feat: failover read only connections

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

@@ -562,6 +562,22 @@ public boolean isLoginException(final String sqlState) {
     return this.exceptionManager.isLoginException(this.dbDialect, sqlState);
   }
 
+  @Override
+  public boolean isReadOnlyConnectionException(@Nullable String sqlState, @Nullable Integer errorCode) {
+    if (this.exceptionHandler != null) {
+      return this.exceptionHandler.isReadOnlyConnectionException(sqlState, errorCode);
+    }
+    return this.exceptionManager.isReadOnlyConnectionException(this.dbDialect, sqlState, errorCode);
+  }
+
+  @Override
+  public boolean isReadOnlyConnectionException(Throwable throwable, @Nullable TargetDriverDialect targetDriverDialect) {
+    if (this.exceptionHandler != null) {
+      return this.exceptionHandler.isReadOnlyConnectionException(throwable, targetDriverDialect);
+    }
+    return this.exceptionManager.isReadOnlyConnectionException(this.dbDialect, throwable, targetDriverDialect);
+  }
+
   @Override
   public Dialect getDialect() {
     return this.dbDialect;

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

@@ -690,6 +690,22 @@ public boolean isLoginException(final String sqlState) {
     return this.exceptionManager.isLoginException(this.dialect, sqlState);
   }
 
+  @Override
+  public boolean isReadOnlyConnectionException(@Nullable String sqlState, @Nullable Integer errorCode) {
+    if (this.exceptionHandler != null) {
+      return this.exceptionHandler.isReadOnlyConnectionException(sqlState, errorCode);
+    }
+    return this.exceptionManager.isReadOnlyConnectionException(this.dialect, sqlState, errorCode);
+  }
+
+  @Override
+  public boolean isReadOnlyConnectionException(Throwable throwable, @Nullable TargetDriverDialect targetDriverDialect) {
+    if (this.exceptionHandler != null) {
+      return this.exceptionHandler.isReadOnlyConnectionException(throwable, targetDriverDialect);
+    }
+    return this.exceptionManager.isReadOnlyConnectionException(this.dialect, throwable, targetDriverDialect);
+  }
+
   @Override
   public Dialect getDialect() {
     return this.dialect;

wrapper/src/main/java/software/amazon/jdbc/exceptions/AbstractPgExceptionHandler.java

@@ -23,6 +23,9 @@
 import software.amazon.jdbc.util.StringUtils;
 
 public abstract class AbstractPgExceptionHandler implements ExceptionHandler {
+
+  protected static final String READ_ONLY_CONNECTION_SQLSTATE = "25006";
+
   public abstract List<String> getNetworkErrors();
 
   public abstract List<String> getAccessErrors();
@@ -95,4 +98,36 @@ public boolean isLoginException(final String sqlState) {
     }
     return getAccessErrors().contains(sqlState);
   }
+
+  @Override
+  public boolean isReadOnlyConnectionException(
+      final @Nullable String sqlState, final @Nullable Integer errorCode) {
+    return READ_ONLY_CONNECTION_SQLSTATE.equals(sqlState);
+  }
+
+  @Override
+  public boolean isReadOnlyConnectionException(
+      final Throwable throwable, @Nullable TargetDriverDialect targetDriverDialect) {
+
+    Throwable exception = throwable;
+
+    while (exception != null) {
+      String sqlState = null;
+      Integer errorCode = null;
+      if (exception instanceof SQLException) {
+        sqlState = ((SQLException) exception).getSQLState();
+        errorCode = ((SQLException) exception).getErrorCode();
+      } else if (targetDriverDialect != null) {
+        sqlState = targetDriverDialect.getSQLState(exception);
+      }
+
+      if (isReadOnlyConnectionException(sqlState, errorCode)) {
+        return true;
+      }
+
+      exception = exception.getCause();
+    }
+
+    return false;
+  }
 }

wrapper/src/main/java/software/amazon/jdbc/exceptions/ExceptionHandler.java

@@ -28,4 +28,8 @@ public interface ExceptionHandler {
   boolean isLoginException(String sqlState);
 
   boolean isLoginException(Throwable throwable, @Nullable TargetDriverDialect targetDriverDialect);
+
+  boolean isReadOnlyConnectionException(final @Nullable String sqlState, final @Nullable Integer errorCode);
+
+  boolean isReadOnlyConnectionException(Throwable throwable, @Nullable TargetDriverDialect targetDriverDialect);
 }

wrapper/src/main/java/software/amazon/jdbc/exceptions/ExceptionManager.java

@@ -16,6 +16,7 @@
 
 package software.amazon.jdbc.exceptions;
 
