Chat | API Documentation (main branch)
this repository contains an implementation of TurboWish/tokio-console, a diagnostics and debugging tool for asynchronous Rust programs. the diagnostic toolkit consists of multiple components:
-
a wire protocol for streaming diagnostic data from instrumented applications to diagnostic tools. the wire format is defined using gRPC and protocol buffers, for efficient transport on the wire and interoperability between different implementations of data producers and consumers.
the
console-apicrate contains generated code for this wire format for projects using thetonicgRPC implementation. additionally, projects using other gRPC code generators (including those in other languages!) can depend on the protobuf definitions themselves. -
instrumentation for collecting diagnostic data from a process and exposing it over the wire format. the
console-subscribercrate in this repository contains an implementation of the instrumentation-side API as atracing-subscriberLayer, for projects using Tokio andtracing. -
tools for displaying and exploring diagnostic data, implemented as gRPC clients using the console wire protocol. the
tokio-consolecrate implements an an interactive command-line tool that consumes this data, but other implementations, such as graphical or web-based tools, are also possible.
wow! whoa! it's like top(1) for tasks!
viewing details for a single task:
the console is part of a much larger effort to improve debugging tooling for async Rust. a 2019 Google Summer of Code project by Matthias Prechtl (@matprec) implemented an initial prototype, with a focus on interactive log viewing. more recently, both the Tokio team and the async foundations working group have made diagnostics and debugging tools a priority for async Rust in 2021 and beyond. in particular, a series of blog posts by @pnkfelix lay out much of the vision that this project seeks to eventually implement.
furthermore, we're indebted to our antecedents in other programming languages
and environments for inspiration. this includes tools and systems such as
pprof, Unix top(1) and htop(1), XCode's Instruments, and many
others.
to instrument an application using Tokio, add a dependency on the
console-subscriber crate, and add this one-liner to the top of your
main function:
console_subscriber::init();notes:
-
in order to collect task data from Tokio, the
tokio_unstablecfg must be enabled. for example, you could build your project withRUSTFLAGS="--cfg tokio_unstable" cargo buildor add the following to your
.cargo/config.tomlfile:[build] rustflags = ["--cfg", "tokio_unstable"]
For more information on the appropriate location of your
.cargo/config.tomlfile, especially when using workspaces, see the console-subscriber readme. -
the
tokioandruntimetracingtargets must be enabled at theTRACElevel.-
if you're using the
console_subscriber::init()orconsole_subscriber::BuilderAPIs, these targets are enabled automatically. -
if you are manually configuring the
tracingsubscriber using theEnvFilterorTargetsfilters fromtracing-subscriber, add"tokio=trace,runtime=trace"to your filter configuration. -
also, ensure you have not enabled any of the compile time filter features in your
Cargo.toml.
-
to run the console command-line tool, install tokio-console from crates.io
cargo install --locked tokio-consoleand run locally
tokio-consolealternative method: run the tool from a local checkout of this repository
$ cargo run
by default, this will attempt to connect to an instrumented application running
on localhost on port 6669. if the application is running somewhere else, or is
serving the console endpoint on a different port, a target address can be passed
as an argument to the console (either as an <IP>:<PORT> or
<DNS_NAME>:<PORT>). for example:
cargo run -- http://my.great.console.app.local:5555The console command-line tool supports a number of additional flags to configure
its behavior. The help command will print a list of supported command-line
flags and arguments:
$ tokio-console --help
The Tokio console: a debugger for async Rust.
Usage: tokio-console[EXE] [OPTIONS] [TARGET_ADDR] [COMMAND]
Commands:
gen-config
Generate a `console.toml` config file with the default
configuration values, overridden by any provided command-line
arguments
gen-completion
Generate shell completions
help
Print this message or the help of the given subcommand(s)
Arguments:
[TARGET_ADDR]
The address of a console-enabled process to connect to.
This may be an IP address and port, or a DNS name.
On Unix platforms, this may also be a URI with the `file`
scheme that specifies the path to a Unix domain socket, as in
`file://localhost/path/to/socket`.
[default: http://127.0.0.1:6669]
Options:
--log <LOG_FILTER>
Log level filter for the console's internal diagnostics.
Logs are written to a new file at the path given by the
`--log-dir` argument (or its default value), or to the system
journal if `systemd-journald` support is enabled.
If this is set to 'off' or is not set, no logs will be
written.
[default: off]
[env: RUST_LOG=]
-W, --warn <WARNINGS>...
Enable lint warnings.
This is a comma-separated list of warnings to enable.
Each warning is specified by its name, which is one of:
* `self-wakes` -- Warns when a task wakes itself more than a
certain percentage of its total wakeups. Default percentage is
50%.
* `lost-waker` -- Warns when a task is dropped without being
woken.
* `never-yielded` -- Warns when a task has never yielded.
[default: self-wakes lost-waker never-yielded]
[possible values: self-wakes, lost-waker, never-yielded]
-A, --allow <ALLOW_WARNINGS>...
Allow lint warnings.
This is a comma-separated list of warnings to allow.
Each warning is specified by its name, which is one of:
* `self-wakes` -- Warns when a task wakes itself more than a
certain percentage of its total wakeups. Default percentage is
50%.
* `lost-waker` -- Warns when a task is dropped without being
woken.
* `never-yielded` -- Warns when a task has never yielded.
If this is set to `all`, all warnings are allowed.
[possible values: all, self-wakes, lost-waker, never-yielded]
--log-dir <LOG_DIRECTORY>
Path to a directory to write the console's internal logs to.
[default: /tmp/tokio-console/logs]
--lang <LANG>
Overrides the terminal's default language
[env: LANG=en_US.UTF-8]
--ascii-only <ASCII_ONLY>
Explicitly use only ASCII characters
[possible values: true, false]
--no-colors
Disable ANSI colors entirely
--colorterm <truecolor>
Overrides the value of the `COLORTERM` environment variable.
If this is set to `24bit` or `truecolor`, 24-bit RGB color
support will be enabled.
[env: COLORTERM=truecolor]
[possible values: 24bit, truecolor]
--palette <PALETTE>
Explicitly set which color palette to use
[possible values: 8, 16, 256, all, off]
--no-duration-colors <COLOR_DURATIONS>
Disable color-coding for duration units
[possible values: true, false]
--no-terminated-colors <COLOR_TERMINATED>
Disable color-coding for terminated tasks
[possible values: true, false]
--retain-for <RETAIN_FOR>
How long to continue displaying completed tasks and dropped
resources after they have been closed.
This accepts either a duration, parsed as a combination of
time spans (such as `5days 2min 2s`), or `none` to disable
removing completed tasks and dropped resources.
Each time span is an integer number followed by a suffix.
Supported suffixes are:
* `nsec`, `ns` -- nanoseconds
* `usec`, `us` -- microseconds
* `msec`, `ms` -- milliseconds
* `seconds`, `second`, `sec`, `s`
* `minutes`, `minute`, `min`, `m`
* `hours`, `hour`, `hr`, `h`
* `days`, `day`, `d`
* `weeks`, `week`, `w`
* `months`, `month`, `M` -- defined as 30.44 days
* `years`, `year`, `y` -- defined as 365.25 days
[default: 6s]
-h, --help
Print help (see a summary with '-h')
-V, --version
Print version
the console-subscriber/examples directory contains some potentially useful
tools:
app.rs: a very simple example program that spawns a bunch of tasks in a loop foreverdump.rs: a simple CLI program that dumps the data stream from aTasksserver
Examples can be executed with:
cargo run --example $name