Docker Compose for Single and Multi Node Cassandra Example

You can use examples below to create a single and multi node Cassandra clusters.

Single Node

version: "3.7"

services:

  blog-cassandra:
    image: "cassandra:3.11.9"
    container_name: "blog-cassandra"
    ports:
      - "9042:9042"
    environment:
      - "MAX_HEAP_SIZE=256M"
      - "HEAP_NEWSIZE=128M"

#cassandra #docker

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Docker Compose for Single and Multi Node Cassandra Example

You can use examples below to create a single and multi node Cassandra clusters.

Single Node

version: "3.7"

services:

  blog-cassandra:
    image: "cassandra:3.11.9"
    container_name: "blog-cassandra"
    ports:
      - "9042:9042"
    environment:
      - "MAX_HEAP_SIZE=256M"
      - "HEAP_NEWSIZE=128M"

#cassandra #docker

Multi-cloud Spending: 8 Tips To Lower Cost

A multi-cloud approach is nothing but leveraging two or more cloud platforms for meeting the various business requirements of an enterprise. The multi-cloud IT environment incorporates different clouds from multiple vendors and negates the dependence on a single public cloud service provider. Thus enterprises can choose specific services from multiple public clouds and reap the benefits of each.

Given its affordability and agility, most enterprises opt for a multi-cloud approach in cloud computing now. A 2018 survey on the public cloud services market points out that 81% of the respondents use services from two or more providers. Subsequently, the cloud computing services market has reported incredible growth in recent times. The worldwide public cloud services market is all set to reach $500 billion in the next four years, according to IDC.

By choosing multi-cloud solutions strategically, enterprises can optimize the benefits of cloud computing and aim for some key competitive advantages. They can avoid the lengthy and cumbersome processes involved in buying, installing and testing high-priced systems. The IaaS and PaaS solutions have become a windfall for the enterprise’s budget as it does not incur huge up-front capital expenditure.

However, cost optimization is still a challenge while facilitating a multi-cloud environment and a large number of enterprises end up overpaying with or without realizing it. The below-mentioned tips would help you ensure the money is spent wisely on cloud computing services.

• Deactivate underused or unattached resources

Most organizations tend to get wrong with simple things which turn out to be the root cause for needless spending and resource wastage. The first step to cost optimization in your cloud strategy is to identify underutilized resources that you have been paying for.

Enterprises often continue to pay for resources that have been purchased earlier but are no longer useful. Identifying such unused and unattached resources and deactivating it on a regular basis brings you one step closer to cost optimization. If needed, you can deploy automated cloud management tools that are largely helpful in providing the analytics needed to optimize the cloud spending and cut costs on an ongoing basis.

• Figure out idle instances

Another key cost optimization strategy is to identify the idle computing instances and consolidate them into fewer instances. An idle computing instance may require a CPU utilization level of 1-5%, but you may be billed by the service provider for 100% for the same instance.

Every enterprise will have such non-production instances that constitute unnecessary storage space and lead to overpaying. Re-evaluating your resource allocations regularly and removing unnecessary storage may help you save money significantly. Resource allocation is not only a matter of CPU and memory but also it is linked to the storage, network, and various other factors.

• Deploy monitoring mechanisms

The key to efficient cost reduction in cloud computing technology lies in proactive monitoring. A comprehensive view of the cloud usage helps enterprises to monitor and minimize unnecessary spending. You can make use of various mechanisms for monitoring computing demand.

For instance, you can use a heatmap to understand the highs and lows in computing visually. This heat map indicates the start and stop times which in turn lead to reduced costs. You can also deploy automated tools that help organizations to schedule instances to start and stop. By following a heatmap, you can understand whether it is safe to shut down servers on holidays or weekends.

