Support flame graph as an output format

[aalexand]

pprof currently supports flame graph visualization in the HTTP server mode. Sometimes it is desired to generate the flame graph visualization as a persistent report, likely as an SVG file.

[ShaneHarvey]

To accomplish this right now, one has to:

1. Install go-torch: go get github.com/uber/go-torch
2. Install brendangregg/FlameGraph
3. Finally, generate the svg: go-torch -b ./profile.pprof --binaryname ./binary. (make sure FlameGraph is on your PATH)

[itczl22]

go-torch is deprecated, use pprof instead after go1.11. We can browse web ui as follow:

server nginx:

   server_name pprof.graph.com
   location / {
     proxy_pass http://127.0.0.1:8031
  }

local host:
your.server.ip pprof.graph.com

start pprof:
go tool pprof -http=:8031 "http://your.server.ip:port/debug/pprof/profile"

access local browser:
pprof.graph.com

[wyk9787]

I think the easiest way to implement this feature is to use scripts in https://github.com/brendangregg/FlameGraph and have a standalone command to indicate this is what the user wants. Is "-flamegraph" a good candidate due to the internal conflicting flag "-flame"?

[aalexand]

We should not bring in dependency on external scripts that wouldn't be a part of the executable. pprof is a part of Go runtime distribution, so everything should be contained within the pprof executable, either in the form of Go or JS code (like we do for the web UI).

[nolanmar511]

We currently use https://github.com/spiermar/d3-flame-graph as our flame graph; it would be ideal to continue to use that code.

I'm not sure of the licenses for https://github.com/brendangregg/FlameGraph. And, as aalexand noted, pprof is a part of Go, so we need to be very careful with dependencies.

[cben]

ref spiermar/d3-flame-graph#33 (but nobody ever replied there)

[cben]

How about exporting self-contained HTML? That sounds easier with d3-flame-graph than interactive SVG...
Would that satisfy the same needs?

The only reason I want SVG is to be able to send/attach a single file that co-workers can open and zoom into.

• a minor benefit of .html over .svg: it's easy to open .svg in an image viewer, or to embed it as <img> somewhere, which misses out on the zooming by JavaScript ✨, so I have to explicity recommend people to only open it in a browser (because I want them to explore it, not just take my conclusions).

[cben]

Huh, saving the HTML from the browser, in simple "just HTML" mode already works! 🎉
As does downloading it with curl:

# The redirect avoids it being suspended for reading from terminal.
go tool pprof --http :9000 --no_browser ./CMD PROFILE.heap < /dev/null &
sleep 1
for sample in {alloc,inuse}_{objects,space}; do 
  curl "http://localhost:9000/ui/?si=$sample" -o graph-$sample.html
  curl "http://localhost:9000/ui/flamegraph?si=$sample" -o flamegraph-$sample.html
  # add `source` to pages loop for annotated source view, but it's _really_ slow!
  for page in top peek disasm; do
    time curl "http://localhost:9000/ui/$page?si=$sample" -o $page-$sample.html
  done
done
kill $!

This works because data is not served in separate requests, it's simply inlined into the HTML:

pprof/internal/driver/webhtml.go

Line 1324 in 427632f

var data = {{.FlameGraph}};

(and CSS and JS are inlined too).

• So, anybody else wants a -html flag?
• Search already works too!
• Sorting by clicking columns already works!
• "Refine" menu doesn't work and probably can't as it requires backend re-computation. E.g. "Hide" reloads the page with ?h=... appended.
• The links in "View" & "Sample" menus do not work.
  • Strawman: Just drop the menu (or most of it) in export?
  • For heap, would be neat to embed all 4 sample types into one HTML, and avoid reloads when switching from menu.
  • Similar strategy could allow all visualizations to be packed into 1 HTML? Would need deeper changes... And including everything is too big & slow for most needs.

[aalexand]

I think we shouldn't bake in a requirement that the -http mode generates a single HTML page. This may easily change in the future so this seems too fragile of an assumption.

[mhansen]

Some prior art: @felixge's https://github.com/felixge/pprofutils#folded can generate "Folded Stacks" format from pprof for feeding into FlameGraph toolkit.

[fubss]

My way which I used to send FlameGraph file to my colleagues.

1. show collected data in a browser
   go tool pprof -http :8081 filename.pb.gz

2. download html page with flamegraph as a file with all data
   wget -O flamegraph.htm http://localhost:8081/ui/flamegraph