Pprof

Hertz provides the pprof extension to help users perform performance analysis on Hertz projects. The implementation of the pprof extension refers to the implementation of Gin.

Install

go get github.com/hertz-contrib/pprof

Example

package main

import (
	"context"

	"github.com/cloudwego/hertz/pkg/app"
	"github.com/cloudwego/hertz/pkg/app/server"
	"github.com/cloudwego/hertz/pkg/common/utils"
	"github.com/cloudwego/hertz/pkg/protocol/consts"
	"github.com/hertz-contrib/pprof"
)

func main() {
    h := server.Default()

    pprof.Register(h)

    h.GET("/ping", func(c context.Context, ctx *app.RequestContext) {
    ctx.JSON(consts.StatusOK, utils.H{"ping": "pong"})
    })

    h.Spin()
}

Config

PrefixOptions

The default prefix of pprof is debug/pprof, that is, after the user registers and uses pprof extension in the Hertz project, the user can view the sampling information of the current project by visiting localhost:8888/debug/pprof. Additionally, pprof supports user-defined prefixes.

The function signature is as follows:

Register(r *server.Hertz, prefixOptions ...string)

Sample code:

package main

import (
	"context"

	"github.com/cloudwego/hertz/pkg/app"
	"github.com/cloudwego/hertz/pkg/app/server"
	"github.com/cloudwego/hertz/pkg/common/utils"
	"github.com/cloudwego/hertz/pkg/protocol/consts"
	"github.com/hertz-contrib/pprof"
)

func main() {
	h := server.Default()

	// default is "debug/pprof"
	pprof.Register(h, "dev/pprof")

	h.GET("/ping", func(c context.Context, ctx *app.RequestContext) {
		ctx.JSON(consts.StatusOK, utils.H{"ping": "pong"})
	})

	h.Spin()
}

RouteRegister

pprof can be registered not only on the Hertz object, but also on the router group (RouterGroup).

The function signature is as follows:

RouteRegister(rg *route.RouterGroup, prefixOptions ...string)

The pprof prefix registered in this way is the result of splicing the prefix of the routing group and the custom prefix.

  • If the user does not specify a prefix, the prefix of the registered pprof is the result of concatenating the prefix of the routing group and the default prefix /debug/pprof, that is, /xxx/debug/pprof (xxx is the prefix of the routing group);
  • If the user specifies a prefix, the prefix of the registered pprof is the result of concatenating the prefix of the routing group and the custom prefix. For example, in the following example, the registered pprof prefix is /admin/pprof.

Sample code:

package main

import (
	"context"

	"github.com/cloudwego/hertz/pkg/app"
	"github.com/cloudwego/hertz/pkg/app/server"
	"github.com/cloudwego/hertz/pkg/common/utils"
	"github.com/cloudwego/hertz/pkg/protocol/consts"
	"github.com/hertz-contrib/pprof"
)

func main() {
	h := server.Default()

	pprof.Register(h)

	adminGroup := h.Group("/admin")

	adminGroup.GET("/ping", func(c context.Context, ctx *app.RequestContext) {
		ctx.JSON(consts.StatusOK, utils.H{"ping": "pong"})
	})

	pprof.RouteRegister(adminGroup, "pprof")

	h.Spin()
}

View pprof sampling information

Via browser

Access localhost:8888/debug/pprof via browser

  • Hertz port number defaults to 8888
  • pprof default address prefix is debug/pprof
  • The port number and access route are the same as the user’s actual port number and pprof prefix

Via go tool pprof

Use the go tool pprof tool to view stack sampling information:

go tool pprof http://localhost:8888/debug/pprof/heap

Use the go tool pprof tool to view the CPU sampling information:

go tool pprof http://localhost:8888/debug/pprof/profile

The default sampling time is 30s , and the sampling time can be customized by query string:

go tool pprof http://localhost:8888/debug/pprof/profile?seconds=10

Use the go tool pprof tool to view the blocking information of the go coroutine:

go tool pprof http://localhost:8888/debug/pprof/block

Get the execution trace information:

wget http://localhost:8888/debug/pprof/trace?seconds=5

View flame graphs with go tool pprof

Install graphviz

go tool pprof -http :8080 localhost:8888/debug/pprof/profile?seconds=10

See the full usage example


Last modified July 3, 2023 : Update response.md (0a36fb2)