Developing transactionally consistent consumer applications for the CDC Replication Engine for Kafka (UNIX and Linux)

You can include the transactionally consistent consumer in custom Java applications that work with the CDC Replication Engine for Kafka.

1. Extract the txnconsumer-applications-samples-*-sources.jar file into the /lib directory in your CDC Replication Engine for Kafka installation directory.

   cd CDC_Kafka_installation_directory/lib

   cat txnconsumer-applications-samples-*-sources.jar | jar -xv

2. Locate the sample transactionally consistent consumer applications in CDC_Kafka_installation_directory/lib/com/datamirror/ts/kafka/ and find an application that you want to use as a sample.
3. Rename the sample class and .java file so that they differ from the existing sample .java file.
4. Modify the .java file.
5. Compile the user-defined .java file.

   javac -classpath "CDC_Kafka_installation_directory/lib/*" CDC_Kafka_installation_directory/lib/com/datamirror/ts/kafka/txconsistentconsumer/sampleapplications/user-defined-application.java

6. Confirm that a .class file was created in the directory where the user-defined .java file resides.

   ls CDC_Kafka_installation_directory/lib/com/datamirror/ts/kafka/txconsistentconsumer/sampleapplications

   Note: The files that you generate from compiling the class must be in a library or folder that is referenced by the CLASSPATH environment variable.
7. Call the application from the /lib directory in your CDC Replication Engine for Kafka installation directory.

   cd CDC_Kafka_installation_directory/lib

   java -cp "*" com.datamirror.ts.kafka.txconsistentconsumer.sampleapplications.application name -cs commit stream topic name -c consumer configuration file name

   Note: Adding libraries to the CLASSPATH that conflict with libraries that are provided with the CDC Replication Engine for Kafka is not supported.