Go Fr

Advanced Guide

Using pprof in GoFr Applications

In GoFr applications, pprof profiling is automatically enabled. The profiling endpoints are served on the METRICS_PORT, which defaults to 2121 if not specified.

This guide explains how to enable and use pprof in GoFr applications.

Enabling pprof in GoFr

Prerequisites

Ensure the METRICS_PORT is set (default is 2121):

METRICS_PORT=2121

GoFr automatically registers the following pprof routes:

  • /debug/pprof/cmdline
  • /debug/pprof/profile
  • /debug/pprof/symbol
  • /debug/pprof/trace
  • /debug/pprof/ (index)

Accessing pprof Endpoints

Once pprof is enabled, you can access the profiling endpoints at http://localhost:<METRICS_PORT>/debug/pprof/. For example, if METRICS_PORT is 2121, the endpoints will be available at:

  • http://localhost:2121/debug/pprof/

Available Endpoints

  1. /debug/pprof/cmdline:

    • Returns the command-line arguments of the running application.

  2. /debug/pprof/profile:

    • Generates a CPU profile for the application.

  3. /debug/pprof/symbol:

    • Resolves program counters into function names.

  4. /debug/pprof/trace:

    • Captures an execution trace of the application.

  5. /debug/pprof/ (index):

    • Provides an index page with links to all available profiling endpoints, including memory, goroutine, and blocking profiles.

Collecting Profiling Data

1. CPU Profiling

To collect a CPU profile:

curl -o cpu.pprof http://localhost:2121/debug/pprof/profile

2. Memory Profiling

To collect a memory profile:

curl -o mem.pprof http://localhost:2121/debug/pprof/heap

3. Goroutine Profiling

To collect information about running goroutines:

curl -o goroutine.pprof http://localhost:2121/debug/pprof/goroutine

4. Execution Trace

To collect an execution trace:

curl -o trace.out http://localhost:2121/debug/pprof/trace

Analyzing Profiling Data

1. Using go tool pprof

To analyze CPU, memory, or goroutine profiles:

go tool pprof <profile_file>

top

Shows the functions consuming the most resources (e.g., CPU or memory).

go tool pprof cpu.pprof
(pprof) top

list

Displays the source code of a specific function, along with resource usage.

(pprof) list <function_name>

Example:

(pprof) list main.myFunction

web

Generates a visual representation of the profile in your browser. This requires Graphviz to be installed.

(pprof) web

2. Using go tool trace

To analyze execution traces:

go tool trace trace.out

Example Workflow

  1. Set Environment Variables:

    METRICS_PORT=2121

  2. Run Your GoFr Application:

    go run main.go

  3. Collect Profiling Data:

    • Collect a CPU profile:
      curl -o cpu.pprof http://localhost:2121/debug/pprof/profile
    • Collect a memory profile:
      curl -o mem.pprof http://localhost:2121/debug/pprof/heap

  4. Analyze the Data:

    • Analyze the CPU profile:
      go tool pprof cpu.pprof
(pprof) top
(pprof) list main.myFunction
(pprof) web
    • Analyze the memory profile:
      go tool pprof mem.pprof
(pprof) top
(pprof) list main.myFunction
(pprof) web

References

Next
Getting Started