This microservice sends messages from Kafka topics to Elasticsearch indices. The topics should use the serialisation of JSON Event Sourcing. If a message contains the field _id then this is also used as the identifier in the index. Otherwise a random UUID is generated.
The configuration is managed by the
Lightbend Config package. By default it will try to load conf/application.conf. An alternative configuration may be loaded by adding -Dconfig.resource=myconfig.conf, where the file is also supposed to be in the conf directory. The following entries are available.
| Entry | Description |
|---|---|
| elastic.authorizationHeader | The value for the HTTP Authorization header. |
| elastic.uri | The root URI for uploading indices in Elasticsearch |
| environment | The name of the environment, e.g. "tst", "prd". |
| indices | This is an object where the keys are Kafka topics and the values are Elastic indices. |
| kafka | All Kafka settings come below this entry. So for example, the setting bootstrap.servers would go to the entry kafka.bootstrap.servers. |
| kafka.num.stream.threads | The number of worker threads per instance. |
| kafka.replication.factor | When using Confluent Cloud this should be 3. |
| logLevel | The log level as defined in java.util.logging.Level. |
| logTopic | The Kafka topic where the errors will be logged in the Elastic Common Schema. |
You can build the tool with mvn clean package. This will produce a self-contained JAR-file in the target directory with the form pincette-jes-indexer-<version>-jar-with-dependencies.jar. You can launch this JAR with java -jar, without further options.
The total number of threads across all the instances should not exceed the number of partitions for the Kafka topics. Additional threads will be idle.
You can run the JVM with the option -mx128m.
Docker images can be found at https://hub.docker.com/repository/docker/jsoneventsourcing/pincette-jes-indexer. You should add a configuration layer with a Docker file that looks like this:
FROM registry.hub.docker.com/jsoneventsourcing/pincette-jes-indexer:<version>
COPY conf/tst.conf /conf/application.conf
So wherever your configuration file comes from, it should always end up at /conf/application.conf.