Knapsack Pro

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

Semaphore CI

https://semaphoreci.com

Circle CI

https://circleci.com
Unique feature

Autoscaling made easy / Great CLI

Premium Support

Type of product

SaaS

SaaS, Self-hosted / On Premise

Offers a free plan

Yes

1,300 service minutes every month. Plans to release a free tier for open source projects.

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

Semaphore doesn't have traditional pricing tiers, instead it lists the types of machines you can use and their pricing per second of service. They plan to release an annual plan at some point.

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

N/A

Not clear if they offer any real SLA on support.

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

Allows defining a custom build matrix such that your build can be parallelized accross several different environments.

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

N/A

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

Yes

Allows running builds inside docker containers

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

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

Yes

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

No

Yes

Hosted plans / SaaS

Yes

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

Allows defining complex build workflows with ease

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.

N/A

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?

N/A

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

Provides rich documentation on integrating Semaphore CI in Ruby projects. Also provides sudo access if you need to install system dependencies or C extensions.

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

Provides rich documentation on integrating Semaphore CI in Javascript projects

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

Integration with GitHub and Slack. They allow building iOS projects via their macOS Mojave VM image.

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

No

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

Yes

N/A

Additional notes

List of features is based on Semaphore 2.0

How to run parallel tests on Semaphore CI 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.

Do you know

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Get faster feedback from Semaphore CI and Circle CI server

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Knapsack Pro terminal

Running Rails tests in parallel on Semaphore CI 2.0 with dynamic test files split

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

How to split E2E tests on multiple CI nodes using Cypress.io test runner

Jest JavaScript Testing and CI parallelisation how to do it?

Semaphore CI parallelism integration

Circle CI parallelism integration

Introduction to CI parallelisation with Knapsack Pro

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

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

minutes
$

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

Features that make your tests perform better

Discover all features or see
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 east 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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