Refactor: dialects and host list providers to reduce code duplication

benchmarks/src/jmh/java/software/amazon/jdbc/benchmarks/ConnectionPluginManagerBenchmarks.java

@@ -54,7 +54,7 @@
 import software.amazon.jdbc.ConnectionPluginFactory;
 import software.amazon.jdbc.ConnectionPluginManager;
 import software.amazon.jdbc.ConnectionProvider;
-import software.amazon.jdbc.HostListProviderService;
+import software.amazon.jdbc.hostlistprovider.HostListProviderService;
 import software.amazon.jdbc.HostSpec;
 import software.amazon.jdbc.HostSpecBuilder;
 import software.amazon.jdbc.JdbcMethod;

benchmarks/src/jmh/java/software/amazon/jdbc/benchmarks/PluginBenchmarks.java

@@ -54,7 +54,7 @@
 import software.amazon.jdbc.ConnectionProviderManager;
 import software.amazon.jdbc.Driver;
 import software.amazon.jdbc.HikariPooledConnectionProvider;
-import software.amazon.jdbc.HostListProviderService;
+import software.amazon.jdbc.hostlistprovider.HostListProviderService;
 import software.amazon.jdbc.HostSpec;
 import software.amazon.jdbc.HostSpecBuilder;
 import software.amazon.jdbc.JdbcMethod;

benchmarks/src/jmh/java/software/amazon/jdbc/benchmarks/testplugin/BenchmarkPlugin.java

@@ -28,7 +28,7 @@
 import java.util.Set;
 import java.util.logging.Logger;
 import software.amazon.jdbc.ConnectionPlugin;
-import software.amazon.jdbc.HostListProviderService;
+import software.amazon.jdbc.hostlistprovider.HostListProviderService;
 import software.amazon.jdbc.HostRole;
 import software.amazon.jdbc.HostSpec;
 import software.amazon.jdbc.HostSpecBuilder;

benchmarks/src/jmh/java/software/amazon/jdbc/benchmarks/testplugin/TestConnectionWrapper.java

@@ -20,7 +20,7 @@
 import java.util.Properties;
 import org.checkerframework.checker.nullness.qual.NonNull;
 import software.amazon.jdbc.ConnectionPluginManager;
-import software.amazon.jdbc.HostListProviderService;
+import software.amazon.jdbc.hostlistprovider.HostListProviderService;
 import software.amazon.jdbc.PluginManagerService;
 import software.amazon.jdbc.PluginService;
 import software.amazon.jdbc.wrapper.ConnectionWrapper;

wrapper/src/main/java/software/amazon/jdbc/BlockingHostListProvider.java

@@ -19,6 +19,7 @@
 import java.sql.SQLException;
 import java.util.List;
 import java.util.concurrent.TimeoutException;
+import software.amazon.jdbc.hostlistprovider.HostListProvider;
 
 public interface BlockingHostListProvider extends HostListProvider {
 

wrapper/src/main/java/software/amazon/jdbc/ConnectionPlugin.java

@@ -23,6 +23,7 @@
 import java.util.Map;
 import java.util.Properties;
 import java.util.Set;
+import software.amazon.jdbc.hostlistprovider.HostListProviderService;
 
 /**
  * Interface for connection plugins. This class implements ways to execute a JDBC method and to clean up resources used

wrapper/src/main/java/software/amazon/jdbc/ConnectionPluginManager.java

@@ -30,6 +30,7 @@
 import org.checkerframework.checker.nullness.qual.NonNull;
 import org.checkerframework.checker.nullness.qual.Nullable;
 import software.amazon.jdbc.cleanup.CanReleaseResources;
+import software.amazon.jdbc.hostlistprovider.HostListProviderService;
 import software.amazon.jdbc.plugin.AuroraConnectionTrackerPlugin;
 import software.amazon.jdbc.plugin.AuroraInitialConnectionStrategyPlugin;
 import software.amazon.jdbc.plugin.AwsSecretsManagerConnectionPlugin;

