Knapsack Pro

Jenkins vs Circle CI comparison of Continuous Integration servers
What are the differences between Jenkins and Circle CI?

Jenkins

https://jenkins.io

Circle CI

https://circleci.com
Unique feature

Plugins

Premium Support

Type of product

Self-hosted / On Premise

SaaS, Self-hosted / On Premise

Offers a free plan

Yes

Free, open source software

Yes

Provides a free plan for it's SaaS solution, for up to 1000 build minutes per month, 1 container and 1 concurrent job. On top of this, it has a special Free Tier for open source projects, which extend the number of containers and concurrent jobs available.
Predictable pricing

Yes

Jenkins is free software, the only costs are those assigned to running your infrastructure.

Yes

Provides a calculator, based on the number of concurrent jobs and containers, which can be used to determine pricing before purchase. They also give a guideline based on the number of developers you employ (2-3 containers per full-time developer)
Support / SLA

No (partial)

No official support available, or SLAs. However, Jenkins' popularity ensures you'll find support in various places (official Jenkins forum, IRC, StackOverflow etc.)

Yes

While it's community is not quite as vibrant as it is for Jenkins, CircleCI even offers support premium support for companies who cannot afford any downtime in their CI/CD pipelines (https://circleci.com/support/premium-support/). For the regular plans, all plans except the free tier offer official email support. The free tier only includes community support (Discuss, StackOverflow, etc.)
Paralellism
Every CI servers tends to address this differently (parallel, distributed, build matrix). Some of it is just marketing, and some is just nuance. For this table, parallel means that tasks can be run concurrently on the same machine, distributed means that tasks can be scaled horizontally, on multiple machines
How to split tests in parallel in the optimal way with Knapsack Pro

Yes (partial)

Jenkins allows builds to be run in parallel, but all builds share the same environment and there can be issues arising from shared resources such as the filesystem.

Yes

CircleCI can run builds in parallel, each build in a completely isolated environment by using containers.
Distributed builds
distributed means that tasks can be scaled horizontally, on multiple machines
How to split tests in parallel in the optimal way with Knapsack Pro

Yes (partial)

Jenkins has a concept of master server and agents, for distributing builds, but setting that up requires quite a bit of manual work from a sysadmin, compared to other options.

Yes

The SaaS version distributes builds by default, while the self-hosted version has all the tools built-in for managing the cluster of builder machines.
Containers support / Build environment

No (partial)

By default, Jenkins runs all builds in the same environment as the build server itself, which can lead to numerous issues and is generally not a good practice. Some plugins address this issue, but they need to be manually installed.

Yes

CircleCI runs every build in a container, or VM, ensuring an isolated, local scope for each build. The environment is also reset with each build, which can highlight hard-to-track issues related to assumptions about the environment that the project is deployed to.
Analytics / Status overview
Analytics and overview referrs to the ability to, at a glance, see what's breaking (be it a certain task, or the build for a specific project)

Yes

Available via the Blue Ocean project (part of Jenkins): https://jenkins.io/doc/book/blueocean/dashboard/#dashboard

Yes

Available by default in Circle CI: https://circleci.com/docs/2.0/status/#section=jobs. Aditionally, the Insights Dashboard provides a very useful overview on build times, error rates and status for your projects: https://circleci.com/docs/2.0/insights/#section=jobs
Management support
How easy is it to manage users / projects / assign roles and permissions and so on

No

In practice, for Jenkins it usually means that there's someone solely in charge of the Jenkins instance (configuration, management). Collaboration features built into other similar products are lacking, as are governance features (no easy way to tell from Jenkins alone _who_ is responsabile for a broken build, for example), even if your Version Control Server of choice can give that information (via `git blame` for example).

No (partial)

Using the Cloud plan for Circle CI requires no dedicated person for maintanence / management of the service. The CircleCI Server option (self-hosted) is also hassle free, as the process of installing and managing CircleCI and it's dependencies is automated. Developers are also given SSH acces to the builds (not the whole environment), while sys-admins can work on the host machine without worry about affecting the builds (which are containerized).
Self-hosted option

Yes

Jenkins is Open Source Software, and self-hosting is the only way to use it.

Yes

Hosted plans / SaaS

No

Only available for self-hosting.

Yes

Build pipelines
A continuous delivery pipeline is a description of the process that the software goes through from a new code commit, through testing and other statical analysis steps all the way to the end-users of the product.

Yes

Offers extensive support for custom pipelines, either through the Jenkins Pipeline DSL, written in a Jenkinsfile, either through the Web UI. Also, their Blue Ocean project is a great tool for building pipelines: https://jenkins.io/projects/blueocean/

Yes

Pipelines in CircleCI are defined declaratively using an Yaml config file. CircleCI has special provisions for storing secrets in these files.
Reports
Reports are about the abilty to see specific reports (like code coverage or custom ones), but not necesarily tied in into a larger dashboard.

Yes

Has ready-made integrations for standard reports such as JUnit test results.

Yes

Reports are available
Ecosystem
Besides the official documentation and software, is there a large community using this product? Are there any community-driven tools / plugins that you can use?

> 1000 community plugins

Thanks to it's popularity, there's a large selection of available plugins for Jenkins. They can all be easily browsed over at https://plugins.jenkins.io/. The downside is that almost anything you want to do in Jenkins requires installing a plugin, even core functionality such as parsing output or checking out source code.

