A Rust HTTP server for Python applications.
The main reasons behind Granian design are:
- Have a single, correct HTTP implementation, supporting versions 1, 2 (and eventually 3)
- Provide a single package for several platforms
- Avoid the usual Gunicorn + uvicorn + http-tools dependency composition on unix systems
- Provide stable performance when compared to existing alternatives
- Supports ASGI/3, RSGI and WSGI interface applications
- Implements HTTP/1 and HTTP/2 protocols
- Supports HTTPS
- Supports Websockets
You can install Granian using pip:
$ pip install granian
Create an ASGI application in your main.py:
async def app(scope, receive, send):
assert scope['type'] == 'http'
await send({
'type': 'http.response.start',
'status': 200,
'headers': [
[b'content-type', b'text/plain'],
],
})
await send({
'type': 'http.response.body',
'body': b'Hello, world!',
})and serve it:
$ granian --interface asgi main:app
You can also create an app using the RSGI specification:
async def app(scope, proto):
assert scope.proto == 'http'
proto.response_str(
status=200,
headers=[
('content-type', 'text/plain')
],
body="Hello, world!"
)and serve it using:
$ granian --interface rsgi main:app
You can check all the options provided by Granian with the --help command:
$ granian --help
Usage: granian [OPTIONS] APP
APP Application target to serve. [required]
Options:
--host TEXT Host address to bind to [env var:
GRANIAN_HOST; default: (127.0.0.1)]
--port INTEGER Port to bind to. [env var: GRANIAN_PORT;
default: 8000]
--interface [asgi|asginl|rsgi|wsgi]
Application interface type [env var:
GRANIAN_INTERFACE; default: (rsgi)]
--http [auto|1|2] HTTP version [env var: GRANIAN_HTTP;
default: (auto)]
--ws / --no-ws Enable websockets handling [env var:
GRANIAN_WEBSOCKETS; default: (enabled)]
--workers INTEGER RANGE Number of worker processes [env var:
GRANIAN_WORKERS; default: 1; x>=1]
--threads INTEGER RANGE Number of threads [env var:
GRANIAN_THREADS; default: 1; x>=1]
--blocking-threads INTEGER RANGE
Number of blocking threads [env var:
GRANIAN_BLOCKING_THREADS; default: 1; x>=1]
--threading-mode [runtime|workers]
Threading mode to use [env var:
GRANIAN_THREADING_MODE; default: (workers)]
--loop [auto|asyncio|uvloop] Event loop implementation [env var:
GRANIAN_LOOP; default: (auto)]
--opt / --no-opt Enable loop optimizations [env var:
GRANIAN_LOOP_OPT; default: (disabled)]
--backlog INTEGER RANGE Maximum number of connections to hold in
backlog [env var: GRANIAN_BACKLOG; default:
1024; x>=128]
--http1-buffer-size INTEGER RANGE
Set the maximum buffer size for HTTP/1
connections [env var:
GRANIAN_HTTP1_BUFFER_SIZE; default: 417792;
x>=8192]
--http1-keep-alive / --no-http1-keep-alive
Enables or disables HTTP/1 keep-alive [env
var: GRANIAN_HTTP1_KEEP_ALIVE; default:
(enabled)]
--http1-pipeline-flush / --no-http1-pipeline-flush
Aggregates HTTP/1 flushes to better support
pipelined responses (experimental) [env
var: GRANIAN_HTTP1_PIPELINE_FLUSH; default:
(disabled)]
--http2-adaptive-window / --no-http2-adaptive-window
Sets whether to use an adaptive flow control
for HTTP2 [env var:
GRANIAN_HTTP2_ADAPTIVE_WINDOW; default:
(disabled)]
--http2-initial-connection-window-size INTEGER
Sets the max connection-level flow control
for HTTP2 [env var: GRANIAN_HTTP2_INITIAL_C
ONNECTION_WINDOW_SIZE; default: 1048576]
--http2-initial-stream-window-size INTEGER
Sets the `SETTINGS_INITIAL_WINDOW_SIZE`
option for HTTP2 stream-level flow control