wrapper/src/main/java/software/amazon/jdbc/PartialPluginService.java

@@ -41,11 +41,14 @@
 import software.amazon.jdbc.exceptions.ExceptionManager;
 import software.amazon.jdbc.hostavailability.HostAvailability;
 import software.amazon.jdbc.hostavailability.HostAvailabilityStrategyFactory;
+import software.amazon.jdbc.hostlistprovider.HostListProvider;
+import software.amazon.jdbc.hostlistprovider.HostListProviderService;
 import software.amazon.jdbc.hostlistprovider.StaticHostListProvider;
 import software.amazon.jdbc.profile.ConfigurationProfile;
 import software.amazon.jdbc.states.SessionStateService;
 import software.amazon.jdbc.targetdriverdialect.TargetDriverDialect;
 import software.amazon.jdbc.util.FullServicesContainer;
+import software.amazon.jdbc.util.LogUtils;
 import software.amazon.jdbc.util.Messages;
 import software.amazon.jdbc.util.Utils;
 import software.amazon.jdbc.util.storage.CacheMap;
@@ -130,7 +133,7 @@ public PartialPluginService(
         ? this.configurationProfile.getExceptionHandler()
         : null;
 
-    HostListProviderSupplier supplier = this.dbDialect.getHostListProvider();
+    HostListProviderSupplier supplier = this.dbDialect.getHostListProviderSupplier();
     this.hostListProvider = supplier.getProvider(this.props, this.originalUrl, this.servicesContainer);
   }
 
@@ -157,7 +160,7 @@ public HostSpec getCurrentHostSpec() {
               Messages.get("PluginServiceImpl.currentHostNotAllowed",
                   new Object[] {
                       currentHostSpec == null ? "<null>" : currentHostSpec.getHostAndPort(),
-                      Utils.logTopology(allowedHosts, "")})
+                      LogUtils.logTopology(allowedHosts, "")})
           );
         }
 

wrapper/src/main/java/software/amazon/jdbc/PluginService.java

@@ -28,6 +28,7 @@
 import software.amazon.jdbc.dialect.Dialect;
 import software.amazon.jdbc.exceptions.ExceptionHandler;
 import software.amazon.jdbc.hostavailability.HostAvailability;
+import software.amazon.jdbc.hostlistprovider.HostListProvider;
 import software.amazon.jdbc.states.SessionStateService;
 import software.amazon.jdbc.targetdriverdialect.TargetDriverDialect;
 import software.amazon.jdbc.util.telemetry.TelemetryFactory;

wrapper/src/main/java/software/amazon/jdbc/PluginServiceImpl.java

@@ -46,12 +46,15 @@
 import software.amazon.jdbc.exceptions.ExceptionManager;
 import software.amazon.jdbc.hostavailability.HostAvailability;
 import software.amazon.jdbc.hostavailability.HostAvailabilityStrategyFactory;
+import software.amazon.jdbc.hostlistprovider.HostListProvider;
+import software.amazon.jdbc.hostlistprovider.HostListProviderService;
 import software.amazon.jdbc.hostlistprovider.StaticHostListProvider;
 import software.amazon.jdbc.profile.ConfigurationProfile;
 import software.amazon.jdbc.states.SessionStateService;
 import software.amazon.jdbc.states.SessionStateServiceImpl;
 import software.amazon.jdbc.targetdriverdialect.TargetDriverDialect;
 import software.amazon.jdbc.util.FullServicesContainer;
+import software.amazon.jdbc.util.LogUtils;
 import software.amazon.jdbc.util.Messages;
 import software.amazon.jdbc.util.Utils;
 import software.amazon.jdbc.util.storage.CacheMap;
@@ -191,7 +194,7 @@ public HostSpec getCurrentHostSpec() {
               Messages.get("PluginServiceImpl.currentHostNotAllowed",
                   new Object[] {
                       currentHostSpec == null ? "<null>" : currentHostSpec.getHostAndPort(),
-                      Utils.logTopology(allowedHosts, "")})
+                      LogUtils.logTopology(allowedHosts, "")})
           );
         }
 
