8.9 KiB
aquatic
Blazingly fast, multi-threaded BitTorrent tracker written in Rust, consisting of sub-implementations for different protocols:
| Name | Protocol | OS requirements |
|---|---|---|
| aquatic_udp | BitTorrent over UDP | Cross-platform with mio (default) / Linux 5.8+ with glommio |
| aquatic_http | BitTorrent over HTTP with TLS (rustls) | Linux 5.8+ |
| aquatic_ws | WebTorrent with TLS (rustls) | Linux 5.8+ |
Usage
Prerequisites
- Install Rust with rustup (stable is recommended)
- Install cmake with your package manager (e.g.,
apt-get install cmake) - Unless you're planning to only run aquatic_udp and only the cross-platform,
mio based implementation, make sure locked memory limits are sufficient.
You can do this by adding the following lines to
/etc/security/limits.conf, and then logging out and back in:
* hard memlock 512
* soft memlock 512
- Clone this git repository and enter it
Compiling
Compile the implementations that you are interested in:
cargo build --release -p aquatic_udp
cargo build --release -p aquatic_udp --features "with-glommio" --no-default-features
cargo build --release -p aquatic_http
cargo build --release -p aquatic_ws
Running
Begin by generating configuration files. They differ between protocols.
./target/release/aquatic_udp -p > "aquatic-udp-config.toml"
./target/release/aquatic_http -p > "aquatic-http-config.toml"
./target/release/aquatic_ws -p > "aquatic-ws-config.toml"
Make adjustments to the files. The values you will most likely want to adjust
are socket_workers (number of threads reading from and writing to sockets)
and address under the network section (listening address). This goes for
all three protocols.
aquatic_http requires configuring a TLS certificate file and a private key file
to run. More information is available futher down in this document.
Once done, run the tracker:
./target/release/aquatic_udp -c "aquatic-udp-config.toml"
./target/release/aquatic_http -c "aquatic-http-config.toml"
./target/release/aquatic_ws -c "aquatic-ws-config.toml"
More documentation of configuration file values might be available under
src/lib/config.rs in crates aquatic_udp, aquatic_http, aquatic_ws.
General settings
Access control by info hash is supported for all protocols. The relevant part of configuration is:
[access_list]
mode = 'off' # Change to 'black' (blacklist) or 'white' (whitelist)
path = '' # Path to text file with newline-delimited hex-encoded info hashes
Details on implementations
aquatic_udp: UDP BitTorrent tracker
Aims to implements the UDP BitTorrent protocol, except that it:
- Doesn't care about IP addresses sent in announce requests. The packet source IP is always used.
- Doesn't track of the number of torrent downloads (0 is always sent).
Supports IPv4 and IPv6 (BitTorrent UDP protocol doesn't support IPv6 very well, however.)
For optimal performance, enable setting of core affinities in configuration.
Benchmarks
Server responses per second, best result in bold:
| workers | aquatic | opentracker |
|---|---|---|
| 1 | n/a | 232k |
| 2 | 309k | 293k |
| 3 | 597k | 397k |
| 4 | 603k | 481k |
| 6 | 757k | 587k |
| 8 | 850k | 431k |
| 10 | 826k | 165k |
| 16 | 785k | 139k |
Please refer to documents/aquatic-udp-load-test-2021-08-19.pdf for more details.
Alternative implementation using io_uring
There is an alternative implementation that utilizes io_uring by running on glommio. It only runs on Linux and requires a recent kernel (version 5.8 or later). In some cases, it performs even better than the cross-platform implementation.
aquatic_http: HTTP BitTorrent tracker
Aims for compatibility with the HTTP BitTorrent protocol, with some exceptions:
- Only runs over TLS
- Doesn't track of the number of torrent downloads (0 is always sent)
- Doesn't allow full scrapes, i.e. of all registered info hashes
aquatic_http has not been tested as much as aquatic_udp but likely works
fine.
TLS
A TLS certificate file (DER-encoded X.509) and a corresponding private key file (DER-encoded ASN.1 in either PKCS#8 or PKCS#1 format) are required. Set their paths in the configuration file, e.g.:
[network]
address = '0.0.0.0:3000'
tls_certificate_path = './cert.crt'
tls_private_key_path = './key.pk8'
aquatic_ws: WebTorrent tracker
Aims for compatibility with WebTorrent clients, with some exceptions:
- Only runs over TLS (wss protocol)
- Doesn't track of the number of torrent downloads (0 is always sent).
- Doesn't allow full scrapes, i.e. of all registered info hashes
TLS
Please see aquatic_http TLS section above.
Benchmarks
The following benchmark is not very realistic, as it simulates a small number of clients, each sending a large number of requests. Nonetheless, I think that it gives a useful indication of relative performance.
Server responses per second, best result in bold:
| workers | aquatic | wt-tracker | bittorrent-tracker |
|---|---|---|---|
| 1 | n/a | 117k | 45k |
| 2 | 225k | n/a | n/a |
| 4 | 627k | n/a | n/a |
| 6 | 831k* | n/a | n/a |
| 8 | 1209k* | n/a | n/a |
| 10 | 1455k* | n/a | n/a |
| 12 | 1650k* | n/a | n/a |
| 14 | 1804k* | n/a | n/a |
| 16 | 1789k* | n/a | n/a |
* Using a VPS with 32 vCPUs. The other measurements were made using a 16 vCPU VPS.
Please refer to documents/aquatic-ws-load-test-2021-08-18.pdf for more details.
Note: these benchmarks were made with the previous mio-based implementation.
Load testing
There are load test binaries for all protocols. They use a CLI structure
similar to aquatic and support generation and loading of configuration files.
To run, first start the tracker that you want to test. Then run the corresponding load test binary:
./scripts/run-load-test-udp.sh
./scripts/run-load-test-http.sh
./scripts/run-load-test-ws.sh
To fairly compare HTTP performance to opentracker, set keepalive to false in
aquatic_http settings.
Architectural overview
One or more socket workers open sockets, read and parse requests from peers and send them through channels to request workers. The request workers go through the requests, update shared internal tracker state as appropriate and generate responses that are sent back to the socket workers. The responses are then serialized and sent back to the peers.
This design means little waiting for locks on internal state occurs, while network work can be efficiently distributed over multiple threads, making use of SO_REUSEPORT setting.
Copyright and license
Copyright (c) 2020-2021 Joakim Frostegård
Distributed under Apache 2.0 license (details in LICENSE file.)
Trivia
The tracker is called aquatic because it thrives under a torrent of bits ;-)