Yes, partially

While CircleCI doesn't natively support plugins, it's core features address all of the core functionality that a CI/CD service needs. For integrating with other platforms or tools, there are integrations such as https://slack.com/apps/A0F7VRE7N-circleci. Certain jobs are available as CircleCI Orbs: https://circleci.com/orbs/
Specific language support: Ruby
Some CI servers have built-in support for parsing RSpec or Istanbul output for example and we mention those. Some others make it even easier by detecting Gemfiles or package.json and automate parts of the process for the developer.

Yes (Partial)

RSpec and Cucumber test suites can be integrated into Jenkins thanks to the large pool of available plugins and Ruby gems. Jenkins only understands the JUnit format natively.

Yes

For collecting test metadata and coverage, there is built-in support for Ruby (specifically, Cucumber and RSpec). Setting this up takes very little time and is well-documented on CircleCI's docs.
Specific language support: JavaScript

Yes (Partial)

Jest, AVA and other test suites can be integrated into Jenkins thanks to the large pool of available plugins and NPM packages. Jenkins only understands the JUnit format natively.

Yes

For collecting test metadata and coverage, there is built-in support for Javascript. For code coverage, CircleCI understands Istanbul output (Jest also uses Istanbul for the code coverage reports), while for test metadata, the JUnit output format is natively supported.
Integrations
1st party support for common tools (like Slack notifications, various VCS platforms, etc)

Yes

Allows integrations with other tools (ie: Slack, GitHub) or communication protocols (ie: email) via it's rich plugin suite

Yes

Available as CircleCI Orbs: https://circleci.com/orbs/
API
Custom integreation is available, via an API or otherwise, it's mentioned separately as it allows further customization than any of the Ecosystem/Integration options

Yes

For use-cases that the +1k plugins don't cover, the Jenkins Remote API is yet another way to integrate Jenkins into your favorite tools or internal products.

Yes

REST API documentation available at https://circleci.com/docs/api/#api-overview. Creating Orbs is also documented at https://circleci.com/docs/2.0/orb-author/#introduction
Auditing

No

Jenkins instances are really managed by a sole user with administrative privileges. This can lead to various issues when it comes to audit trails / accountability.

N/A

Additional notes

How to run parallel tests on Jenkins and Circle CI
to execute 1-hour test suite in 2 minutes?

Without Knapsack Pro

you have to wait 20 minutes for slow tests running too long on the red node

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Run fast parallel CI build with Knapsack Pro

CI build completes work in only 10 minutes because Knapsack Pro ensures all parallel nodes finish work at a similar time

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You can even run 20 parallel nodes to complete your CI build in 2 minutes

How it works

Step 1

Install Knapsack Pro client in your project


Step 2

Update your CI server config file to run tests in parallel with Knapsack Pro


Step 3

Run a CI build with parallel tests using Knapsack Pro

Diagram that shows files distributed to 3 parallel CI nodes


Knapsack Pro in Queue Mode splits tests in a dynamic way across parallel CI nodes to ensure each CI node finishes work at a similar time. Thanks to that, your CI build time is as fast as possible. It works with many supported CI servers.

How to install it

Programming Language Supported test runners Installation guide Knapsack Pro Library
README / Source
Ruby RSpec, Cucumber, Minitest, test-unit, Spinach, Turnip Install knapsack_pro gem
JavaScript Cypress.io Install @knapsack-pro/cypress
JavaScript Jest Install @knapsack-pro/jest
JavaScript / TypeScript Any test runner in JavaScript How to build native integration with Knapsack Pro API to run tests in parallel for any test runner @knapsack-pro/core
Any programming language Any test runner How to build a custom Knapsack Pro API client from scratch in any programming language -

Do you use other programming language or test runner? Let us know.

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Get faster feedback from Jenkins and Circle CI server

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Knapsack Pro terminal

Continuous delivery pipelines in Jenkins and CI parallelisation

How to get faster Circle CI builds with dynamic test suite split instead of deterministic split

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Jest JavaScript Testing and CI parallelisation how to do it?

Jenkins parallelism integration

Circle CI parallelism integration

Introduction to CI parallelisation with Knapsack Pro

Run tests in parallel on Jenkins and Circle CI in the optimal way and avoid bottleneck parallel jobs.

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How much can you save with faster tests
on Jenkins and Circle CI?

minutes
$

Monthly you can save hours
and up to $
on faster development cycle.

Features that make your tests perform better

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how to use Knapsack Pro with your CI

Trusted solution

Join the teams optimizing their tests with Knapsack Pro.

We've been really enjoying Knapsack Pro, it's been saving us a ton of time.

Devin Brown Software Engineer at Pivotal

This is a fantastic product, it's been a total game-changer for us.

Geoff Harcourt CTO at CommonLit

We are using CircleCI and we noticed that builds were being limited by the slowest parallelized container. Knapsack Pro was really easy to setup and we saw huge improvements right away. Thank you for making this tool!

Martin Sieniawski Software Engineer at Collage

Knapsack Pro has helped us build an insanely fast and scalable build pipeline with almost no setup or maintenance.

Tim Lucas Co-founder of buildkite.com

Knapsack Pro saves us hours of engineer waiting time every week, and is the best solution for keeping our tests load balanced that we've used to date.

Michael Amygdalidis Senior Software Engineer at Popular Pays

I've been playing with Queue Mode. Love it! Wow, I love how fast it goes.

Michael Menne CTO at humanagency.org

I just logged into my account expecting it to say that I needed to add a credit card and was so surprised and delighted to see the trial doesn't count usage by calendar days but by testing days! This is incredible! I love it!!!

I just wanted to say that I really appreciate that small but very huge feature. Thank you for being so thoughtful :)

Shannon Baffoni Senior Software Engineer
at Blue Bottle Coffee

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