Distributed Transaction #

Scenarios

The DBPlusEngine distributed database solution provides support for distributed transactions, with commonly used modes being XA and BASE. Distributed transactions provide the semantics of final consistency. In XA mode, if the isolation level of storage DB is serializable, it can achieve strong consistency semantics. Here is how to use XA.

Prerequisites

Taking DBPlusEngine-Proxy as an example, start by downloading and unzipping the proxy. Refer to the following configuration, configure the corresponding configuration file in the conf directory and start the proxy.

Configuration Example

• Configuring with Atomikos

server.yaml

rules:
  - !TRANSACTION
    defaultType: XA
    providerType: Atomikos

• Configuring with Narayana

Because the Narayana configuration is complicated, DBPlusEngine-Proxy provides automatic configuration. Now users do not need to manually configure jbossts-properties.xml configuration file.

DBPlusEngine will automatically configure Narayana specified in server.yaml, and generate the corresponding jbossts-properties.xml configuration file.

server.yaml

rules:
 - !TRANSACTION
  defaultType: XA
  providerType: Narayana

When Narayana is used as the XA transaction manager and the DB mode is configured to store XA recovery information, the DBPlusEngine-Proxy supports transferring the unrecovered transactions on the failed proxy instance to other proxies for recovery.

The configuration is as follows:

  - !TRANSACTION
    defaultType: XA
    providerType: Narayana
    props:
      recoveryStoreUrl: jdbc:mysql://127.0.0.1:3306/jbossts?serverTimezone=UTC&useSSL=false&allowPublicKeyRetrieval=true
      # mysql8 using com.mysql.cj.jdbc.MysqlDataSource
      recoveryStoreDataSource: com.mysql.jdbc.jdbc2.optional.MysqlDataSource
      recoveryStoreUser: databaseUser
      recoveryStorePassword: databasePwd