/**
* Database-independent synchronization strategy that does full record transfer between two
* databases. This strategy is best used when there are <em>many</em> differences between the active
* database and the inactive database (i.e. very much out of sync). The following algorithm is used:
*
* <ol>
* <li>Drop the foreign keys on the inactive database (to avoid integrity constraint violations)
* <li>For each database table:
* <ol>
* <li>Delete all rows in the inactive database table
* <li>Query all rows on the active database table
* <li>For each row in active database table:
* <ol>
* <li>Insert new row into inactive database table
* </ol>
* </ol>
* <li>Re-create the foreign keys on the inactive database
* <li>Synchronize sequences
* </ol>
*
* @author Paul Ferraro
*/
public class FullSynchronizationStrategy
implements SynchronizationStrategy, TableSynchronizationStrategy, Serializable {
private static final long serialVersionUID = 9190347092842178162L;
private static Logger logger = LoggerFactory.getLogger(FullSynchronizationStrategy.class);
private SynchronizationStrategy strategy = new PerTableSynchronizationStrategy(this);
private int maxBatchSize = 100;
private int fetchSize = 0;
@Override
public String getId() {
return "full";
}
@Override
public <Z, D extends Database<Z>> void init(DatabaseCluster<Z, D> cluster) {
this.strategy.init(cluster);
}
@Override
public <Z, D extends Database<Z>> void synchronize(SynchronizationContext<Z, D> context)
throws SQLException {
this.strategy.synchronize(context);
}
@Override
public <Z, D extends Database<Z>> void destroy(DatabaseCluster<Z, D> cluster) {
this.strategy.destroy(cluster);
}
@Override
public <Z, D extends Database<Z>> void synchronize(
SynchronizationContext<Z, D> context, TableProperties table) throws SQLException {
final String tableName = table.getName().getDMLName();
final Collection<String> columns = table.getColumns();
final String commaDelimitedColumns = Strings.join(columns, Strings.PADDED_COMMA);
final String selectSQL = String.format("SELECT %s FROM %s", commaDelimitedColumns, tableName);
final String deleteSQL = context.getDialect().getTruncateTableSQL(table);
final String insertSQL =
String.format(
"INSERT INTO %s (%s) VALUES (%s)",
tableName,
commaDelimitedColumns,
Strings.join(
Collections.nCopies(columns.size(), Strings.QUESTION), Strings.PADDED_COMMA));
Connection sourceConnection = context.getConnection(context.getSourceDatabase());
final Statement selectStatement = sourceConnection.createStatement();
try {
selectStatement.setFetchSize(this.fetchSize);
Callable<ResultSet> callable =
new Callable<ResultSet>() {
@Override
public ResultSet call() throws SQLException {
logger.log(Level.DEBUG, selectSQL);
return selectStatement.executeQuery(selectSQL);
}
};
Future<ResultSet> future = context.getExecutor().submit(callable);
Connection targetConnection = context.getConnection(context.getTargetDatabase());
Statement deleteStatement = targetConnection.createStatement();
try {
logger.log(Level.DEBUG, deleteSQL);
int deletedRows = deleteStatement.executeUpdate(deleteSQL);
logger.log(Level.INFO, Messages.DELETE_COUNT.getMessage(), deletedRows, tableName);
} finally {
Resources.close(deleteStatement);
}
logger.log(Level.DEBUG, insertSQL);
PreparedStatement insertStatement = targetConnection.prepareStatement(insertSQL);
try {
int statementCount = 0;
ResultSet resultSet = future.get();
while (resultSet.next()) {
int index = 0;
for (String column : table.getColumns()) {
index += 1;
int type = context.getDialect().getColumnType(table.getColumnProperties(column));
Object object = context.getSynchronizationSupport().getObject(resultSet, index, type);
if (resultSet.wasNull()) {
insertStatement.setNull(index, type);
} else {
insertStatement.setObject(index, object, type);
}
}
insertStatement.addBatch();
statementCount += 1;
if ((statementCount % this.maxBatchSize) == 0) {
insertStatement.executeBatch();
insertStatement.clearBatch();
}
insertStatement.clearParameters();
}
if ((statementCount % this.maxBatchSize) > 0) {
insertStatement.executeBatch();
}
logger.log(Level.INFO, Messages.INSERT_COUNT.getMessage(), statementCount, table);
} catch (ExecutionException e) {
throw ExceptionType.getExceptionFactory(SQLException.class).createException(e.getCause());
} catch (InterruptedException e) {
Thread.currentThread().interrupt();
throw new SQLException(e);
} finally {
Resources.close(insertStatement);
}
} finally {
Resources.close(selectStatement);
}
}
@Override
public <Z, D extends Database<Z>> void dropConstraints(SynchronizationContext<Z, D> context)
throws SQLException {
context.getSynchronizationSupport().dropForeignKeys();
}
@Override
public <Z, D extends Database<Z>> void restoreConstraints(SynchronizationContext<Z, D> context)
throws SQLException {
context.getSynchronizationSupport().restoreForeignKeys();
}
/** @return the fetchSize. */
