benchmark

profiling

source go test -bench=. -benchmem -cpuprofile=cpu.out -memprofile=mem.out bench_test.go

go tool pprof -alloc_space mem.cputest mem.out (pprof) list ‘func name’

go build -gcflags “-m -m”

profiling example

source get data from pprof debug endpoint $ curl http://localhost:8080/debug/pprof/profile?seconds=29 > cpu.1000_reqs_sec_no_optimizations.prof

show in local webserver $ go tool pprof -http=:12345 cpu.1000_reqs_sec_no_optimizations.prof

benchcmp

go test -bench=. -benchmem bench_test.go > new.txt git stash go test -bench=. -benchmem bench_test.go > old.txt benchcmp old.txt new.txt

benchmark old ns/op new ns/op delta
BenchmarkToJSON 1579 495 -68.65%

benchmark old MB/s new MB/s speedup BenchmarkToJSON 12.66 46.41 3.67x

benchmark old allocs new allocs delta BenchmarkToJSON 2 2 +0.00%

benchmark old bytes new bytes delta BenchmarkToJSON 184 48 -73.91%

debuger

graphical delve?

dlv debug main.go # eq go run
dlv exec # debug compiled bin
dlv test # eq go test
dlv attach # debug running app
dlv trace #

dlv cli> break file:num # define break point
dlv cli> continue #run till break point alias c
dlv cli> locals #show vars
dlv cli> step # execute next line
dlv cli> next # Step over to next source line.
dlv cli> stepout # execute till return and stop
dlv cli> restart # restart app with debug and all breakpoints

dlv cli>source path # execute dlv commands from file defined in path separated by newline
dlv cli> frame 0 locals # show locals in 0 frame goroutine

dlv variables cmd:

• locals in current func
• print specific var
• args shows args current function
• vars all package level vars
• funcs
• types

dlv

• sources list all sources files
• list code around line executed or we can specify line in source file currently executing like ‘list 50’
• disassemble
• regs shows CPU registers

dlv get app state

• stack
• goroutines #shows all goroutines flag -g shows place of goroutine creation
• treads

dlv manipulate app state

• set # changes var value
• goroutine #change goroutine
• tread #change active thread

dlv app halt cmd

• break break main.go:2 app stops just BEFORE line 2
• condition condition breakpoint ID condition itself
• trace #not halting but logging trace label main.go
• breakpoints #list breakpoints
• on
• clear
• clearall

TODO delve