Examples with LeaderChangedException herddb.client.impl.LeaderChangedException used on opensource projects

Example 1 with LeaderChangedException

use of herddb.client.impl.LeaderChangedException in project herddb by diennea.

the class EmbeddedBookieTest method testBootWithBookie.

private void testBootWithBookie(boolean useBookiedId, boolean automaticNodeId) throws Exception {
    ServerConfiguration serverconfig_1 = newServerConfigurationWithAutoPort(folder.newFolder("server1").toPath());
    if (!automaticNodeId) {
        serverconfig_1.set(ServerConfiguration.PROPERTY_NODEID, "server1");
    }
    serverconfig_1.set(ServerConfiguration.PROPERTY_MODE, ServerConfiguration.PROPERTY_MODE_CLUSTER);
    serverconfig_1.set(ServerConfiguration.PROPERTY_ZOOKEEPER_ADDRESS, testEnv.getAddress());
    serverconfig_1.set(ServerConfiguration.PROPERTY_ZOOKEEPER_PATH, testEnv.getPath());
    serverconfig_1.set(ServerConfiguration.PROPERTY_ZOOKEEPER_SESSIONTIMEOUT, testEnv.getTimeout());
    serverconfig_1.set(ServerConfiguration.PROPERTY_BOOKKEEPER_START, true);
    serverconfig_1.set(ServerConfiguration.PROPERTY_BOOKKEEPER_BOOKIE_PORT, 0);
    serverconfig_1.set(ServerConfiguration.PROPERTY_BOOKKEEPER_BOOKIE_BOOKIEID_ENABLED, useBookiedId);
    serverconfig_1.set("bookie.allowLoopback", true);
    ServerConfiguration serverconfig_2 = serverconfig_1.copy().set(ServerConfiguration.PROPERTY_NODEID, "server2").set(ServerConfiguration.PROPERTY_BASEDIR, folder.newFolder("server2").toPath().toAbsolutePath());
    try (Server server_1 = new Server(serverconfig_1)) {
        server_1.start();
        if (automaticNodeId) {
            assertNotEquals("server1", server_1.getNodeId());
        } else {
            assertEquals("server1", server_1.getNodeId());
        }
        server_1.waitForStandaloneBoot();
        if (useBookiedId) {
            assertEquals(server_1.getEmbeddedBookie().getBookieId(), server_1.getNodeId());
        }
        Table table = Table.builder().name("t1").column("c", ColumnTypes.INTEGER).primaryKey("c").build();
        server_1.getManager().executeStatement(new CreateTableStatement(table), StatementEvaluationContext.DEFAULT_EVALUATION_CONTEXT(), TransactionContext.NO_TRANSACTION);
        server_1.getManager().executeUpdate(new InsertStatement(TableSpace.DEFAULT, "t1", RecordSerializer.makeRecord(table, "c", 1)), StatementEvaluationContext.DEFAULT_EVALUATION_CONTEXT(), TransactionContext.NO_TRANSACTION);
        server_1.getManager().executeUpdate(new InsertStatement(TableSpace.DEFAULT, "t1", RecordSerializer.makeRecord(table, "c", 2)), StatementEvaluationContext.DEFAULT_EVALUATION_CONTEXT(), TransactionContext.NO_TRANSACTION);
        try (Server server_2 = new Server(serverconfig_2)) {
            server_2.start();
            server_1.getManager().executeStatement(new AlterTableSpaceStatement(TableSpace.DEFAULT, new HashSet<>(Arrays.asList(server_1.getNodeId(), server_2.getNodeId())), server_1.getNodeId(), 1, 0), StatementEvaluationContext.DEFAULT_EVALUATION_CONTEXT(), TransactionContext.NO_TRANSACTION);
            assertTrue(server_2.getManager().waitForTablespace(TableSpace.DEFAULT, 60000, false));
            server_2.getManager().setErrorIfNotLeader(false);
            // wait for data to arrive on server_2
            for (int i = 0; i < 100; i++) {
                GetResult found = server_2.getManager().get(new GetStatement(TableSpace.DEFAULT, "t1", Bytes.from_int(1), null, false), StatementEvaluationContext.DEFAULT_EVALUATION_CONTEXT(), TransactionContext.NO_TRANSACTION);
                if (found.found()) {
                    break;
                }
                Thread.sleep(100);
            }
            assertTrue(server_2.getManager().get(new GetStatement(TableSpace.DEFAULT, "t1", Bytes.from_int(1), null, false), StatementEvaluationContext.DEFAULT_EVALUATION_CONTEXT(), TransactionContext.NO_TRANSACTION).found());
            server_2.getManager().setErrorIfNotLeader(true);
            ClientConfiguration client_configuration = new ClientConfiguration(folder.newFolder().toPath());
            client_configuration.set(ClientConfiguration.PROPERTY_MODE, ServerConfiguration.PROPERTY_MODE_CLUSTER);
            client_configuration.set(ClientConfiguration.PROPERTY_ZOOKEEPER_ADDRESS, testEnv.getAddress());
            client_configuration.set(ClientConfiguration.PROPERTY_ZOOKEEPER_PATH, testEnv.getPath());
            client_configuration.set(ClientConfiguration.PROPERTY_ZOOKEEPER_SESSIONTIMEOUT, testEnv.getTimeout());
            try (HDBClient client = new HDBClient(client_configuration);
                HDBConnection connection = client.openConnection()) {
                try (ScanResultSet scan = connection.executeScan(TableSpace.DEFAULT, "SELECT * FROM t1 WHERE c=1", true, Collections.emptyList(), 0, 0, 10, true)) {
                    assertEquals(1, scan.consume().size());
                }
                // switch leader to server2
                server_2.getManager().executeStatement(new AlterTableSpaceStatement(TableSpace.DEFAULT, new HashSet<>(Arrays.asList(server_1.getNodeId(), server_2.getNodeId())), server_2.getNodeId(), 1, 0), StatementEvaluationContext.DEFAULT_EVALUATION_CONTEXT(), TransactionContext.NO_TRANSACTION);
                // wait that server_1 leaves leadership
                for (int i = 0; i < 100; i++) {
                    TableSpaceManager tManager = server_1.getManager().getTableSpaceManager(TableSpace.DEFAULT);
                    if (tManager != null && !tManager.isLeader()) {
                        break;
                    }
                    Thread.sleep(100);
                }
                TableSpaceManager tManager = server_1.getManager().getTableSpaceManager(TableSpace.DEFAULT);
                assertTrue(tManager != null && !tManager.isLeader());
                // the client MUST automatically look for the new leader
                try (ScanResultSet scan = connection.executeScan(TableSpace.DEFAULT, "SELECT * FROM t1 WHERE c=1", true, Collections.emptyList(), 0, 0, 10, true)) {
                    assertEquals(1, scan.consume().size());
                }
            }
            // assert  that server_1 is not accepting request any more
            try (HDBClient client_to_1 = new HDBClient(new ClientConfiguration(folder.newFolder().toPath()));
                HDBConnection connection = client_to_1.openConnection()) {
                client_to_1.setClientSideMetadataProvider(new StaticClientSideMetadataProvider(server_1) {

