Apache Cotton

Apache Cotton (previously named Mysos) is an Apache Mesos framework for running MySQL instances. It dramatically simplifies the management of a MySQL cluster and is designed to offer:

• Efficient hardware utilization through multi-tenancy (in performance-isolated containers)
• High reliability through preserving the MySQL state during failure and automatic backing up to/restoring from HDFS
• An automated self-service option for bringing up new MySQL clusters
• High availability through automatic MySQL master failover
• An elastic solution that allows users to easily scale up and down a MySQL cluster by changing the number of slave instances

Cotton has been accepted into the Apache Incubator.

Documentation

A user guide is available. Documentation improvements are always welcome, so please send patches our way.

Getting Involved

Please check out the source code from Apache's git repostory:

git clone https://git-wip-us.apache.org/repos/asf/incubator-cotton.git

or if you prefer GitHub, use the GitHub mirror:

git clone https://github.com/apache/incubator-cotton.git

The Cotton community maintains the following project supporting services:

• IRC channel: #cotton on irc.freenode.net
• Reporting issues: JIRA issue tracker.
• Submitting patches: Review board.
• Development Mailing List (Archives)

License

Licensed under the Apache License, Version 2.0: http://www.apache.org/licenses/LICENSE-2.0

Requirements

• Python 2.7
• Mesos Python bindings

Building

Building/Downloading Mesos Python Bindings

Cotton uses Mesos Python bindings which consist of two Python packages. mesos.interface is on PyPI and gets automatically installed but mesos.native is platform dependent. You need to either build the package on your machine (instructions) or download a compiled one for your platform (e.g. Mesosphere hosts the eggs for some Linux platforms).

Since pip doesn't support eggs, you need to convert eggs into wheels using wheel convert, then drop them into the 3rdparty folder. See the README file for more information.

Building Cotton

Cotton mainly consists of two components that are built and deployed separately.

• mysos_scheduler: The scheduler that connects to Mesos master and manages the MySQL clusters.
• mysos_executor: The executor that is launched by Mesos slave (upon mysos_scheduler's request) to carry out MySQL tasks.

One way to package these components and their dependencies into a self-contained executable is to use PEX. This allow Cotton components to be launched quickly and reliably. See End-to-end test using PEX for an example of packaging and deploying the executor using PEX.

Testing

Unit Tests

Make sure tox is installed and just run:

tox

The unit tests don't require the mesos.native package to be available in 3rdparty. Tox also builds the Cotton source package and drops it in .tox/dist.

End-to-end Test on a Local Mesos Cluster and PEX

Build/download the mesos.native package and put it in 3rdparty and then run:

tox -e pex

This test demonstrates how to package a PEX executor and use it to launch a fake MySQL cluster on a local Mesos cluster.

End-to-end Test on a Real Mesos Cluster in a Vagrant VM

The Vagrant test uses the sdist Cotton package in .tox/dist so be sure to run tox first. Then:

vagrant up

# Wait for the VM and Cotton API endpoint to come up (http://192.168.33.17:55001 becomes available).

tox -e vagrant

test.sh verifies that Cotton successfully creates a MySQL cluster and then deletes it.