public int getIndex() {
       return index;
     }
+
+    @Override
+    public String toString() {
+      return String.format("host: %s, index: %d", host, index);
+    }
   }
 }

wrapper/src/main/java/com/amazon/awslabs/jdbc/plugin/failover/ClusterAwareWriterFailoverHandler.java

@@ -372,10 +372,10 @@ private boolean refreshTopologyAndConnectToNewWriter() throws InterruptedExcepti
           if (!topology.isEmpty()) {
             this.currentTopology = topology;
             HostSpec writerCandidate = this.currentTopology.get(WRITER_CONNECTION_INDEX);
-            logTopology();
 
             if (!isSame(writerCandidate, this.originalWriterHost)) {
               // new writer is available and it's different from the previous writer
+              logTopology();
               if (connectToWriter(writerCandidate)) {
                 return true;
               }

wrapper/src/main/resources/messages.properties

@@ -21,8 +21,8 @@ Failover.parameterValue={0}={1}
 Failover.unableToConnectToWriter=Unable to establish SQL connection to the writer instance
 Failover.unableToConnectToReader=Unable to establish SQL connection to the reader instance.
 Failover.detectedException=Detected an exception while executing a command: {0}.
-Failover.failoverDisabled=Cluster-aware failover is disabled.
-Failover.failoverEnabled=Cluster-aware failover is enabled.
+Failover.failoverDisabled=Cluster-aware failover is disabled
+Failover.failoverEnabled=Cluster-aware failover is enabled
 Failover.establishedConnection=Connected to: {0}
 Failover.startWriterFailover=Starting writer failover procedure.
 Failover.startReaderFailover=Starting reader failover procedure.

wrapper/src/test/java/integration/container/aurora/postgres/AuroraPostgresBaseTest.java

@@ -214,6 +214,7 @@ public void setUpEach() throws InterruptedException, SQLException {
         clusterSize >= 2); // many tests assume that cluster contains at least a writer and a reader
     assertTrue(isDBInstanceWriter(instanceIDs[0]));
     makeSureInstancesUp(instanceIDs);
+    TestAuroraHostListProvider.clearCache();
   }
 
   protected Properties initDefaultPropsNoTimeouts() {

wrapper/src/test/java/integration/container/aurora/postgres/AuroraPostgresIntegrationTest.java

@@ -408,7 +408,6 @@ public void test_failFromReaderToReaderWithSomeReadersAreDown()
    * revive previously down reader instance.
    */
   @Test
-  @Disabled
   public void test_failoverBackToThePreviouslyDownReader() throws Exception {
 
     assertTrue(clusterSize >= 5, "Minimal cluster configuration: 1 writer + 4 readers");

wrapper/src/test/java/integration/container/aurora/postgres/TestAuroraHostListProvider.java

@@ -0,0 +1,33 @@
+/*
+ * Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+ *
+ * Licensed 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 integration.container.aurora.postgres;
+
+import com.amazon.awslabs.jdbc.PluginService;
+import com.amazon.awslabs.jdbc.hostlistprovider.AuroraHostListProvider;
+import java.util.Properties;
+
+public class TestAuroraHostListProvider extends AuroraHostListProvider {
+
+  public TestAuroraHostListProvider(String driverProtocol, PluginService pluginService,
+      Properties properties, String originalUrl) {
+    super(driverProtocol, pluginService, properties, originalUrl);
+  }
+
+  public static void clearCache() {
+    AuroraHostListProvider.topologyCache.clear();
+  }
+}

wrapper/src/test/java/integration/container/standard/postgres/StandardPostgresDataSourceTest.java

@@ -24,6 +24,7 @@
 import java.sql.Connection;
 import java.sql.SQLException;
 import java.util.Properties;
+import org.junit.jupiter.api.Disabled;
 import org.junit.jupiter.api.Test;
 import org.postgresql.util.PSQLException;