public int getFetchSize() {
return this.fetchSize;
}
/** @param fetchSize the fetchSize to set. */
public void setFetchSize(int fetchSize) {
this.fetchSize = fetchSize;
}
/** @return the maxBatchSize. */
public int getMaxBatchSize() {
return this.maxBatchSize;
}
/** @param maxBatchSize the maxBatchSize to set. */
public void setMaxBatchSize(int maxBatchSize) {
this.maxBatchSize = maxBatchSize;
}
}
/** @author Paul Ferraro */
public class SQLStateManagerFactory extends GenericObjectPoolConfiguration
implements StateManagerFactory {
private static final long serialVersionUID = -544548607415128414L;
private Logger logger = LoggerFactory.getLogger(this.getClass());
enum EmbeddedVendor {
H2("jdbc:h2:{1}/{0}"),
HSQLDB("jdbc:hsqldb:{1}/{0}"),
DERBY("jdbc:derby:{1}/{0};create=true");
final String pattern;
EmbeddedVendor(String pattern) {
this.pattern = pattern;
}
}
private String urlPattern = this.defaultUrlPattern();
private String user;
private String password;
private String defaultUrlPattern() {
for (EmbeddedVendor vendor : EmbeddedVendor.values()) {
String url = MessageFormat.format(vendor.pattern, "test", Strings.HA_JDBC_HOME);
try {
for (Driver driver : Collections.list(DriverManager.getDrivers())) {
if (driver.acceptsURL(url)) {
return vendor.pattern;
}
}
} catch (SQLException e) {
// Skip vendor
}
}
return null;
}
@Override
public String getId() {
return "sql";
}
/**
* {@inheritDoc}
*
* @see net.sf.hajdbc.state.StateManagerFactory#createStateManager(net.sf.hajdbc.DatabaseCluster)
*/
@Override
public <Z, D extends Database<Z>> StateManager createStateManager(DatabaseCluster<Z, D> cluster) {
if (this.urlPattern == null) {
throw new IllegalArgumentException(
"No embedded database driver was detected on the classpath.");
}
String url = MessageFormat.format(this.urlPattern, cluster.getId(), Strings.HA_JDBC_HOME);
DriverDatabase database = new DriverDatabase();
database.setLocation(url);
database.setUser(this.user);
database.setPassword(this.password);
this.logger.log(
Level.INFO, "State for database cluster {0} will be persisted to {1}", cluster, url);
return new SQLStateManager<Z, D>(cluster, database, new GenericObjectPoolFactory(this));
}
public String getUrlPattern() {
return this.urlPattern;
}
public void setUrlPattern(String urlPattern) {
this.urlPattern = urlPattern;
}
public String getUser() {
return this.user;
}
public void setUser(String user) {
this.user = user;
}
public String getPassword() {
return this.password;
}
public void setPassword(String password) {
this.password = password;
}
}
/** @author Paul Ferraro */
public class LifecycleRegistry<K, V extends Lifecycle, C, E extends Exception>
implements Registry<K, V, C, E> {
private final Logger logger = LoggerFactory.getLogger(this.getClass());
private final LifecycleRegistry.Store<K, RegistryEntry> store;
final Factory<K, V, C, E> factory;
final ExceptionFactory<E> exceptionFactory;
public LifecycleRegistry(
Factory<K, V, C, E> factory,
RegistryStoreFactory<K> storeFactory,
ExceptionFactory<E> exceptionFactory) {
this.store = storeFactory.createStore();
this.factory = factory;
this.exceptionFactory = exceptionFactory;
}
/**
* {@inheritDoc}
*
* @see net.sf.hajdbc.util.concurrent.Registry#get(java.lang.Object, java.lang.Object)
*/
@Override
public V get(K key, C context) throws E {
RegistryEntry entry = this.store.get(key);
if (entry != null) {
return entry.getValue();
}
V value = this.factory.create(key, context);
entry = new RegistryEntry(value);
RegistryEntry existing = this.store.setIfAbsent(key, entry);
if (existing != null) {
return existing.getValue();
}
try {
value.start();
entry.started();
return value;
} catch (Exception e) {
this.store.clear(key);
try {
value.stop();
} catch (Exception re) {
this.logger.log(Level.INFO, re);
}
throw this.exceptionFactory.createException(e);
}
}
/**
* {@inheritDoc}
*
* @see net.sf.hajdbc.util.concurrent.Registry#remove(java.lang.Object)
*/
@Override
public void remove(K key) throws E {
RegistryEntry entry = this.store.clear(key);
if (entry != null) {
entry.getValue().stop();
}
}
private class RegistryEntry {
private final V value;
private final AtomicReference<CountDownLatch> latchRef =
new AtomicReference<CountDownLatch>(new CountDownLatch(1));
RegistryEntry(V value) {
this.value = value;
}
V getValue() throws E {
CountDownLatch latch = this.latchRef.get();
if (latch != null) {
try {
if (!latch.await(
LifecycleRegistry.this.factory.getTimeout(),
LifecycleRegistry.this.factory.getTimeoutUnit())) {
throw LifecycleRegistry.this.exceptionFactory.createException(new TimeoutException());
}
} catch (InterruptedException e) {
Thread.currentThread().interrupt();
throw LifecycleRegistry.this.exceptionFactory.createException(e);
}
}
return this.value;
}
void started() {
CountDownLatch latch = this.latchRef.getAndSet(null);
if (latch != null) {
latch.countDown();
}
}
}
}
