statsviz

README

Statsviz

Instant live visualization of your Go application runtime statistics (GC, MemStats, etc.).

• Import import "github.com/arl/statsviz"
• Register statsviz HTTP handlers
• Start your program
• Open your browser at http://host:port/debug/statsviz
• Enjoy...

Usage

go get -u github.com/arl/statsviz

Either Register statsviz HTTP handlers with the http.ServeMux you're using (preferred method):

mux := http.NewServeMux()
statsviz.Register(mux)

Or register them with the http.DefaultServeMux:

statsviz.RegisterDefault()

If your application is not already running an HTTP server, you need to start one. Add "net/http" and "log" to your imports and the following code to your main function:

go func() {
    log.Println(http.ListenAndServe("localhost:6060", nil))
}()

By default the handled path is /debug/statsviz/.

Then open your browser at http://localhost:6060/debug/statsviz/

Examples

Using http.DefaultServeMux:

• _example/default.go

Using your own http.ServeMux:

• _example/mux.go

Using https`:

• _example/https.go

With gorilla/mux Router:

• _example/gorilla/mux.go

Plots

On the plots where it matters, garbage collections are shown as vertical lines.

Heap

MSpans / MCaches

Size classes heatmap

Objects

Goroutines

GC/CPU fraction

Contributing

Pull-requests are welcome! More details in CONTRIBUTING.md

Roadmap

• add stop-the-world duration heatmap
• increase data retention
• light/dark mode selector
• plot image export

Changelog

See CHANGELOG.md.

License

• MIT License

Documentation

Overview

Package statsviz serves via its HTTP server an HTML page displaying live visualization of the application runtime statistics.

Either Register statsviz HTTP handlers with the http.ServeMux you're using (preferred method):

mux := http.NewServeMux()
statsviz.Register(mux)

Or register them with the http.DefaultServeMux:

statsviz.RegisterDefault()

If your application is not already running an HTTP server, you need to start one. Add "net/http" and "log" to your imports and the following code to your main function:

go func() {
	log.Println(http.ListenAndServe("localhost:6060", nil))
}()

Index

• Variables
• func IndexAtRoot(root string) http.Handler
• func Register(mux *http.ServeMux, opts ...OptionFunc) error
• func RegisterDefault(opts ...OptionFunc)
• func Ws(w http.ResponseWriter, r *http.Request)
• type OptionFunc
  • func Root(root string) OptionFunc
  • func SendFrequency(freq time.Duration) OptionFunc

Variables

var Index = IndexAtRoot(defaultRoot)

Index responds to a request for /debug/statsviz with the statsviz HTML page which shows a live visualization of the statistics sent by the application over the websocket handler Ws.

Functions

func IndexAtRoot

func IndexAtRoot(root string) http.Handler

IndexAtRoot returns an index statsviz handler rooted at root. It's useful if you desire your server to responds with the statsviz HTML page at a path that is different than /debug/statsviz.

func Register

func Register(mux *http.ServeMux, opts ...OptionFunc) error

Register registers statsviz HTTP handlers on the provided mux.

func RegisterDefault

func RegisterDefault(opts ...OptionFunc)

RegisterDefault registers statsviz HTTP handlers on the default serve mux.

Note this is not advised on a production server, unless it only serves on localhost.

func Ws

func Ws(w http.ResponseWriter, r *http.Request)

Ws upgrades the HTTP server connection to the WebSocket protocol and sends application statistics every second.

If the upgrade fails, an HTTP error response is sent to the client.

Types

type OptionFunc

type OptionFunc func(s *server) error

An OptionFunc is a server configuration option.

func Root

func Root(root string) OptionFunc

Root sets the root of statsviz handlers.

func SendFrequency

func SendFrequency(freq time.Duration) OptionFunc

SendFrequency defines the frequency at which statistics are sent from the application to the HTML page.