@@ -707,7 +710,7 @@ public void updateDialect(final @NonNull Connection connection) throws SQLExcept
       return;
     }
 
-    final HostListProviderSupplier supplier = this.dialect.getHostListProvider();
+    final HostListProviderSupplier supplier = this.dialect.getHostListProviderSupplier();
     this.setHostListProvider(supplier.getProvider(this.props, this.originalUrl, this.servicesContainer));
     this.refreshHostList(connection);
   }

wrapper/src/main/java/software/amazon/jdbc/dialect/AuroraMysqlDialect.java

@@ -17,119 +17,85 @@
 package software.amazon.jdbc.dialect;
 
 import java.sql.Connection;
-import java.sql.ResultSet;
-import java.sql.SQLException;
-import java.sql.Statement;
-import java.util.Arrays;
 import java.util.Collections;
 import java.util.List;
 import software.amazon.jdbc.PluginService;
-import software.amazon.jdbc.hostlistprovider.AuroraHostListProvider;
+import software.amazon.jdbc.hostlistprovider.AuroraTopologyUtils;
+import software.amazon.jdbc.hostlistprovider.RdsHostListProvider;
+import software.amazon.jdbc.hostlistprovider.TopologyUtils;
 import software.amazon.jdbc.hostlistprovider.monitoring.MonitoringRdsHostListProvider;
 import software.amazon.jdbc.plugin.failover2.FailoverConnectionPlugin;
 
-public class AuroraMysqlDialect extends MysqlDialect implements BlueGreenDialect {
+public class AuroraMysqlDialect extends MysqlDialect implements TopologyDialect, BlueGreenDialect {
 
-  protected final String topologyQuery =
+  protected static final String AURORA_VERSION_EXISTS_QUERY = "SHOW VARIABLES LIKE 'aurora_version'";
+  protected static final String TOPOLOGY_QUERY =
       "SELECT SERVER_ID, CASE WHEN SESSION_ID = 'MASTER_SESSION_ID' THEN TRUE ELSE FALSE END, "
           + "CPU, REPLICA_LAG_IN_MILLISECONDS, LAST_UPDATE_TIMESTAMP "
           + "FROM information_schema.replica_host_status "
-          // filter out nodes that haven't been updated in the last 5 minutes
+          // filter out instances that have not been updated in the last 5 minutes
           + "WHERE time_to_sec(timediff(now(), LAST_UPDATE_TIMESTAMP)) <= 300 OR SESSION_ID = 'MASTER_SESSION_ID' ";
 
-  protected final String isWriterQuery =
+  protected static final String INSTANCE_ID_QUERY = "SELECT @@aurora_server_id, @@aurora_server_id";
+  protected static final String WRITER_ID_QUERY =
       "SELECT SERVER_ID FROM information_schema.replica_host_status "
-      + "WHERE SESSION_ID = 'MASTER_SESSION_ID' AND SERVER_ID = @@aurora_server_id";
+          + "WHERE SESSION_ID = 'MASTER_SESSION_ID' AND SERVER_ID = @@aurora_server_id";
+  protected static final String IS_READER_QUERY = "SELECT @@innodb_read_only";
 
-  protected final String nodeIdQuery = "SELECT @@aurora_server_id, @@aurora_server_id";
-  protected final String isReaderQuery = "SELECT @@innodb_read_only";
-
-  private static final String BG_STATUS_QUERY =
-      "SELECT * FROM mysql.rds_topology";
-
-  private static final String TOPOLOGY_TABLE_EXIST_QUERY =
+  protected static final String BG_TOPOLOGY_EXISTS_QUERY =
       "SELECT 1 AS tmp FROM information_schema.tables WHERE"
           + " table_schema = 'mysql' AND table_name = 'rds_topology'";
+  protected static final String BG_STATUS_QUERY = "SELECT * FROM mysql.rds_topology";
 
