Book Image

Docker High Performance. - Second Edition

By : Allan Espinosa, Russ McKendrick
Book Image

Docker High Performance. - Second Edition

By: Allan Espinosa, Russ McKendrick

Overview of this book

Docker is an enterprise-grade container platform that allows you to build and deploy your apps. Its portable format lets you run your code right from your desktop workstations to popular cloud computing providers. This comprehensive guide will improve your Docker work?ows and ensure your application's production environment runs smoothly. This book starts with a refresher on setting up and running Docker and details the basic setup for creating a Docker Swarm cluster. You will then learn how to automate this cluster by using the Chef server and cookbooks. After that, you will run the Docker monitoring system with Prometheus and Grafana, and deploy the ELK stack. You will also learn best practices for optimizing Docker images. After deploying containers with the help of Jenkins, you will then move on to a tutorial on using Apache JMeter to analyze your application's performance. You will learn how to use Docker Swarm and NGINX to load-balance your application, and how common debugging tools in Linux can be used to troubleshoot Docker containers. By the end of this book, you will be able to integrate all the optimizations that you have learned and put everything into practice in your applications.
Table of Contents (16 chapters)
Title Page
Copyright and Credits
About Packt
Contributors
Preface
Index

Scaling out our Docker applications


Now, suppose that the workload in the previous section starts to overload each of our three Docker hosts. Without a load balancer such as our preceding NGINX setup, our application's performance will start to degrade. This may mean a lower quality of service to our application's users or being paged in the middle of the night to perform heroic systems operations. However, with a load balancer managing the connections to our applications, it is very simple to add more capacity to scale out the performance of our application.

As our application is already designed to be load balanced, our scale-out process is very simple. The only thing we need to do is update the number of replicas of our application in the compose-lb.yml file:

---
version: '3.7'

services:
  nginx:
    image: nginx:stable
    ports:
      - '80:80'
    configs:
      - source: nginx.conf
        target: /etc/nginx/nginx.conf
  app_green:
    image: hubuser/app:1.0.0
    deploy:
      replicas...