+import org.checkerframework.checker.nullness.qual.Nullable;
 import software.amazon.jdbc.Driver;
 import software.amazon.jdbc.dialect.Dialect;
 import software.amazon.jdbc.targetdriverdialect.TargetDriverDialect;
@@ -44,6 +45,18 @@ public boolean isNetworkException(final Dialect dialect, final String sqlState)
     return handler.isNetworkException(sqlState);
   }
 
+  public boolean isReadOnlyConnectionException(
+      final Dialect dialect, final Throwable throwable, final TargetDriverDialect targetDriverDialect) {
+    final ExceptionHandler handler = getHandler(dialect);
+    return handler.isReadOnlyConnectionException(throwable, targetDriverDialect);
+  }
+
+  public boolean isReadOnlyConnectionException(
+      final Dialect dialect, final @Nullable String sqlState, final @Nullable Integer errorCode) {
+    final ExceptionHandler handler = getHandler(dialect);
+    return handler.isReadOnlyConnectionException(sqlState, errorCode);
+  }
+
   private ExceptionHandler getHandler(final Dialect dialect) {
     final ExceptionHandler customHandler = Driver.getCustomExceptionHandler();
     return customHandler != null ? customHandler : dialect.getExceptionHandler();

wrapper/src/main/java/software/amazon/jdbc/exceptions/GenericExceptionHandler.java

@@ -86,7 +86,7 @@ public boolean isLoginException(final Throwable throwable, TargetDriverDialect t
       if (exception instanceof SQLException) {
         sqlState = ((SQLException) exception).getSQLState();
       } else if (targetDriverDialect != null) {
-        sqlState = targetDriverDialect.getSQLState(throwable);
+        sqlState = targetDriverDialect.getSQLState(exception);
       }
 
       if (isLoginException(sqlState)) {
@@ -103,4 +103,15 @@ public boolean isLoginException(final Throwable throwable, TargetDriverDialect t
   public boolean isLoginException(final String sqlState) {
     return ACCESS_ERRORS.contains(sqlState);
   }
+
+  @Override
+  public boolean isReadOnlyConnectionException(@Nullable String sqlState, @Nullable Integer errorCode) {
+    return false;
+  }
+
+  @Override
+  public boolean isReadOnlyConnectionException(
+      Throwable throwable, @Nullable TargetDriverDialect targetDriverDialect) {
+    return false;
+  }
 }

wrapper/src/main/java/software/amazon/jdbc/exceptions/MySQLExceptionHandler.java

@@ -17,6 +17,9 @@
 package software.amazon.jdbc.exceptions;
 
 import java.sql.SQLException;
+import java.util.Arrays;
+import java.util.HashSet;
+import java.util.Set;
 import org.checkerframework.checker.nullness.qual.Nullable;
 import software.amazon.jdbc.targetdriverdialect.TargetDriverDialect;
 import software.amazon.jdbc.util.StringUtils;
@@ -27,6 +30,11 @@ public class MySQLExceptionHandler implements ExceptionHandler {
   public static final String SET_NETWORK_TIMEOUT_ON_CLOSED_CONNECTION =
       "setNetworkTimeout cannot be called on a closed connection";
 
+  private static final Set<Integer> SQLSTATE_READ_ONLY_CONNECTION = new HashSet<>(Arrays.asList(
+      1290, // The MySQL server is running with the --read-only option, so it cannot execute this statement
+      1836 // Running in read-only mode
+  ));
+
   @Override
   public boolean isNetworkException(final Throwable throwable, @Nullable TargetDriverDialect targetDriverDialect) {
     Throwable exception = throwable;
@@ -81,7 +89,7 @@ public boolean isLoginException(final Throwable throwable, @Nullable TargetDrive
       if (exception instanceof SQLException) {
         sqlState = ((SQLException) exception).getSQLState();
       } else if (targetDriverDialect != null) {
-        sqlState = targetDriverDialect.getSQLState(throwable);
+        sqlState = targetDriverDialect.getSQLState(exception);
       }
 
       if (isLoginException(sqlState)) {
@@ -103,6 +111,39 @@ public boolean isLoginException(final String sqlState) {
     return SQLSTATE_ACCESS_ERROR.equals(sqlState);
   }
 
