VOL-3121 - Separated out LogicalDevices' low-level flow/meter/group handling into separate packages.

The new implementation hides the compexity of locking, caching, and interacting with the db.
An attempt was made to ensure that locks are held while updates are made, by returning a "handle" object from each flow/group/meter lock() call, and only allowing access through this call.

An attempt was also made to remove proto.Clone-ing.  flows/groups/meters which are returned are NOT cloned, and MUST NOT be modified by users of the flow/group/meter loaders.  In addition, flows/groups/meters which are given to the loaders MUST NOT be modified afterward.

There remain many cases where errors during particular kv updates may cause inconsistent state.  TODOs have been added for many of these cases.  Resolving this may require exposing (through voltha-lib-go) the transaction mechanism from etcd.

There is also the issue that locking a flow/meter/group while another flow/meter/group is held could cause deadlocks.  This can be avoided by acquiring locks in a consistent order.  Something to keep in mind while fixing the previous issue.
Change-Id: I146eb319c3564635fdc461ec17be13e6f3968cf7
19 files changed
tree: 7c78f5b42996f906aa16bd0324906f636f7c5c1a
  1. .gitignore
  2. .gitreview
  3. .golangci.yml
  4. BUILD.md
  6. Makefile
  7. README.md
  9. compose/
  10. db/
  11. docker/
  12. go.mod
  13. go.sum
  14. quickstart.md
  15. rw_core/
  16. tests/
  17. vendor/


What is Voltha?

Voltha aims to provide a layer of abstraction on top of legacy and next generation access network equipment for the purpose of control and management. Its initial focus is on PON (GPON, EPON, NG PON 2), but it aims to go beyond to eventually cover other access technologies (xDSL, Docsis, G.FAST, dedicated Ethernet, fixed wireless).

Key concepts of Voltha:

  • Network as a Switch: It makes a set of connected access network devices to look like a(n abstract) programmable flow device, a L2/L3/L4 switch. Examples:
    • PON as a Switch
    • PON + access backhaul as a Switch
    • xDSL service as a Switch
  • Evolution to virtualization: it can work with a variety of (access) network technologies and devices, including legacy, fully virtualized (in the sense of separation of hardware and software), and in between. Voltha can run on a decice, on general purpose servers in the central office, or in data centers.
  • Unified OAM abstraction: it provides unified, vendor- and technology agnostic handling of device management tasks, such as service lifecycle, device lifecycle (including discovery, upgrade), system monitoring, alarms, troubleshooting, security, etc.
  • Cloud/DevOps bridge to modernization: it does all above while also treating the abstracted network functions as software services manageable much like other software components in the cloud, i.e., containers.

Why Voltha?

Control and management in the access network space is a mess. Each access technology brings its own bag of protocols, and on top of that vendors have their own interpretation/extension of the same standards. Compounding the problem is that these vendor- and technology specific differences ooze way up into the centralized OSS systems of the service provider, creating a lot of inefficiencies.

Ideally, all vendor equipment for the same access technology should provide an identical interface for control and management. Moreover, there shall be much higher synergies across technologies. While we wait for vendors to unite, Voltha provides an increment to that direction, by confining the differences to the locality of access and hiding them from the upper layers of the OSS stack.

How can you work with Voltha?

You can start by reading the published documentation.
Another great way is to check out the BUILD.md file to see how you can build it, run it, test it, etc.

How can you help?

Contributions, small and large, are welcome. Minor contributions and bug fixes are always welcome in form of pull requests. For larger work, the best is to check in with the existing developers to see where help is most needed and to make sure your solution is compatible with the general philosophy of Voltha. Please check out the contributing page on the documentation.