# README
Mirrorbits
Mirrorbits is a geographical download redirector written in Go for distributing files efficiently across a set of mirrors. It offers a simple and economic way to create a full Content Delivery Network layer using a pure software stack. It is primarily designed for the distribution of large-scale Open-Source projects with a lot of traffic.
Main Features
- Blazing fast, can reach 8K req/s on a single laptop
- Easy to deploy and maintain, everything is packed in a single binary
- Automatic synchronization over rsync or FTP
- Response can be either JSON or HTTP redirect
- Support partial repositories
- Complete checksum / size control
- Realtime monitoring and reports
- Disable misbehaving mirrors without human intervention
- Realtime decision making based on location, AS number and defined rules
- Smart load-balancing over multiple mirrors in the same area to avoid hotspots
- Ability to adjust the weight of each mirror
- Limit access to a country, region or ASN for any mirror
- Realtime statistics per file / mirror / date
- Realtime reconfiguration
- Seamless binary upgrade (aka zero downtime upgrade)
- Full IPv6 support
- more...
Is it production ready?
Almost! Mirrorbits is already running in production at VideoLAN to distribute VLC media player since April 2014. Yet some things might change before the 1.0 release, notably the response of a JSON request and few configuration items. If you intend to deploy Mirrorbits in a production system it is strongly advised to contact the author first!
Quick start
Prerequisites
- Redis 2.8 (or later)
- libgeoip
- a recent geoip database (see contrib/geoip/)
Installation
You can either get a prebuilt version or choose to build it yourself.
Manual build
$ go get github.com/etix/mirrorbits
$ go install -v github.com/etix/mirrorbits
The resulting executable should now be in your $GOPATH/bin directory.
If you plan to use the web UI be sure to copy the templates into your system (usually in /usr/share/mirrorbits).
Configuration
A sample configuration file can be found here.
| Option | description |
|---|---|
| Repository | Path to your own copy of the repository |
| Templates | Path containing the templates |
| OutputMode | auto: based on the Accept header content redirect: do an HTTP redirect to the destination json: return a JSON formatted document (also known as API mode) |
| ListenAddress | Local address and port to bind |
| Gzip | Use gzip compression for the JSON responses |
| RedisAddress | Address and port of the Redis database |
| RedisPassword | Password to access the Redis database |
| LogDir | Path to the directory where to save log files |
| GeoipDatabasePath | Path to the geoip databases |
| ConcurrentSync | Maximum number of server sync (rsync/ftp) do to simultaneously |
| DisallowRedirects | Disable any mirror trying to do an HTTP redirect |
| WeightDistributionRange | Multiplier of the distance to the first mirror to find other possible mirrors in order to distribute the load |
| DisableOnMissingFile | Disable a mirror if an advertised file on rsync/ftp appears to be missing on HTTP |
| Fallbacks | A list of possible mirrors to use as fallback if a request fails or if the database is unreachable. These mirrors are not tracked by mirrorbits. It is assumed they have all the files available in the local repository. |
Running
Mirrorbits is a self-contained application and act, at the same time, as the server and the cli.
To run the server:
mirrorbits -D
Additionnal options can be found with mirrobits -help.
To run the cli:
mirrorbits help
Upgrading
Mirrorbits has a mode called seamless binary upgrade to upgrade the server executable at runtime without service disruption. Once the binary has been replaced on the filesystem just issue the following command in the cli:
mirrorbits upgrade
Considerations
- When configured in redirect mode, Mirrorbits can easily serve client requests directly but it is usually recommended to set it behind a reverse proxy like nginx. In this case take care to pass the IP address of the client within a X-Forwarded-For header:
proxy_set_header X-Forwarded-For $remote_addr;
- It is advised to never cache requests intended for Mirrorbits since each request is supposed to be unique, caching the result might have unexpected consequences.
- Having multiple instances of Mirrorbits sharing the same database is not yet (officially) supported, therefore don't do it in production.
We're social!
The best place to discuss about mirrorbits is to join the #VideoLAN IRC channel on Freenode.
For the latest news, you can follow @mirrorbits on Twitter.
License MIT
Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.