   @Override
   public boolean isDialect(final Connection connection) {
-    Statement stmt = null;
-    ResultSet rs = null;
-    try {
-      stmt = connection.createStatement();
-      rs = stmt.executeQuery("SHOW VARIABLES LIKE 'aurora_version'");
-      if (rs.next()) {
-        // If variable with such name is presented then it means it's an Aurora cluster
-        return true;
-      }
-    } catch (final SQLException ex) {
-      // ignore
-    } finally {
-      if (stmt != null) {
-        try {
-          stmt.close();
-        } catch (SQLException ex) {
-          // ignore
-        }
-      }
-      if (rs != null) {
-        try {
-          rs.close();
-        } catch (SQLException ex) {
-          // ignore
-        }
-      }
-    }
-    return false;
+    return dialectUtils.checkExistenceQueries(connection, AURORA_VERSION_EXISTS_QUERY);
   }
 
   @Override
   public List</* dialect code */ String> getDialectUpdateCandidates() {
-    return Arrays.asList(
-        DialectCodes.GLOBAL_AURORA_MYSQL,
-        DialectCodes.RDS_MULTI_AZ_MYSQL_CLUSTER);
+    return Collections.singletonList(DialectCodes.RDS_MULTI_AZ_MYSQL_CLUSTER);
   }
 
   @Override
-  public HostListProviderSupplier getHostListProvider() {
+  public HostListProviderSupplier getHostListProviderSupplier() {
     return (properties, initialUrl, servicesContainer) -> {
       final PluginService pluginService = servicesContainer.getPluginService();
+      final TopologyUtils topologyUtils = new AuroraTopologyUtils(this, pluginService.getHostSpecBuilder());
       if (pluginService.isPluginInUse(FailoverConnectionPlugin.class)) {
-        return new MonitoringRdsHostListProvider(
-            properties,
-            initialUrl,
-            servicesContainer,
-            this.topologyQuery,
-            this.nodeIdQuery,
-            this.isReaderQuery,
-            this.isWriterQuery);
+        return new MonitoringRdsHostListProvider(topologyUtils, properties, initialUrl, servicesContainer);
       }
-      return new AuroraHostListProvider(
-          properties,
-          initialUrl,
-          servicesContainer,
-          this.topologyQuery,
-          this.nodeIdQuery,
-          this.isReaderQuery);
+      return new RdsHostListProvider(topologyUtils, properties, initialUrl, servicesContainer);
     };
   }
 
   @Override
-  public String getBlueGreenStatusQuery() {
-    return BG_STATUS_QUERY;
+  public String getTopologyQuery() {
+    return TOPOLOGY_QUERY;
+  }
+
+  @Override
+  public String getInstanceIdQuery() {
+    return INSTANCE_ID_QUERY;
+  }
+
+  @Override
+  public String getWriterIdQuery() {
+    return WRITER_ID_QUERY;
+  }
+
+  @Override
+  public String getIsReaderQuery() {
+    return IS_READER_QUERY;
   }
 
   @Override
   public boolean isBlueGreenStatusAvailable(final Connection connection) {
-    try {
-      try (Statement statement = connection.createStatement();
-          ResultSet rs = statement.executeQuery(TOPOLOGY_TABLE_EXIST_QUERY)) {
-        return rs.next();
-      }
-    } catch (SQLException ex) {
-      return false;
-    }
+    return dialectUtils.checkExistenceQueries(connection, BG_TOPOLOGY_EXISTS_QUERY);
   }
 
+  @Override
+  public String getBlueGreenStatusQuery() {
+    return BG_STATUS_QUERY;
+  }
 }
-