Chapter 7. Running a Camel service on Spring Boot with XA transactions

Procedure

1. This is a sample application.properties file. Replace the following options in the Kubernetes yaml descriptor.

   # Cluster
   cluster.nodename=1
   cluster.base-dir=./target/tx
   
   # Transaction Data
   spring.jta.transaction-manager-id=${cluster.nodename}
   spring.jta.log-dir=${cluster.base-dir}/store/${cluster.nodename}
   
   # Narayana recovery settings
   snowdrop.narayana.openshift.recovery.enabled=true
   snowdrop.narayana.openshift.recovery.current-pod-name=${cluster.nodename}
   # You must enable resource filtering in order to inject the Maven artifactId
   snowdrop.narayana.openshift.recovery.statefulset=${project.artifactId}
   snowdrop.narayana.openshift.recovery.status-dir=${cluster.base-dir}/status

2. You need a shared volume to store both transactions and information related to termination. It can be mounted in the StatefulSet yaml descriptor as follows.

   apiVersion: apps/v1beta1
   kind: StatefulSet
   #...
   spec:
   #...
     template:
   #...
       spec:
         containers:
         - env:
           - name: CLUSTER_BASE_DIR
             value: /var/transaction/data
             # Override CLUSTER_NODENAME with Kubernetes Downward API (to use `pod-0`, `pod-1` etc. as tx manager id)
           - name: CLUSTER_NODENAME
             valueFrom:
               fieldRef:
                 apiVersion: v1
                 fieldPath: metadata.name
   #...
           volumeMounts:
           - mountPath: /var/transaction/data
             name: the-name-of-the-shared-volume
   #...

Procedure

1. Download Camel Spring Boot XA project.

   git clone --branch spring-boot-camel-xa-1.0.0.fuse-750020-redhat-00005 https://github.com/jboss-fuse/spring-boot-camel-xa

2. Navigate to spring-boot-camel-xa directory and run following command.

   mvn clean install

3. Log in to the OpenShift Server.

   oc login -u developer -p developer

4. Create a new project namespace called test (assuming it does not already exist).

   oc new-project test

   If the test project namespace already exists, switch to it.

   oc project test

5. Install dependencies.

   • Install postgresql using username as theuser and password as Thepassword1!.

     oc new-app --param=POSTGRESQL_USER=theuser --param=POSTGRESQL_PASSWORD='Thepassword1!' --env=POSTGRESQL_MAX_PREPARED_TRANSACTIONS=100 --template=postgresql-persistent

   • Install the A-MQ broker using username as theuser and password as Thepassword1!.

     oc new-app --param=MQ_USERNAME=theuser --param=MQ_PASSWORD='Thepassword1!' --template=amq63-persistent

6. Create a persistent volume claim for the transaction log.

   oc create -f persistent-volume-claim.yml

7. Build and deploy your quickstart.

   mvn fabric8:deploy -P openshift

8. Scale it up to the desired number of replicas.

   oc scale statefulset spring-boot-camel-xa --replicas 3

   Note: The pod name is used as transaction manager id (spring.jta.transaction-manager-id property). The current implementation also limits the length of transaction manager ids. So please note that:

   • The name of the StatefulSet is an identifier for the transaction system, so it must not be changed.
   • You should name the StatefulSet so that all of its pod names have length lower than or equal to 23 characters. Pod names are created by OpenShift using the convention: <statefulset-name>-0, <statefulset-name>-1 and so on. Narayana does its best to avoid having multiple recovery managers with the same id, so when the pod name is longer than the limit, the last 23 bytes are taken as transaction manager id (after stripping some characters like -).

9. Once the quickstart is running, get the base service URL using the following command.

   NARAYANA_HOST=$(oc get route spring-boot-camel-xa -o jsonpath={.spec.host})

Procedure

1. Get the list of messages in the audit_log table.

   curl -w "\n" http://$NARAYANA_HOST/api/

2. The list is empty at the beginning. Now you can put the first element.

   curl -w "\n" -X POST http://$NARAYANA_HOST/api/?entry=hello

   After waiting for some time get the new list.

   curl -w "\n" http://$NARAYANA_HOST/api/

3. The new list contains two messages, hello and hello-ok. The hello-ok confirms that the message has been sent to a outgoing queue and then logged. You can add multiple messages and see the logs.

Procedure

1. Send a message named fail.

   curl -w "\n" -X POST http://$NARAYANA_HOST/api/?entry=fail

2. After waiting for some time get the new list.

   curl -w "\n" http://$NARAYANA_HOST/api/

3. This message produces an exception at the end of the route, so that the transaction is always rolled back. You should not find any trace of the message in the audit_log table.