                    @Override
                    public void requestMetadataRefresh(Exception error) throws ClientSideMetadataProviderException {
                        assertTrue(error instanceof LeaderChangedException);
                        throw new ClientSideMetadataProviderException(error);
                    }
                });
                try (ScanResultSet scan = connection.executeScan(TableSpace.DEFAULT, "SELECT * FROM t1 WHERE c=1", true, Collections.emptyList(), 0, 0, 10, true)) {
                    fail("server_1 MUST not accept queries");
                } catch (ClientSideMetadataProviderException ok) {
                    assertTrue(ok.getCause() instanceof LeaderChangedException);
                }
            }
            // assert that server_2 is accepting requests
            try (HDBClient client_to_2 = new HDBClient(new ClientConfiguration(folder.newFolder().toPath()));
                HDBConnection connection = client_to_2.openConnection()) {
                client_to_2.setClientSideMetadataProvider(new StaticClientSideMetadataProvider(server_2));
                try (ScanResultSet scan = connection.executeScan(TableSpace.DEFAULT, "SELECT * FROM t1 WHERE c=1", true, Collections.emptyList(), 0, 0, 10, true)) {
                    assertEquals(1, scan.consume().size());
                }
            }
        }
    }
}

Example 2 with LeaderChangedException

use of herddb.client.impl.LeaderChangedException in project herddb by diennea.

the class ClientMultiServerTest method testLeaderChanged.

private void testLeaderChanged(boolean becomesFollower) throws Exception {
    ServerConfiguration serverconfig_1 = newServerConfigurationWithAutoPort(folder.newFolder("server1").toPath());
    serverconfig_1.set(ServerConfiguration.PROPERTY_NODEID, "server1");
    serverconfig_1.set(ServerConfiguration.PROPERTY_MODE, ServerConfiguration.PROPERTY_MODE_CLUSTER);
    serverconfig_1.set(ServerConfiguration.PROPERTY_ZOOKEEPER_ADDRESS, testEnv.getAddress());
    serverconfig_1.set(ServerConfiguration.PROPERTY_ZOOKEEPER_PATH, testEnv.getPath());
    serverconfig_1.set(ServerConfiguration.PROPERTY_ZOOKEEPER_SESSIONTIMEOUT, testEnv.getTimeout());
    serverconfig_1.set(ServerConfiguration.PROPERTY_PLANNER_WAITFORTABLESPACE_TIMEOUT, 1000);
    ServerConfiguration serverconfig_2 = serverconfig_1.copy().set(ServerConfiguration.PROPERTY_NODEID, "server2").set(ServerConfiguration.PROPERTY_BASEDIR, folder.newFolder("server2").toPath().toAbsolutePath());
    try (Server server_1 = new Server(serverconfig_1)) {
        server_1.start();
        server_1.waitForStandaloneBoot();
        Table table = Table.builder().name("t1").column("c", ColumnTypes.INTEGER).column("d", ColumnTypes.INTEGER).primaryKey("c").build();
        server_1.getManager().executeStatement(new CreateTableStatement(table), StatementEvaluationContext.DEFAULT_EVALUATION_CONTEXT(), TransactionContext.NO_TRANSACTION);
        server_1.getManager().executeUpdate(new InsertStatement(TableSpace.DEFAULT, "t1", RecordSerializer.makeRecord(table, "c", 1)), StatementEvaluationContext.DEFAULT_EVALUATION_CONTEXT(), TransactionContext.NO_TRANSACTION);
        server_1.getManager().executeUpdate(new InsertStatement(TableSpace.DEFAULT, "t1", RecordSerializer.makeRecord(table, "c", 2)), StatementEvaluationContext.DEFAULT_EVALUATION_CONTEXT(), TransactionContext.NO_TRANSACTION);
        try (Server server_2 = new Server(serverconfig_2)) {
            server_2.start();
            server_1.getManager().executeStatement(new AlterTableSpaceStatement(TableSpace.DEFAULT, new HashSet<>(Arrays.asList("server1", "server2")), "server1", 1, 0), StatementEvaluationContext.DEFAULT_EVALUATION_CONTEXT(), TransactionContext.NO_TRANSACTION);
            assertTrue(server_2.getManager().waitForTablespace(TableSpace.DEFAULT, 60000, false));
            server_2.getManager().setErrorIfNotLeader(false);
            // wait for data to arrive on server_2
            for (int i = 0; i < 100; i++) {
