reading net/http/pprof file format (heap/cpu profile)

[fem...@googlemail.com]

Hello,


I'm trying to read the raw data net/http/pprof supplies. I've tried using protoc with the proto file that comes in github.com/google/pprof/proto/profile.proto. I'm grabbing the heap profile via  http.Get on the default endpoint. After trying to Unmarshal, the error is: 

  bad wiretype for field profiling.Profile.Mapping: got wiretype 7, want 2

I can't seem to find proper documentation on the process of reading the files, could you point me in the right direction?

greetings

[lafolle]

This is what i did:

1. Enabled net/http/pprof on server.

2. Collected cpu profile for 5s: curl http://localhost:6060/debug/pprof/profile?seconds=5 -o cpu-profile-over-http.gz

3. Copied profile.proto file from github/pprof/proto into current directory.

4. Generated profile.pb.go by: protoc profile.proto --go_out .

5. Read "cpu-profile-over-http.gz" by: go run profile.pb.go main.go,  where main.go is

package main

import (

        "compress/gzip"

        "fmt"

        "io/ioutil"

        "os"

        "github.com/golang/protobuf/proto"

)

func main() {

        f, err := os.Open("cpu-profile-over-http.gz")

        if err != nil {

                panic(err)

        }

        r, err := gzip.NewReader(f)

        if err != nil {

                panic(err)

        }

        data, err := ioutil.ReadAll(r)

        if err != nil {

                panic(err)

        }

        p := Profile{}

        err = proto.Unmarshal(data, &p)

        if err != nil {

                panic(err)

        }

        fmt.Println(p)

}

The output of which seems correct.

Did you take similar steps?  If no,  then try this.  Otherwise we would need to look at some other angle.

-----

On the other hand it seems the error you mentioned "bad wiretype for field ..." is present in v1.0.0 and not in v1.1.0 (latest) of protobuf.

https://github.com/golang/protobuf/blob/v1.0.0/proto/decode.go?utf8=%E2%9C%93#L533

If you're using old version,  consider upgrading protobuf to v1.1.0 (check releases in github)

[fem...@googlemail.com]

I didn't use gzip after fetching via `net/http`. D'oh!

thanks for the help.