Skip to content

Latest commit

 

History

History
42 lines (32 loc) · 1.66 KB

09_disposability.md

File metadata and controls

42 lines (32 loc) · 1.66 KB
Raw

9 - Disposability

Each process of an application must be disposable.

  • it must have a quick startup
    • ease the horizontal scalability
  • it must ensure a clean shutdown
    • stop listening on the port
    • finish to handle the current request
    • usage of a queueing system for long lasting (worker type) process

What does that mean for our application ?

Our application exposes HTTP endPoints that are easy and quick to handle. If we were to have some long lasting worker processes, the usage of a queueing system, like Apache Kafka, would be a great choice.

Kafka stores indexes of events processed by each worker. When a worker is restared, it can provide an index indicating at which point in time it needs to restart the event handling. Doing so no events are lost.

Docker Store offers several image of Kafka (Spotify, Wurstmeister, ...) that can easily be integrated in the docker-compose file of the application.

Below is an example of how Kafka (and zookeeper) could be added to our docker-compose file. Of course, this means the application has been slightly changed to be able to write and read to/from Kafka.

# Kafka message broker
zookeeper:
  image: wurstmeister/zookeeper
  ports:
    - "2181:2181"
kafka:
  image: wurstmeister/kafka
  ports:
    - "9092:9092"
  links:
    - zookeeper:zk
  environment:
    KAFKA_ADVERTISED_HOST_NAME: 192.168.99.100
    KAFKA_CREATE_TOPICS: "DATA:1:1"
  volumes:
    - /var/run/docker.sock:/var/run/docker.sock

Previous - Next