                GetResult found = server_2.getManager().get(new GetStatement(TableSpace.DEFAULT, "t1", Bytes.from_int(1), null, false), StatementEvaluationContext.DEFAULT_EVALUATION_CONTEXT(), TransactionContext.NO_TRANSACTION);
                if (found.found()) {
                    break;
                }
                Thread.sleep(100);
            }
            assertTrue(server_2.getManager().get(new GetStatement(TableSpace.DEFAULT, "t1", Bytes.from_int(1), null, false), StatementEvaluationContext.DEFAULT_EVALUATION_CONTEXT(), TransactionContext.NO_TRANSACTION).found());
            server_2.getManager().setErrorIfNotLeader(true);
            ClientConfiguration client_configuration = new ClientConfiguration(folder.newFolder().toPath());
            client_configuration.set(ClientConfiguration.PROPERTY_MODE, ServerConfiguration.PROPERTY_MODE_CLUSTER);
            client_configuration.set(ClientConfiguration.PROPERTY_ZOOKEEPER_ADDRESS, testEnv.getAddress());
            client_configuration.set(ClientConfiguration.PROPERTY_ZOOKEEPER_PATH, testEnv.getPath());
            client_configuration.set(ClientConfiguration.PROPERTY_ZOOKEEPER_SESSIONTIMEOUT, testEnv.getTimeout());
            try (HDBClient client = new HDBClient(client_configuration);
                HDBConnection connection = client.openConnection()) {
                try (ScanResultSet scan = connection.executeScan(TableSpace.DEFAULT, "SELECT * FROM t1 WHERE c=1", true, Collections.emptyList(), 0, 0, 10, true)) {
                    assertEquals(1, scan.consume().size());
                }
                Set<String> newReplicaList;
                if (becomesFollower) {
                    newReplicaList = new HashSet<>(Arrays.asList("server1", "server2"));
                } else {
                    newReplicaList = new HashSet<>(Arrays.asList("server2"));
                }
                // switch leader to server2
                server_2.getManager().executeStatement(new AlterTableSpaceStatement(TableSpace.DEFAULT, newReplicaList, "server2", 1, 0), StatementEvaluationContext.DEFAULT_EVALUATION_CONTEXT(), TransactionContext.NO_TRANSACTION);
                // wait that server_1 leaves leadership
                for (int i = 0; i < 100; i++) {
                    TableSpaceManager tManager = server_1.getManager().getTableSpaceManager(TableSpace.DEFAULT);
                    if (becomesFollower) {
                        // wait for server1 to become follower
                        if (tManager != null && !tManager.isLeader() && !tManager.isFailed()) {
                            break;
                        }
                    } else {
                        // wait for server1 to become shutdown and lose the tablespace
                        if (tManager == null) {
                            break;
                        }
                    }
                    Thread.sleep(100);
                }
                if (becomesFollower) {
                    TableSpaceManager tManager = server_1.getManager().getTableSpaceManager(TableSpace.DEFAULT);
                    assertTrue(tManager != null && !tManager.isLeader());
                } else {
                    TableSpaceManager tManager = server_1.getManager().getTableSpaceManager(TableSpace.DEFAULT);
                    assertNull(tManager);
                }
                // the client MUST automatically look for the new leader
                try (ScanResultSet scan = connection.executeScan(TableSpace.DEFAULT, "SELECT * FROM t1 WHERE c=1", true, Collections.emptyList(), 0, 0, 10, true)) {
                    assertEquals(1, scan.consume().size());
                }
            }
            // assert  that server_1 is not accepting request any more
            try (HDBClient client_to_1 = new HDBClient(new ClientConfiguration(folder.newFolder().toPath()));
                HDBConnection connection = client_to_1.openConnection()) {
                client_to_1.setClientSideMetadataProvider(new StaticClientSideMetadataProvider(server_1) {

