polly

polly - Polymorphic Volume Scheduling

Release 0.1.0 (05/01/2016)

Polly is still considered work in progress. We will have a first release shortly.

Storage scheduling for container schedulers

Polly implements a centralized storage scheduling service that integrates with popular container schedulers of different application platforms for containerized workloads. It is an open source framework that supports use of external storage, with scheduled containerized workloads, at scale. It can be used to centralize the control of creating, mapping, snapshotting and deleting persistent data volumes on a multitude of storage platforms.

Key Features

• Centralized control and distribution of storage resources
• Offer based mechanism for advertising storage to container schedulers
• Framework supporting direct integration to any container scheduler, storage orchestrator, and storage platform

What it does

Container runtime schedulers need to be integrated with every aspect of available hardware resources, including persistent storage. When requesting resources for an application the scheduler gets offers for CPU, RAM and disk.

To be able to offer persistent storage in a scalable way, the application and container scheduler needs awareness of the available resources from the underlying storage infrastructure.

Example workflow

1. An application requires highly available storage with a specific set of policies applied
2. The scheduler receives a request to start the application
3. The scheduler checks with Polly or already has an off from Polly for storage resources
4. Polly requests the volume(s) to be mapped to the container
5. Scheduler issues request to start the container with persistent storage
6. Container runtime orchestrates process of starting container and attaching persistent storage

Framework to support the following platforms

Polly provides an open framework to enable integration to any container, cloud, or storage platform.

Container runtime schedulers:

• Docker Swarm
• Mesos
• Kubernetes
• Cloud Foundry

Cloud platforms:

• AWS EC2 (EBS)
• Google Compute Engine
• OpenStack
• Private Cloud
• Public Cloud (RackSpace, and others)

Planned supported storage platforms:

• EMC ScaleIO
• XtremIO
• VMAX
• Isilon
• Others
• VirtualBox

Installation

The following command will install Polly. If using CentOS, RedHat, Ubuntu, or Debian the necessary service manager is used to bootstrap the process on startup.

curl -sSL https://dl.bintray.com/emccode/polly/install | sh -

libStorage

Polly makes use of the open source storage plugin framework libStorage to enable storage orchestrator tools and container runtimes to make requests of storage. Any storage platform that has a driver implementation for the libStorage framework will work with Polly.