Reporting Real-time Performance of Channels

Photo by Florian Steciuk on Unsplash

Go ships with great tools for runtime performance monitoring. However, for one of the projects I am working on I needed tailored metrics around three channels that do the primary communication between the larger components of the processing service.

I wanted to be able to print realtime stats on movement and blocking of these channels only each minute. So I created ChannelPerf :

https://gist.github.com/elliotchance/7db9eb40a935f5526b62f0bcf77b7d2c

How does it work?

For the most part it is a drop in replacement-ish with how you would normally use a channel:

// ch := make(chan interface{}, 1)
ch := NewChannelPerf(1, "Some name")

// ch <- "foo"
ch.Send("foo")

// next, ok := <-ch
next, ok := ch.Receive()

// close(ch)
ch.Close()

// for next := range ch {
//   fmt.Println(next)
// }
for {
  next, ok := ch.Receive()
  if !ok {
    break
  }
  fmt.Println(next)
}

The name (second parameter of NewChannelPerf) is used to label statistics with ch.String():

fmt.Println(ch)

Displays something like:

Some name (clock: 1.387381ms, sent: 3 in 1.745µs, received: 3 in 1.268469ms)

• clock is how long it has been tracking statistics. Statistics can…