                    @Override
                    public void requestMetadataRefresh(Exception error) throws ClientSideMetadataProviderException {
                        assertTrue(error instanceof LeaderChangedException);
                        throw new ClientSideMetadataProviderException(error);
                    }
                });
                // with prepare statement
                try (ScanResultSet scan = connection.executeScan(TableSpace.DEFAULT, "SELECT * FROM t1 WHERE c=1", true, Collections.emptyList(), 0, 0, 10, true)) {
                    fail("server_1 MUST not accept queries");
                } catch (ClientSideMetadataProviderException ok) {
                    assertTrue(ok.getCause() instanceof LeaderChangedException);
                }
                // without prepare statement
                try (ScanResultSet scan = connection.executeScan(TableSpace.DEFAULT, "SELECT * FROM t1 WHERE c=1", false, Collections.emptyList(), 0, 0, 10, true)) {
                    fail("server_1 MUST not accept queries");
                } catch (ClientSideMetadataProviderException ok) {
                    assertTrue(ok.getCause() instanceof LeaderChangedException);
                }
                // with prepare statement
                try {
                    connection.executeUpdate(TableSpace.DEFAULT, "UPDATE t1 set d=2 WHERE c=1", 0, false, true, Collections.emptyList());
                    fail("server_1 MUST not accept queries");
                } catch (ClientSideMetadataProviderException ok) {
                    assertTrue(ok.getCause() instanceof LeaderChangedException);
                }
                // ensure that we don't use internal plans cache
                server_1.getManager().getPlanner().clearCache();
                server_2.getManager().getPlanner().clearCache();
                // without prepare statement
                try {
                    connection.executeUpdate(TableSpace.DEFAULT, "UPDATE t1 set d=2 WHERE c=1", 0, false, false, Collections.emptyList());
                    fail("server_1 MUST not accept queries");
                } catch (ClientSideMetadataProviderException ok) {
                    assertTrue(ok.getCause() instanceof LeaderChangedException);
                }
            }
            // assert that server_2 is accepting requests
            try (HDBClient client_to_2 = new HDBClient(new ClientConfiguration(folder.newFolder().toPath()));
                HDBConnection connection = client_to_2.openConnection()) {
                client_to_2.setClientSideMetadataProvider(new StaticClientSideMetadataProvider(server_2));
                try (ScanResultSet scan = connection.executeScan(TableSpace.DEFAULT, "SELECT * FROM t1 WHERE c=1", true, Collections.emptyList(), 0, 0, 10, true)) {
                    assertEquals(1, scan.consume().size());
                }
            }
        }
    }
}

