The bootstrapper is the mechanism that is used to load stream config into cep. You can configure the boostrapper class on the config file, using bootstrapper.classname property. Currently, the cep has two bootstrappers:

Bootstrappers

Kafka Bootstrapper

io.wizzie.bootstrapper.bootstrappers.impl.KafkaBootstrapper

This bootstrapper read the stream config from Kafka, so you can change the stream topology without restart the service. The bootstrapper is reading the topic __cep_bootstrap using a kafka consumer instance with a random group.id.

Property	Description
bootstrap.kafka.topics	Topics that are used to read the bootstrapper configuration
application.id	The app id to identify the client configuration
bootstrap.servers	The kafka broker to read the bootstrapper configuration

StreamerKafkaConfig

The StreamerKafkaConfig tool allow us to send new stream config to the cep and read the current stream config.

You can use the script streamer-kafka.sh to use this tool. The tool has two modes:

Read Mode

The read mode allow us to read the current stream configuration to specific cep instance.

bin/streamer-kafka.sh $BOOTSTRAP_KAFKA_SERVER $APPLICATION_ID

Write Mode

The write mode allow us to send new stream configuration to specific cep instance.

bin/streamer-kafka.sh $BOOTSTRAP_KAFKA_SERVER $APPLICATION_ID $STREAM_CONFIG_FILE

Library: Bootstrapper

File Bootstrapper

io.wizzie.bootstrapper.bootstrappers.impl.FileBootstrapper

This bootstrapper read the stream config from local file system, and build a KS topology using this file. You need to add the properties on the configuration file.

Property	Description
file.bootstrapper.path	Stream config file path

Library: Bootstrapper