gateway.go_debug

The GODEBUG environment variable can be used to enable the instrumentation described in the runtime package. (search that page for GODEBUG for a full explanation)

In particular, you can set:

GODEBUG=gctrace=1 

which will enabled detailed GC tracing entries to appear in the sync gateway log files:

gc14(8): 9+35+598+167 us, 2 -> 5 MB, 12033 (41461-29428) objects, 24 goroutines, 417/297/0 sweeps, 41(508) handoff, 6(9) steal, 301/43/1 yields
gc15(8): 4+672+13+179 us, 2 -> 5 MB, 11234 (42750-31516) objects, 24 goroutines, 422/245/0 sweeps, 30(478) handoff, 7(11) steal, 294/62/9 yields
gc16(8): 10+43+736+5 us, 2 -> 5 MB, 11751 (44627-32876) objects, 23 goroutines, 423/196/0 sweeps, 22(406) handoff, 7(9) steal, 291/39/3 yields

In order to use this, you can add a parameter to the "override" as follows:

gateway.go_debug.gctrace=1

If you wanted multiple values, you can comma separate them (not tested yet)

gateway.go_debug.gctrace=1,schedtrace=50

A working example can be found in perf run 706