Example 3 with LeaderChangedException

use of herddb.client.impl.LeaderChangedException in project herddb by diennea.

the class HDBConnection method handleRetryError.

private void handleRetryError(Throwable retry, int trialCount) throws HDBException, ClientSideMetadataProviderException {
    // no stracktrace
    LOGGER.log(Level.INFO, "retry #{0}:" + retry, trialCount);
    int sleepTimeout = client.getOperationRetryDelay();
    int maxTrials = client.getMaxOperationRetryCount();
    if (retry instanceof RetryRequestException) {
        RetryRequestException retryError = (RetryRequestException) retry;
        // Use implicit error max trials if override configuration
        int errorMaxTrials = retryError.getMaxRetry();
        if (errorMaxTrials != RetryRequestException.MAX_RETRY_NO_OVERRIDE) {
            maxTrials = errorMaxTrials;
        }
        if (retry instanceof LeaderChangedException) {
            leaderChangedErrors.inc();
        }
        if (trialCount > maxTrials) {
            throw new HDBException("Too many trials (" + trialCount + "/" + maxTrials + ") for " + retry, retry);
        }
        if (retryError.isRequireMetadataRefresh()) {
            requestMetadataRefresh(retryError);
        }
    }
    try {
        // linear back-off
        Thread.sleep((trialCount + 1) * sleepTimeout);
    } catch (InterruptedException err) {
        Thread.currentThread().interrupt();
        throw new HDBException(err);
    }
}

Example 4 with LeaderChangedException

use of herddb.client.impl.LeaderChangedException in project herddb by diennea.

the class RoutedClientSideConnection method handleGenericError.