#cloud computing services #all #hybrid cloud #cloud #multi-cloud strategy #cloud spend #multi-cloud spending #multi cloud adoption #why multi cloud #multi cloud trends #multi cloud companies #multi cloud research #multi cloud market

Docker Explained: Docker Architecture | Docker Registries

Following the second video about Docker basics, in this video, I explain Docker architecture and explain the different building blocks of the docker engine; docker client, API, Docker Daemon. I also explain what a docker registry is and I finish the video with a demo explaining and illustrating how to use Docker hub

In this video lesson you will learn:

• What is Docker Host
• What is Docker Engine
• Learn about Docker Architecture
• Learn about Docker client and Docker Daemon
• Docker Hub and Registries
• Simple demo to understand using images from registries

#docker #docker hub #docker host #docker engine #docker architecture #api

Top 24 Docker Commands Explained with Examples

In my previous blog post, I have explained in detail how you can Install Docker and Docker-compose on Ubuntu

In this guide, I have explained the Top 24 Docker Commands with examples.

Make sure you have sudo or root privileges to the system.

Docker Commands

1. The command to check the version of Docker installed.
2. To look/search for available docker images from the Docker registry.
3. To pull docker images from the Docker registry.
4. Listing all the docker images
5. Creating / Running docker container from Docker image.
6. To list the actively running docker containers.
7. To list all the docker containers
8. To stop a Container
9. To start a Container
10. To restart a Docker container
11. To login to running Docker container
12. To delete the stopped Docker containers
13. To delete Docker images from the Local system
14. To check logs of a running Docker container
15. Killing docker containers
16. Log in to Docker Hub registry (hub.docker.com)
17. Removing docker hub registry login from the system.
18. Check active resource usage by each containers
19. Rename a Docker container
20. To display system wide information of Docker
21. Inspecting a Docker container
22. Building docker images from Docker file
23. Creating new docker images from a Container
24. Pushing Docker images from Local to Docker registry.

#docker #docker-command #containers #docker-compose #docker-image

Authentication in Node.js - #3 Docker Compose for Development

When it comes to provisioning a local dev environment, you have at least 4 choices. One, you can offload all the heavy lifting to a 3rd-party service. For example, you could use Atlas or mLab for MongoDB, and Redis Labs for Redis. Just copy-paste the connection string, and you’re ready to go. Otherwise, you could also install mongodb-org and redis-server locally on your machine. This is the most intuitive, yet also most intrusive approach as it directly uses your OS to run both processes.

Another option is to install MongoDB and Redis in a VM such as Vagrant, which would eat up substantial resources to run a full-blown Linux OS alongside your host OS. This is probably an overkill when used for development. Lastly, you can provision both databases with Docker and (optionally) Docker Compose. We’ll go with the last option in this tutorial.

First, make sure to install docker and docker-compose on your machine. If you’re new to Docker, it will take some time to get used to, but once you’ve picked on a few simple commands, you can easily spin up light-weight containers for your everyday development. Docker Compose is useful when you need to manage multiple containers under a stack. Just keep in mind that it only works on a single host, and as such is only suited for local development. Don’t get too hung up on it, as you’ll probably use Kubernetes or Swarm in production anyway.

Sadly, MongoDB image doesn’t create an admin user for the initial database, although it’s a open issue on GitHub. To do so, you can map a shell script to the MongoDB entrypoint directory. This could be a JS file as well, except then you won’t have access to environment variables. The shell script needs to authenticate with MongoDB, create an admin user, and grant them write permissions on the initial database.

One issue that you will run into on Linux (either locally during development or in production after deployment) is directory ownership of the data volume. When you map the data directory from a MongoDB container to a local file-system directory, its ownership changes recursively to an elevated user, such as root. You can find this problem described in these GitHub issues.

To fix this on Linux, before running any docker-compose command (not only up, but also stop, down, etc.), you need to (1) explicitly export UID in the current shell, and (2) make the volume directory (with -p if it already exists). This way data directory is owned by the currently logged-in user (i.e. you) and not an elevated user (i.e. root). Otherwise, its ownership will silently change to root, and you may run into critical errors when re-booting the container stack.

#node.js #docker #linux #docker compose