Chapter 7. Camel Quarkus transaction guide

7.1. About the transaction guide

This guide provides information and instructions for implementing transactional applications with Red Hat build of Apache Camel for Quarkus.

7.2. JTA dependencies

In order to use camel-quarkus-jta, you need to include the following dependency in your pom.xml

<dependency>
  <groupId>org.apache.camel.quarkus</groupId>
  <artifactId>camel-quarkus-jta</artifactId>
</dependency>

This leverages quarkus-narayana-jta to provide JTA support in Camel.

7.2.1. Important configurations

There are some important quarkus.transaction-manager configurations you need to be aware of:

Configuration Default value Description Comment

Configuration	Default value	Description	Comment
`.node-name`	`quarkus`	Identifes the node. It needs to be unique and stable over both transaction manager and container restarts.	For more information, see Configuring transaction node name identifier in the Quarkus documentation.
`.object-store.type`	`file-system`	Configures where the transaction logs are stored - either in a directory (`file-system`) or in a database (`jdbc`).	For a cloud environment without access to persistent volumes, consider using the jdbc object store. For more information, see Configure storing of Quarkus transaction logs in a database section in the Quarkus documentation
`.enable-recovery`	`false`	Enables recovery of pending transactions in case of a JVM crash or shutdown.	We recommend that you set it to `true` when you are using XA transactions in your application. Otherwise, pending transactions are lost in case of a JVM crash or shutdown.

.node-name

quarkus

Identifes the node. It needs to be unique and stable over both transaction manager and container restarts.

For more information, see Configuring transaction node name identifier in the Quarkus documentation.

.object-store.type

file-system

Configures where the transaction logs are stored - either in a directory (file-system) or in a database (jdbc).

For a cloud environment without access to persistent volumes, consider using the jdbc object store.

For more information, see Configure storing of Quarkus transaction logs in a database section in the Quarkus documentation

.enable-recovery

false

Enables recovery of pending transactions in case of a JVM crash or shutdown.

We recommend that you set it to true when you are using XA transactions in your application. Otherwise, pending transactions are lost in case of a JVM crash or shutdown.

Additional resources

For more details, see the Quarkus Transaction Guide.

7.3. Configuring transactional resources

7.3.1. JDBC Datasource configuration

To configure the datasource:

Include the relevant jdbc extension by following the Configure datasources in Quarkus section in the Quarkus datasource guide.

The extensions are integrated with the Quarkus agroal extension to support pooling and XA transactions.

Optional

If you want to use the datasource in a XA transaction, you must enable it:
quarkus.datasource.jdbc.transactions = xa
quarkus.datasource.<datasource-name>.jdbc.transactions = xa
For more information, refer to the Narayana transaction manager integration section in the Quarkus datasource guide.

Warning

Do not mix using non-XA and XA datasource in a transaction.

It is not a transaction safe.

7.3.2. JMS Configuration

In order to use JMS with distributed transactions, you must do the the following:

Use quarkus-pooled-jms to support pooling and transaction, by including the following dependency in your pom.xml:

<dependency>
    <groupId>io.quarkiverse.messaginghub</groupId>
    <artifactId>quarkus-pooled-jms</artifactId>
</dependency>

Enable XA support by setting .transaction to xa:
quarkus.pooled-jms.transaction = xa

For more details, see Support for connection pooling and X/Open XA distributed transactions in the JMS extension documentation.

7.4. Examples

JPA and JMS

We use Narayana as the standalone JTA Transaction Manager implementation, and Hibernate as the JPA Adapter.

JMS and JPA: A Camel Quarkus example

Message Bridge

A basic REST endpoint is provided for users to dispatch a message to the IBM MQ queue. Messages from the IBM MQ are relayed to an ActiveMQ queue within an XA transaction. This example showcases the transaction functionality with rollback and recovery.

Message Bridge: A Camel Quarkus example

7.5. Transaction policies

There are six transaction policies:

Policy	Description	Comment
`PROPAGATION_MANDATORY`	Support a current transaction; throw an exception if no current transaction exists.
`PROPAGATION_NEVER`	Do not support a current transaction; throw an exception if a current transaction exists.
`PROPAGATION_NOT_SUPPORTED`	Do not support a current transaction; rather always execute non-transactionally.
`PROPAGATION_REQUIRED`	Support a current transaction; create a new one if none exists.	Default
`PROPAGATION_REQUIRES_NEW`	Create a new transaction, suspending the current transaction if one exists.
`PROPAGATION_SUPPORTS`	Support a current transaction; execute non-transactionally if none exists.

For more details, see Using different transaction propagations in the Quarkus Transactional client documentation.

7.6. Known issues

7.6.1. Non-XA datasource compatibility

Since 3.8.4, there is a compatibility break issue when using non-XA datasource. For more information see the pull request 40365

此内容没有您所选择的语言版本。