workflow-graph-node

Workflow Graph Node

Description

The generic component for workflow graph that allows the execution of workflows from an incoming event stream. In addition to running the workflows, the responsibilities of this component also include shepherding them to completion and producing output to another message queue.

Technology

• Java 11 on GraalVM
• Spring Boot
  • Webflux
• RabbitMQ
• Reactor
• Reactor-RabbitMQ-Streams
• Avro
• Apollo GraphQL

Building

mvn clean package

Running

mvn spring-boot:run

Logging

Handled with log4j2, currently with two possible configs; the default just outputs to standard out/err based on log level, the log4j2-kafka.xml config is enabled via the kafka profile and includes the required config to send logs to Kafka via the Kafka Log Appender. The log config has 4 properties that can be set via env and comes with sensible defaults already configured.

Kafka logging env variables:

• LOG4J2_GRAPH_LOG_MARKER (default: GraphLog) - the org.slf4j.Marker used to identify logs meant for Kafka
• LOG4J2_KAFKA_BROKERS (default: localhost:9092) - Kafka brokers
• LOG4J2_KAFKA_INFO_DEBUG_TOPIC (default: graphlog_info_debug) - topic to send logs of level INFO and below
• LOG4J2_KAFKA_ERROR_WARNING_TOPIC (default: graphlog_error_warning) - topic to send logs of WARNING and above

Logs sent to Kafka are in JSON format corresponding to the out of the toJSON() method of the GraphLog class

Design