readme: add why & move architecture sections

This commit is contained in:
Jimmy Zelinskie 2016-09-17 18:39:01 -04:00
parent 1304ceb65b
commit 191304890c

View file

@ -26,49 +26,17 @@ Differentiating features include:
[YAML]: http://yaml.org
[Prometheus]: http://prometheus.io
## Architecture
## Why Chihaya?
### Diagram
Chihaya is built for developers looking to integrate BitTorrent into a preexisting production environment.
Chihaya's pluggable architecture and middleware framework offers a simple and flexible integration point that abstracts the BitTorrent tracker protocols.
The most common use case for Chihaya is integration with the deployment of cloud software.
```
+----------------------+
| BitTorrent Client |<--------------+
+----------------------+ |
| |
| |
| |
-------------v--------------------------+-------------------+-------------------------+
|+----------------------+ +----------------------+frontend| chihaya|
|| Parser | | Writer | | |
|+----------------------+ +----------------------+ | |
| | ^ | |
-------------+--------------------------+-------------------+ |
+------------v--------------------------+-------------------+ |
|+----------------------+ +----------------------+ logic| |
|| PreHook Middleware |-->| Response Generator |<-------|-------------+ |
|+----------------------+ +----------------------+ | | |
| | | |
|+----------------------+ | +----------------------+|
|| PostHook Middleware |-----------------------------------|>| Storage ||
|+----------------------+ | +----------------------+|
| | |
+-----------------------------------------------------------+-------------------------+
```
[OpenBittorrent]: https://openbittorrent.com
### Description
### Production Use
BitTorrent clients send Announce and Scrape requests to a _Frontend_.
Frontends parse requests and write responses for the particular protocol they implement.
The _TrackerLogic_ interface to is used to generate responses for their requests and optionally perform a task after responding to a client.
A configurable chain of _PreHook_ and _PostHook_ middleware is used to construct an instance of TrackerLogic.
PreHooks are middleware that are executed before the response has been written.
After all PreHooks have executed, any missing response fields that are required are filled by reading out of the configured implementation of the _Storage_ interface.
PostHooks are asynchronous tasks that occur after a response has been delivered to the client.
Request data is written to the storage asynchronously in one of these PostHooks.
## Production Use
### Facebook
#### Facebook
[Facebook] uses BitTorrent to deploy new versions of their software.
In order to optimize the flow of traffic within their datacenters, Chihaya is configured to prefer peers within the same subnet.
@ -76,7 +44,7 @@ Because Facebook organizes their network such that server racks are allocated IP
[Facebook]: https://facebook.com
### CoreOS
#### CoreOS
[Quay] is a container registry that offers the ability to download containers via BitTorrent in order to speed up large or geographically distant deployments.
Announce URLs from Quay's torrent files contain a [JWT] in order to allow Chihaya to verify that an infohash was approved by the registry.
@ -112,6 +80,42 @@ For more information read [CONTRIBUTING.md].
[freenode IRC]: http://webchat.freenode.net/?channels=chihaya
[CONTRIBUTING.md]: https://github.com/chihaya/chihaya/blob/master/CONTRIBUTING.md
### Architecture
```
+----------------------+
| BitTorrent Client |<--------------+
+----------------------+ |
| |
| |
| |
+------------v--------------------------+-------------------+-------------------------+
|+----------------------+ +----------------------+frontend| chihaya|
|| Parser | | Writer | | |
|+----------------------+ +----------------------+ | |
| | ^ | |
+------------+--------------------------+-------------------+ |
+------------v--------------------------+-------------------+ |
|+----------------------+ +----------------------+ logic| |
|| PreHook Middleware |-->| Response Generator |<-------|-------------+ |
|+----------------------+ +----------------------+ | | |
| | | |
|+----------------------+ | +----------------------+|
|| PostHook Middleware |-----------------------------------|>| Storage ||
|+----------------------+ | +----------------------+|
| | |
+-----------------------------------------------------------+-------------------------+
```
BitTorrent clients send Announce and Scrape requests to a _Frontend_.
Frontends parse requests and write responses for the particular protocol they implement.
The _TrackerLogic_ interface to is used to generate responses for their requests and optionally perform a task after responding to a client.
A configurable chain of _PreHook_ and _PostHook_ middleware is used to construct an instance of TrackerLogic.
PreHooks are middleware that are executed before the response has been written.
After all PreHooks have executed, any missing response fields that are required are filled by reading out of the configured implementation of the _Storage_ interface.
PostHooks are asynchronous tasks that occur after a response has been delivered to the client.
Request data is written to the storage asynchronously in one of these PostHooks.
## Related projects
- [BitTorrent.org](https://github.com/bittorrent/bittorrent.org): a static website containing the BitTorrent spec and all BEPs