void handleGenericError(final Pdu reply, final long statementId, final boolean release) throws HDBException, ClientSideMetadataProviderException {
    boolean notLeader = PduCodec.ErrorResponse.readIsNotLeader(reply);
    boolean missingPreparedStatement = ErrorResponse.readIsMissingPreparedStatementError(reply);
    boolean sqlIntegrityViolation = ErrorResponse.readIsSqlIntegrityViolationError(reply);
    String msg = PduCodec.ErrorResponse.readError(reply);
    if (release) {
        reply.close();
    }
    if (notLeader) {
        throw new LeaderChangedException(msg);
    } else if (missingPreparedStatement) {
        LOGGER.log(Level.INFO, "Statement was flushed from server side cache " + msg);
        preparedStatements.invalidate(statementId);
        throw new RetryRequestException(msg);
    } else if (sqlIntegrityViolation) {
        LOGGER.log(Level.INFO, "SQLIntegrityViolationException: " + msg);
        throw new HDBException(msg, new SQLIntegrityConstraintViolationException(msg));
    } else {
        throw new HDBException(msg);
    }
}

Example 5 with LeaderChangedException

use of herddb.client.impl.LeaderChangedException in project herddb by diennea.

the class ClientMultiServerTest method testLeaderDetached.

@Test
public void testLeaderDetached() throws Exception {
    ServerConfiguration serverconfig_1 = newServerConfigurationWithAutoPort(folder.newFolder("server1").toPath());
    serverconfig_1.set(ServerConfiguration.PROPERTY_NODEID, "server1");
    serverconfig_1.set(ServerConfiguration.PROPERTY_MODE, ServerConfiguration.PROPERTY_MODE_CLUSTER);
    serverconfig_1.set(ServerConfiguration.PROPERTY_ZOOKEEPER_ADDRESS, testEnv.getAddress());
    serverconfig_1.set(ServerConfiguration.PROPERTY_ZOOKEEPER_PATH, testEnv.getPath());
    serverconfig_1.set(ServerConfiguration.PROPERTY_ZOOKEEPER_SESSIONTIMEOUT, testEnv.getTimeout());
    ServerConfiguration serverconfig_2 = serverconfig_1.copy().set(ServerConfiguration.PROPERTY_NODEID, "server2").set(ServerConfiguration.PROPERTY_BASEDIR, folder.newFolder("server2").toPath().toAbsolutePath());
    try (Server server_1 = new Server(serverconfig_1)) {
        server_1.start();
        server_1.waitForStandaloneBoot();
        Table table = Table.builder().name("t1").column("c", ColumnTypes.INTEGER).primaryKey("c").build();
        server_1.getManager().executeStatement(new CreateTableStatement(table), StatementEvaluationContext.DEFAULT_EVALUATION_CONTEXT(), TransactionContext.NO_TRANSACTION);
        server_1.getManager().executeUpdate(new InsertStatement(TableSpace.DEFAULT, "t1", RecordSerializer.makeRecord(table, "c", 1)), StatementEvaluationContext.DEFAULT_EVALUATION_CONTEXT(), TransactionContext.NO_TRANSACTION);
        server_1.getManager().executeUpdate(new InsertStatement(TableSpace.DEFAULT, "t1", RecordSerializer.makeRecord(table, "c", 2)), StatementEvaluationContext.DEFAULT_EVALUATION_CONTEXT(), TransactionContext.NO_TRANSACTION);
        try (Server server_2 = new Server(serverconfig_2)) {
            server_2.start();
            server_1.getManager().executeStatement(new AlterTableSpaceStatement(TableSpace.DEFAULT, new HashSet<>(Arrays.asList("server1", "server2")), "server1", 1, 0), StatementEvaluationContext.DEFAULT_EVALUATION_CONTEXT(), TransactionContext.NO_TRANSACTION);
            assertTrue(server_2.getManager().waitForTablespace(TableSpace.DEFAULT, 60000, false));
            server_2.getManager().setErrorIfNotLeader(false);
            // wait for data to arrive on server_2
            for (int i = 0; i < 100; i++) {
                GetResult found = server_2.getManager().get(new GetStatement(TableSpace.DEFAULT, "t1", Bytes.from_int(1), null, false), StatementEvaluationContext.DEFAULT_EVALUATION_CONTEXT(), TransactionContext.NO_TRANSACTION);
                if (found.found()) {
                    break;
                }
                Thread.sleep(100);
            }
            assertTrue(server_2.getManager().get(new GetStatement(TableSpace.DEFAULT, "t1", Bytes.from_int(1), null, false), StatementEvaluationContext.DEFAULT_EVALUATION_CONTEXT(), TransactionContext.NO_TRANSACTION).found());