[env var:
GRANIAN_HTTP2_INITIAL_STREAM_WINDOW_SIZE;
default: 1048576]
--http2-keep-alive-interval INTEGER
Sets an interval for HTTP2 Ping frames
should be sent to keep a connection alive
[env var: GRANIAN_HTTP2_KEEP_ALIVE_INTERVAL]
--http2-keep-alive-timeout INTEGER
Sets a timeout for receiving an
acknowledgement of the HTTP2 keep-alive ping
[env var: GRANIAN_HTTP2_KEEP_ALIVE_TIMEOUT;
default: 20]
--http2-max-concurrent-streams INTEGER
Sets the SETTINGS_MAX_CONCURRENT_STREAMS
option for HTTP2 connections [env var:
GRANIAN_HTTP2_MAX_CONCURRENT_STREAMS;
default: 200]
--http2-max-frame-size INTEGER Sets the maximum frame size to use for HTTP2
[env var: GRANIAN_HTTP2_MAX_FRAME_SIZE;
default: 16384]
--http2-max-headers-size INTEGER
Sets the max size of received header frames
[env var: GRANIAN_HTTP2_MAX_HEADERS_SIZE;
default: 16777216]
--http2-max-send-buffer-size INTEGER
Set the maximum write buffer size for each
HTTP/2 stream [env var:
GRANIAN_HTTP2_MAX_SEND_BUFFER_SIZE; default:
409600]
--log / --no-log Enable logging [env var:
GRANIAN_LOG_ENABLED; default: (enabled)]
--log-level [critical|error|warning|warn|info|debug]
Log level [env var: GRANIAN_LOG_LEVEL;
default: (info)]
--log-config FILE Logging configuration file (json) [env var:
GRANIAN_LOG_CONFIG]
--ssl-keyfile FILE SSL key file [env var: GRANIAN_SSL_KEYFILE]
--ssl-certificate FILE SSL certificate file [env var:
GRANIAN_SSL_CERTIFICATE]
--url-path-prefix TEXT URL path prefix the app is mounted on [env
var: GRANIAN_URL_PATH_PREFIX]
--respawn-failed-workers / --no-respawn-failed-workers
Enable workers respawn on unexpected exit
[env var: GRANIAN_RESPAWN_FAILED_WORKERS;
default: (disabled)]
--respawn-interval FLOAT The number of seconds to sleep between
workers respawn [env var:
GRANIAN_RESPAWN_INTERVAL; default: 3.5]
--reload / --no-reload Enable auto reload on application's files
changes (requires granian[reload] extra)
[env var: GRANIAN_RELOAD; default:
(disabled)]
--process-name TEXT Set a custom name for processes (requires
granian[pname] extra) [env var:
GRANIAN_PROCESS_NAME]
--version Show the version and exit.
--help Show this message and exit.Granian offers two different threading paradigms, due to the fact the inner Rust runtime can be multi-threaded – in opposition to what happens in Python event-loop which can only run as a single thread.
Given you specify N threads with the relevant option, in workers threading mode Granian will spawn N single-threaded Rust runtimes, while in runtime threading mode Granian will spawn a single multi-threaded runtime with N threads.
Benchmarks suggests workers mode to be more efficient with a small amount of processes, while runtime mode seems to scale more efficiently where you have a large number of CPUs. Real performance will though depend on specific application code, and thus your mileage might vary.
With the --opt option Granian will use custom task handlers for Python coroutines and awaitables to improve Python code execution. Due to the nature of such handlers some libraries and specific application code relying on asyncio internals might not work.
You might test the effect such optimizations cause over your application and decide whether to enable 'em or leave 'em disabled (as per default).
Granian is currently under active development.
Granian is compatible with Python 3.8 and above versions.
Granian is released under the BSD License.
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