Learn to Deploy Hyperledger Fabric v2.2 on Multihost

In this lecture, we discussed what is docker swarm, why to use it, and the architecture of the docker swarm.

Docker swarm is a container orchestration tool, meaning that it allows you to manage multiple containers deployed across multiple host machines. A swarm is a cluster of one or more physical or virtual machine running Docker.

One of the key benefits associated with the operation of a docker swarm is the high level of availability offered for applications.

Working of docker swarm

In a docker swarm, there are typically several worker nodes and at least one manager node that is responsible for handling the worker nodes' resources efficiently and ensuring that the cluster operates efficiently.

The manager node knows the status of the worker nodes in a cluster, and the worker nodes accept tasks sent from the manager node. Every worker node has an agent that reports on the state of the node's tasks to the manager. This way, the manager node can maintain the desired state of the cluster.

Features of docker swarm

• Decentralized access: Swarm makes it very easy for teams to access and manage the environment

• High security: Any communication between the manager and client nodes within the Swarm is highly secure

• Autoload balancing: There is autoload balancing within your environment, and you can script that into how you write out and structure the Swarm environment

• High scalability: Load balancing converts the Swarm environment into a highly scalable infrastructure

• Roll-back a task: Swarm allows you to roll back environments to previous safe environments

In this lecture, we discussed how we can create the manager and worker in our local system, we used a tool named Docker-Machine. Docker Machine is a tool for provisioning and managing your Dockerized hosts (hosts with Docker Engine on them).

We created 3 nodes (1 manager and 2 worker nodes) for our swarm cluster.

Before creating any node, please make sure that VirtualBox/HyperV is installed.

• Linux and OSX user need to install VirtualBox and windows user needs to enable HyperV for virtualization

• OSX users also need to enable permission for VirtualBox from the System Preference -> Security and Privacy.

• MacOS user can install VirtualBox using: brew install --cask virtualbox

• Linux users can install VirtualBox using:  sudo apt install virtualbox.

• Windows user can download VirtualBox from here: https://www.virtualbox.org/wiki/Downloads

if you find an error something like this docker-machine: Error with pre-create check: “exit status 126”

refer ->https://stackoverflow.com/questions/56091308/docker-machine-error-with-pre-create-check-in-windows

Create Docker machines

docker-machine create --driver hyperv manager1 or docker-machine create --driver virtualbox manager1

use command docker-machine ls to see all the nodes.

Commands used in the lecture

1. docker-machine create --driver virtualbox <nodeName>

2. docker-machine ls

3. docker-machine IP <nodeName>

   
   

FAQs & Helpful Tips:

1. A swarm is a group of machines that are running Docker and joined into a cluster

2. A cluster is managed by a swarm manager The machines in a swarm can be physical or virtual.

3. After joining a swarm, they are referred to as nodes Swarm managers are the only machines in a swarm that can execute your commands, or authorize other machines to join the swarm as workers

4. Workers are just there to provide capacity and do not have the authority to tell any other machine what it can and cannot do you can have a node join as a worker or as a manager.

5. At any point in time, there is only one LEADER and the other manager nodes will be as a backup in case the current LEADER opts out