memgc

Simple continuous memory info aggregator from GoLang gc trace

A single cycle of GC Trace looks like:

gc 3 @3.182s 0%: 0.015+0.59+0.096 ms clock, 0.19+0.10/1.3/3.0+1.1 ms cpu, 4->4->2 MB, 5 MB goal, 12 P

This line is printed every time the Go garbage collector runs and shows detailed metrics about that specific GC cycle.

Data Aggregation

Installation:

go install github.com/kunalsin9h/memgc@latest

Usage:

GODEBUG=gctrace=1 ./bin 2> >(memgc --csv data.csv)

This will output a data.csv file.

Visualization

Load the data.csv file in graph plotting tools like Draxlr

CPUPercent

Shows "Total percentage of CPU time spent in GC since the program started"

If this number keeps increasing, it means GC overhead is increasing - possibly due to memory leaks or excessive allocations.

HeapInUseBefore

Tells how much heap memory in use before that GC cycle.

HeapMarkedLive

Live Heap = Memory that is actually reachable and in use by your program after GC completes.

If this value is keeping increasing and not degreasing (i.e next GC cycle is not cleaning it) that means we have memory leak

Reference

• Continuous Memory Plotting from GC Trace

• GC Trace Format