Container-based architecture, also known as "microservices," is an approach to designing and running applications as a distributed set of components or layers. Such applications are typically run within containers, made popular in the last few years by Docker.

Containers are portable, efficient, reusable, and contain code and any dependencies in a single package. Containerized services typically run a single process, rather than an entire stack within the same environment. This allows developers to replace, scale, or troubleshoot portions of their entire application at a time.

General Availability (GA) of Kubernetes - Research Computing now manages microservice orchestration with Kubernetes, the open-source tool from Google. New deployments are now launched directly within Kuberenetes.

» Read about Kubernetes and user deployments.

Microservices at UVA

Research Computing runs microservices in a clustered orchestration environment that automates the deployment and management of many containers easy and scalable. This cluster has >1000 cores and ~1TB of memory allocated to running containerized services. It also has over 300TB of cluster storage and can attach to project and value storage.

Basic Principles

1 Microservice architecture is a design approach, or a way of building things. Microservices can be considered the opposite of "monolithic" designs.

A few guiding design principles:

1. Separate components and services
2. Availability and resilience
3. Replaceable elements
4. Easily distributable
5. Reusable components
6. Decentralized elements
7. Easy deployment

Here’s a talk given by Martin Fowler explaining the idea:

2 The easiest and most common way to run microservices is inside of containers.

• We teach workshops on containers and how to use them. Browse the course overview for Building Containers for Rivanna at your own pace.
• Docker provides an excellent Getting Started tutorial.
• Users may inject ENV environment variables and encrypted secrets into containers at runtime. This means sensitive information does not need to be written into your container.

Uses for Research

Microservices are typically used in computational research in one of two ways:

1. Standalone microservices or small stacks - Such as interactive or data-driven web applications and APIs, small databases (<100GB), or scheduled task containers. Some examples:
• Simple web container to serve Project files to the research community or as part of a publication.
• Reference APIs can handle requests based either on static reference data or databases.
• Shiny Server presents users with interactive plots to engage with your datasets.
• A scheduled job to retrieve remote datasets, perform initial ETL processing, and stage them for analysis.
2. Microservices in support of HPC jobs - Some workflows in HPC jobs require supplemental services in order to run, such as relational databases, key-value stores, or reference APIs. Some examples:
• Cromwell/WDL pipelines rely on MySQL databases to track job status and state if a portion of your pipeline fails.
• Key-value stores in Redis can track an index of values or a running count that is updated as part of a job.
• A scheduled job to refresh a library of reference data from an external source, such as reference genomes or public datasets.

Browse a list of recent UVA projects employing microservices.

Common Deployments

	Service	Accessibility	Description
	NGINX Web Server	Public	A fast web server that can run Static HTML demo Flask or Django apps demo RESTful APIs demo Expose Project storage demo
	Apache Web Server	Public	An extremely popular web server that can run your static HTML, Flask or Django apps, RESTful APIs, or expose files stored in Project storage.
	Shiny Server	Public	Runs R-based web applications and offers a dynamic, data-driven user interface. See a demo or try using LOLAweb
	MySQL Database	HPC networks	A stable, easy to use relational database. Run MySQL in support of your HPC projects in Rivanna or web containers.
	mongoDB Database	HPC networks	A popular NoSQL database. Use mongo in support of your Rivanna jobs or web containers. Try Mongo
	Redis Database	HPC networks	An extremely fast, durable, key-value database. Use Redis in support of Rivanna jobs or other processes you run. Try Redis
	Recurring Tasks	n/a	Schedule or automate tasks or data staging using the language of your choice (bash, Python, R, C, Ruby).

Service Eligibility & Limitations

Pricing

Container services hosted by UVA Research Computing fall under this pricing structure:

No charges will be incurred for stopped containers or any cluster storage.

Singularity

Want to run your container within an HPC environment? It can be done, using Singularity!

Singularity is a container application targeted to multi-user, high-performance computing systems. It interoperates well with Slurm and with the Lmod modules system. Singularity can be used to create and run its own containers, or it can import Docker containers.

Learn more about Singularity.

Next Steps

Have a containerized application ready for launch? Or want a consultation to discuss your microservice implementation?

Request Access    Request a Consultation