~/Detecting and Preventing Golang Memory Leaks

Jul 14, 2022

Memory leaks in Golang occur when memory is allocated but not released, causing higher memory usage over time. Despite Go’s garbage collector, leaks can happen if references to objects are unintentionally kept.

Common causes:

• Goroutines not stopped (example)
• Slices, maps, or channels growing without bounds (slice doc)
• Global variables holding data

Detecting leaks:

• Use runtime/pprof for profiling
• pprof tool to generate heap profiles
• Libraries like uber-go/goleak detect goroutine leaks in tests

Example of a leaked goroutine:

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func leak() {
    ch := make(chan int)
    go func() {
        for {
            <-ch // blocked goroutine never released
        }
    }()
}

Prevention tips:

• Always close channels and exit goroutines
• Limit use of global variables
• Profile regularly using pprof

To learn more, see Go Memory Leaks and how to avoid them.