            server_2.getManager().setErrorIfNotLeader(true);
            ClientConfiguration client_configuration = new ClientConfiguration(folder.newFolder().toPath());
            client_configuration.set(ClientConfiguration.PROPERTY_MODE, ServerConfiguration.PROPERTY_MODE_CLUSTER);
            client_configuration.set(ClientConfiguration.PROPERTY_ZOOKEEPER_ADDRESS, testEnv.getAddress());
            client_configuration.set(ClientConfiguration.PROPERTY_ZOOKEEPER_PATH, testEnv.getPath());
            client_configuration.set(ClientConfiguration.PROPERTY_ZOOKEEPER_SESSIONTIMEOUT, testEnv.getTimeout());
            try (HDBClient client = new HDBClient(client_configuration);
                HDBConnection connection = client.openConnection()) {
                try (ScanResultSet scan = connection.executeScan(TableSpace.DEFAULT, "SELECT * FROM t1 WHERE c=1", true, Collections.emptyList(), 0, 0, 10, true)) {
                    assertEquals(1, scan.consume().size());
                }
                // switch leader to server2
                server_2.getManager().executeStatement(new AlterTableSpaceStatement(TableSpace.DEFAULT, new HashSet<>(Arrays.asList("server1", "server2")), "server2", 1, 0), StatementEvaluationContext.DEFAULT_EVALUATION_CONTEXT(), TransactionContext.NO_TRANSACTION);
                // wait that server_1 leaves leadership
                for (int i = 0; i < 100; i++) {
                    TableSpaceManager tManager = server_1.getManager().getTableSpaceManager(TableSpace.DEFAULT);
                    if (tManager != null && !tManager.isLeader()) {
                        break;
                    }
                    Thread.sleep(100);
                }
                TableSpaceManager tManager = server_1.getManager().getTableSpaceManager(TableSpace.DEFAULT);
                assertTrue(tManager != null && !tManager.isLeader());
                // the client MUST automatically look for the new leader
                try (ScanResultSet scan = connection.executeScan(TableSpace.DEFAULT, "SELECT * FROM t1 WHERE c=1", true, Collections.emptyList(), 0, 0, 10, true)) {
                    assertEquals(1, scan.consume().size());
                }
            }
            // assert  that server_1 is not accepting request any more
            try (HDBClient client_to_1 = new HDBClient(new ClientConfiguration(folder.newFolder().toPath()));
                HDBConnection connection = client_to_1.openConnection()) {
                client_to_1.setClientSideMetadataProvider(new StaticClientSideMetadataProvider(server_1) {

                    @Override
                    public void requestMetadataRefresh(Exception error) throws ClientSideMetadataProviderException {
                        assertTrue(error instanceof LeaderChangedException);
                        throw new ClientSideMetadataProviderException(error);
                    }
                });
                try (ScanResultSet scan = connection.executeScan(TableSpace.DEFAULT, "SELECT * FROM t1 WHERE c=1", true, Collections.emptyList(), 0, 0, 10, true)) {
                    fail("server_1 MUST not accept queries");
                } catch (ClientSideMetadataProviderException ok) {
                    assertTrue(ok.getCause() instanceof LeaderChangedException);
                }
            }
            // assert that server_2 is accepting requests
            try (HDBClient client_to_2 = new HDBClient(new ClientConfiguration(folder.newFolder().toPath()));
                HDBConnection connection = client_to_2.openConnection()) {
                client_to_2.setClientSideMetadataProvider(new StaticClientSideMetadataProvider(server_2));
                try (ScanResultSet scan = connection.executeScan(TableSpace.DEFAULT, "SELECT * FROM t1 WHERE c=1", true, Collections.emptyList(), 0, 0, 10, true)) {
                    assertEquals(1, scan.consume().size());
                }
            }
        }
    }
}