How to profile your Golang Fiber server

Usually you need to load test your webserver to measure where's the memory leak or where's the bottleneck, and Golang already provided tool to do that, called pprof. What you need to do is depends on your framework that you use, but it's all similar, most framework already have a middleware that you can import and use, for example in fiber there's pprof middleware, to use:

// import

  "github.com/gofiber/fiber/v2/middleware/pprof"

// use
  app.Use(pprof.New())

It would create a route called /debug/pprof that you can use, just start the server, then open that path. To profile or check heap you just need to click profile/heap link, it would wait for around 10 seconds, meanwhile it waits, you must hit other endpoints to generate traffic/function calls. After 10 seconds, it would show a download dialog to save your cpu profile or heap profile. From that file, you can run a command similar to gops, for example if you want to generate svg or generate web that shows your profiling:

pprof -web /tmp/profile # or
pprof -svg /tmp/profile # <-- file that you just downloaded

It would generate something like this:

So you can find out which function that took most of the CPU time (or if it's heap profile, which function that generates/allocate most memory usage. In my case the bottleneck is the default built-in pretty logger, it limits the number of requests it can only handle to ~9K rps for concurrency 255 on database write benchmark, that if we remove built-in logging and replace with zerolog, it can handle ~57K rps for same benchmark.