jta-jpa

JTA and JPA: A Camel Quarkus example

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

This example will connect to a database with the connection details defined in application.properties. If the example is run on Development mode and no database exists, Quarkus will create a matching database as described here.

Tip	Check the Camel Quarkus User guide for prerequisites and other general information.

Note	The Narayana node.identifier is very important when you scale up in the cloud environment. It must be unique for each node. You can set it by using quarkus.transaction-manager.node-name property which the default value is quarkus.

Start in the Development mode

$ mvn clean compile quarkus:dev

The above command compiles the project, starts the application and lets the Quarkus tooling watch for changes in your workspace. Any modifications in your project will automatically take effect in the running application.

Tip	Please refer to the Development mode section of Camel Quarkus User guide for more details.

Package and run the application

Once you are done with developing you may want to package and run the application.

Tip	Find more details about the JVM mode and Native mode in the Package and run section of Camel Quarkus User guide

External systems

Start MySQL:

docker run --name db-mysql \
  -e MYSQL_ROOT_PASSWORD=root \
  -d -p 3306:3306 mysql

docker exec -it db-mysql mysql -uroot -proot -e \
  "CREATE DATABASE testdb CHARACTER SET utf8mb4;
   CREATE USER 'admin'@'%' IDENTIFIED WITH mysql_native_password BY 'admin';
   GRANT ALL ON testdb.* TO 'admin'@'%';
   GRANT XA_RECOVER_ADMIN on *.* to 'admin'@'%';
   FLUSH PRIVILEGES;"

Create audit_log if it is needed:

docker exec -it db-mysql mysql -uadmin -padmin testdb -e \
  "CREATE TABLE audit_log ( \
      id bigint NOT NULL AUTO_INCREMENT, \
      message varchar(255) DEFAULT NULL, \
      PRIMARY KEY (id) \
  );"

Prerequisites

• Make sure io.quarkus:quarkus-jdbc-mysql has been added in pom.xml

• Make sure db-mysql has been started and ready for servicing

• Edit src/main/resource/application.properties to uncomment all %prod lines

# Production Datasource
%prod.quarkus.datasource.db-kind=mysql
%prod.quarkus.datasource.username=admin
%prod.quarkus.datasource.password=admin
%prod.quarkus.datasource.jdbc.url=mysql://localhost:3306/testdb
%prod.quarkus.datasource.jdbc.transactions=xa

%prod.quarkus.hibernate-orm.database.generation=none

JVM mode

$ mvn clean package
$ java -jar target/quarkus-app/quarkus-run.jar
...

[io.quarkus] (main) camel-quarkus-examples-... started in 0.570s.

Native mode

Important

Native mode requires having GraalVM and other tools installed. Please check the Prerequisites section of Camel Quarkus User guide.

To prepare a native executable using GraalVM, run the following command:

$ mvn clean package -Pnative
$ ./target/*-runner
...
[io.quarkus] (main) camel-quarkus-examples-... started in 0.011s.
...

How to run

Test the service endpoint from another terminal:

ADDRESS="http://localhost:8080"
curl -X POST $ADDRESS/api/messages/hello
curl $ADDRESS/api/messages

Test with normal "hello" content:

curl -X POST $ADDRESS/api/messages/hello

Check the audit_log:

curl $ADDRESS/api/messages

You should get some results like:

[{message=hello}]

Test rollback by calling the service with "fail" content:

curl -X POST $ADDRESS/api/messages/fail

You should not find any trace of the message in the audit_log table. And some failures like:

2022-07-01 11:03:10,257 INFO  [route2] (executor-thread-0) Forced exception
2022-07-01 11:03:10,257 ERROR [org.apa.cam.pro.err.DefaultErrorHandler] (executor-thread-0) Failed delivery for (MessageId: 0BE5920FE20C353-0000000000000001 on ExchangeId: 0BE5920FE20C353-0000000000000001). Exhausted after delivery attempt: 1 caught: java.lang.RuntimeException: fail

Message History (source location and message history is disabled)
---------------------------------------------------------------------------------------------------------------------------------------
Source                                   ID                             Processor                                          Elapsed (ms)
                                         route5/route5                  from[platform-http:///api/messages/%7Bmessage%7D?h            4
	...
                                         route2/process1                Processor@0x60941009                                          0

Stacktrace
---------------------------------------------------------------------------------------------------------------------------------------: java.lang.RuntimeException: fail

Test crash recovery by calling the service with "crash" content:

curl -X POST $ADDRESS/api/messages/crash

The application should be crashed, and you can not see any response.

curl: (52) Empty reply from server

Now restart the application, and wait about 10 seconds, then you can see the following messages that the application has recovered the transaction.

2022-09-16 12:35:39,994 INFO  [io.quarkus] (main) camel-quarkus-examples-jta-jpa 2.13.0-SNAPSHOT on JVM (powered by Quarkus 2.13.0.CR1) started in 1.755s. Listening on: http://0.0.0.0:8080
2022-09-16 12:35:39,994 INFO  [io.quarkus] (main) Profile prod activated.
2022-09-16 12:35:39,994 INFO  [io.quarkus] (main) Installed features: [agroal, camel-attachments, camel-bean, camel-core, camel-direct, camel-jpa, camel-jta, camel-log, camel-microprofile-health, camel-platform-http, camel-rest, cdi, hibernate-orm, jdbc-h2, jdbc-mysql, narayana-jta, smallrye-context-propagation, smallrye-health, vertx]
2022-09-16 12:35:49,251 INFO  [org.acm.DummyXAResourceRecovery] (Periodic Recovery) DummyXAResourceRecovery returning list of resources: [org.acme.DummyXAResource@35cdbf7a]
2022-09-16 12:35:49,270 INFO  [org.acm.DummyXAResource] (Periodic Recovery) Committing DummyXAResource

check the audit_log table, you should see the message "crash" in the table.

Feedback

Please report bugs and propose improvements via GitHub issues of Camel Quarkus project.