+  @Override
+  public boolean isReadOnlyConnectionException(
+      final @Nullable String sqlState, final @Nullable Integer errorCode) {
+    // HY000 - generic SQL state; use error code for more specific information
+    return "HY000".equals(sqlState) && errorCode != null && (SQLSTATE_READ_ONLY_CONNECTION.contains(errorCode));
+  }
+
+  @Override
+  public boolean isReadOnlyConnectionException(
+      final Throwable throwable, @Nullable TargetDriverDialect targetDriverDialect) {
+
+    Throwable exception = throwable;
+
+    while (exception != null) {
+      String sqlState = null;
+      Integer errorCode = null;
+      if (exception instanceof SQLException) {
+        sqlState = ((SQLException) exception).getSQLState();
+        errorCode = ((SQLException) exception).getErrorCode();
+      } else if (targetDriverDialect != null) {
+        sqlState = targetDriverDialect.getSQLState(exception);
+      }
+
+      if (isReadOnlyConnectionException(sqlState, errorCode)) {
+        return true;
+      }
+
+      exception = exception.getCause();
+    }
+
+    return false;
+  }
+
   private boolean isHikariMariaDbNetworkException(final SQLException sqlException) {
     return sqlException.getSQLState().equals(SQLSTATE_SYNTAX_ERROR_OR_ACCESS_VIOLATION)
         && sqlException.getMessage().contains(SET_NETWORK_TIMEOUT_ON_CLOSED_CONNECTION);

wrapper/src/main/java/software/amazon/jdbc/plugin/failover/FailoverConnectionPlugin.java

@@ -890,7 +890,14 @@ protected boolean shouldExceptionTriggerConnectionSwitch(final Throwable t) {
       return false;
     }
 
-    return this.pluginService.isNetworkException(t, this.pluginService.getTargetDriverDialect());
+    if (this.pluginService.isNetworkException(t, this.pluginService.getTargetDriverDialect())) {
+      return true;
+    }
+
+    // For STRICT_WRITER failover mode when connection exception indicate that the connection's in read-only mode,
+    // initiate a failover by returning true.
+    return this.failoverMode == FailoverMode.STRICT_WRITER
+      && this.pluginService.isReadOnlyConnectionException(t, this.pluginService.getTargetDriverDialect());
   }
 
   /**

wrapper/src/main/java/software/amazon/jdbc/plugin/failover2/FailoverConnectionPlugin.java

@@ -698,7 +698,14 @@ protected boolean shouldExceptionTriggerConnectionSwitch(final Throwable t) {
       return false;
     }
 
-    return this.pluginService.isNetworkException(t, this.pluginService.getTargetDriverDialect());
+    if (this.pluginService.isNetworkException(t, this.pluginService.getTargetDriverDialect())) {
+      return true;
+    }
+
+    // For STRICT_WRITER failover mode when connection exception indicate that the connection's in read-only mode,
+    // initiate a failover by returning true.
+    return this.failoverMode == FailoverMode.STRICT_WRITER
+      && this.pluginService.isReadOnlyConnectionException(t, this.pluginService.getTargetDriverDialect());
   }
 
   /**

wrapper/src/test/java/software/amazon/jdbc/plugin/failover/FailoverConnectionPluginTest.java

@@ -18,12 +18,15 @@
 
 import static org.junit.jupiter.api.Assertions.assertDoesNotThrow;
 import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertFalse;
 import static org.junit.jupiter.api.Assertions.assertThrows;
+import static org.junit.jupiter.api.Assertions.assertTrue;
 import static org.mockito.ArgumentMatchers.any;
 import static org.mockito.ArgumentMatchers.anyString;
 import static org.mockito.ArgumentMatchers.eq;
 import static org.mockito.Mockito.atLeastOnce;
 import static org.mockito.Mockito.doNothing;
+import static org.mockito.Mockito.doReturn;
 import static org.mockito.Mockito.doThrow;
 import static org.mockito.Mockito.never;
 import static org.mockito.Mockito.spy;
@@ -441,4 +444,17 @@ private void initializePlugin() throws SQLException {
     spyPlugin.setReaderFailoverHandler(mockReaderFailoverHandler);
     // doReturn(mockConnectionService).when(spyPlugin).getConnectionService();
   }
+
+  @Test
+  void test_failover_when_read_only_connection() throws SQLException {
+    initializePlugin();
+    spyPlugin.failoverMode = FailoverMode.STRICT_WRITER;
+
+    when(mockPluginService.isReadOnlyConnectionException(any(), any(TargetDriverDialect.class))).thenReturn(true);
+    assertTrue(spyPlugin.shouldExceptionTriggerConnectionSwitch(new SQLException("test", "any")));
+
+    when(mockPluginService.isReadOnlyConnectionException(any(), any(TargetDriverDialect.class))).thenReturn(false);
+    assertFalse(spyPlugin.shouldExceptionTriggerConnectionSwitch(new SQLException("test", "any")));
+  }
+
 }