Distributed Transaction

Distributed transaction have been integrated into ShardingDataSource, you can use TransactionTypeHolder to modify transaction type before creating ShardingConnection.

XA

Introduce Maven Dependency

<dependency>
    <groupId>org.apache.shardingsphere</groupId>
    <artifactId>sharding-transaction-xa-core</artifactId>
    <version>${shardingsphere.version}</version>
</dependency>

Switch Transaction Type Based on Java

 TransactionTypeHolder.set(TransactionType.XA);

Atomikos Configuration (Optional)

Default ShardingSphere XA transaction manager is Atomikos. xa_tx.log generated in the project log is necessary for the recovery when XA crashes. Please do not delete it.

Or you can add jta.properties in classpath of the program to customize Atomikos configurations. For detailed configuration rules, please refer to the official documentation of Atomikos.

BASE Transaction

Currently, we have integrated saga and seata into shardingsphere.

Introduce Maven Dependency

<!-- saga transaction -->
<dependency>
    <groupId>io.shardingsphere</groupId>
    <artifactId>sharding-transaction-base-saga</artifactId>
    <version>${shardingsphere-spi-impl.version}</version>
</dependency>

${shardingsphere-spi-impl.version} mentioned has not been posted to the central maven repository, so you need to install it by yourself.

<!-- seata at transaction -->
<dependency>
    <groupId>org.apache.shardingsphere</groupId>
    <artifactId>sharding-transaction-base-seata-at</artifactId>
    <version>${sharding-sphere.version}</version>
</dependency>

Switch Transaction Type Based on Java

 TransactionTypeHolder.set(TransactionType.BASE);

Saga Configuration

You can add saga.properties in the project classpath to customize Saga configurations. When saga.persistence.enabled=true, Saga engine will persist event log through JDBC.
Configuration properties and explanations are as follow:

Property Default Value Explanation
saga.actuator.executor.size 5 Saga actuator thread pool size
saga.actuator.transaction.max.retries 5 Maximum retry times
saga.actuator.compensation.max.retries 5 Maximum compensation times
saga.actuator.transaction.retry.delay.milliseconds 5000 Retry interval
saga.actuator.compensation.retry.delay.milliseconds 3000 Compensation interval
saga.persistence.enabled false Persistence for event log
saga.persistence.ds.url No JDBC url
saga.persistence.ds.username No User name
saga.persistence.ds.password No Password
saga.persistence.ds.max.pool.size 50 Maximum connection
saga.persistence.ds.min.pool.size 1 Minimum connection
saga.persistence.ds.max.life.time.milliseconds 0 (unrestricted) Maximum life time (millisecond)
saga.persistence.ds.idle.timeout.milliseconds 60 * 1000 Idle timeout (millisecond)
saga.persistence.ds.connection.timeout.milliseconds 30 * 1000 Connection timeout (millisecond)

Saga event log table structure

-- MySQL init table SQL

CREATE TABLE IF NOT EXISTS saga_event(
  id BIGINT AUTO_INCREMENT PRIMARY KEY,
  saga_id VARCHAR(255) null,
  type VARCHAR(255) null,
  content_json TEXT null,
  create_time TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
  INDEX saga_id_index(saga_id)
)ENGINE=InnoDB DEFAULT CHARSET=utf8

saga_event table will be created automatically when your put this DDL into schema-init.sql located in classpath.

Seata Configuration

1.Download seata server according to seata-work-shop, refer to step6 and step7 is OK.

2.Create undo_log table in each physical database.(only mysql supported before seata version 0.8.X)

CREATE TABLE IF NOT EXISTS `undo_log` (
  `id` bigint(20) NOT NULL AUTO_INCREMENT,
  `branch_id` bigint(20) NOT NULL,
  `xid` varchar(100) NOT NULL,
  `rollback_info` longblob NOT NULL,
  `log_status` int(11) NOT NULL,
  `log_created` datetime NOT NULL,
  `log_modified` datetime NOT NULL,
  `ext` varchar(100) DEFAULT NULL,
  PRIMARY KEY (`id`),
  UNIQUE KEY `ux_undo_log` (`xid`,`branch_id`)
) ENGINE=InnoDB AUTO_INCREMENT=1 DEFAULT CHARSET=utf8;

3.Config seata.conf file in classpath.

client {
    application.id = raw-jdbc   ## application unique id.
    transaction.service.group = raw-jdbc-group   ## transaction group
}

Distributed Transaction Example