[VOL-2164] Update rw-core to use the Async Kafka API

This commit consists of the following:

1. Process per-device requests in the Core in the order they are
received. If there are lots of requests on a given device then
there will be some latencies introduced due to ordering.  With
recent changes in the model along with keeping the request lock
to a minimal then these latencies are reduced.  Testing did not
show and noticeable latencies.

2) Keep the request lock from the moment a request started
processing to the moment that request is sent to kafka (when
applicable).  Adapter responses are received and processed
asynchronously. Therefore, an adapter can takes all the time it
needs to process a transaction.  The Core still has a context
with timeout (configurable) to cater for cases where the adapter
does not return a response.

3) Adapter requests are processed to completion before sending a
reponse back to the adapter.  Previously, in some cases, a
separate go routine was created to process the request and a
successful response is sent to the adapter.  Now if the request
fails then the adapter will receive an error. The adapter
requests for a given device are therefore processed in the
order they are received.

4) Some changes are made when retrieving a handler to execute
a device state transition.  This was necessary as there was some
transition overlap found.

Update after multiple reviews.

Change-Id: I55a189efec1549a662f2d71e18e6eca9015a3a17
22 files changed
tree: 90686a69e5f9fdb4d0c4f1f48e372eac5988477c
  1. .gitignore
  2. .gitreview
  3. .golangci.yml
  4. BUILD.md
  6. Makefile
  7. README.md
  9. common/
  10. compose/
  11. db/
  12. docker/
  13. go.mod
  14. go.sum
  15. quickstart.md
  16. rw_core/
  17. tests/
  18. 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.