Table of Contents
pprofとは
GoのProfilerで標準パッケージの一つです
わりとすんなり使えるのに高機能なので簡単に使用方法を書いていきます
今回は 「runtime/pprof」を利用する場合の方法を記述します
runtime/pprof
pprof package - runtime/pprof - Go Packages
まずプロファイリングデータをドキュメントのexampleを参考に取得します
下記コードの場合、「// ... rest of the program ...」部分のコードのプロファイリングデータを作成します
var cpuprofile = flag.String("cpuprofile", "", "write cpu profile to `file`")
var memprofile = flag.String("memprofile", "", "write memory profile to `file`")
func main() {
flag.Parse()
if *cpuprofile != "" {
f, err := os.Create(*cpuprofile)
if err != nil {
log.Fatal("could not create CPU profile: ", err)
}
defer f.Close()
if err := pprof.StartCPUProfile(f); err != nil {
log.Fatal("could not start CPU profile: ", err)
}
defer pprof.StopCPUProfile()
}
// ... rest of the program ...
if *memprofile != "" {
f, err := os.Create(*memprofile)
if err != nil {
log.Fatal("could not create memory profile: ", err)
}
defer f.Close()
runtime.GC() // get up-to-date statistics
if err := pprof.WriteHeapProfile(f); err != nil {
log.Fatal("could not write memory profile: ", err)
}
}
}
上記コードの場合は、cpuprofileを出したい時は 「-cpuprofile プロファイリングファイル名」
memoryを出したい時は「-memprofile プロファイリングファイル名」のオプションを付けて実行します
$ go build -o playground
$ ./playground -cpuprofile cpu_info
その後プロファイリングファイルをpprofのツールに読み込ませます
読み込ませ方は「go tool pprof 実行ファイル名 プロファイリングファイル名」です
$ go tool pprof playground cpu_info
File: playground
Type: cpu
Time: Jul 7, 2019 at 7:34pm (JST)
Duration: 15.38s, Total samples = 36.01s (234.10%)
Entering interactive mode (type "help" for commands, "o" for options)
対話式の画面になるので 「top 10」と入力してみます。
すると実行時間が長い順にソートされた状態で結果が出力されます。
(pprof) top 10
Showing nodes accounting for 34.39s, 95.50% of 36.01s total
Dropped 52 nodes (cum <= 0.18s)
Showing top 10 nodes out of 51
flat flat% sum% cum cum%
12.80s 35.55% 35.55% 12.83s 35.63% runtime.pthread_cond_wait
8.10s 22.49% 58.04% 8.10s 22.49% runtime.pthread_cond_signal
4.82s 13.39% 71.42% 4.82s 13.39% runtime.(*semaRoot).queue
3.83s 10.64% 82.06% 3.84s 10.66% runtime.usleep
3.23s 8.97% 91.03% 3.50s 9.72% syscall.syscall
0.86s 2.39% 93.42% 0.86s 2.39% internal/poll.(*pollDesc).prepare
0.23s 0.64% 94.06% 0.24s 0.67% runtime.exitsyscallfast
0.21s 0.58% 94.64% 3.67s 10.19% runtime.runqgrab
0.17s 0.47% 95.11% 0.19s 0.53% runtime.pthread_mutex_unlock
0.14s 0.39% 95.50% 17.32s 48.10% runtime.findrunnable
その他の利用方法は「help」を叩いてみてください
(pprof) help
Commands:
callgrind Outputs a graph in callgrind format
comments Output all profile comments
disasm Output assembly listings annotated with samples
dot Outputs a graph in DOT format
eog Visualize graph through eog
evince Visualize graph through evince
gif Outputs a graph image in GIF format
gv Visualize graph through gv
kcachegrind Visualize report in KCachegrind
list Output annotated source for functions matching regexp
pdf Outputs a graph in PDF format
peek Output callers/callees of functions matching regexp
png Outputs a graph image in PNG format
proto Outputs the profile in compressed protobuf format
ps Outputs a graph in PS format
raw Outputs a text representation of the raw profile
svg Outputs a graph in SVG format
tags Outputs all tags in the profile
text Outputs top entries in text form
top Outputs top entries in text form
topproto Outputs top entries in compressed protobuf format
traces Outputs all profile samples in text form
tree Outputs a text rendering of call graph
web Visualize graph through web browser
weblist Display annotated source in a web browser
o/options List options and their current values
quit/exit/^D Exit pprof
Options:
call_tree Create a context-sensitive call tree
compact_labels Show minimal headers
divide_by Ratio to divide all samples before visualization
drop_negative Ignore negative differences
edgefraction Hide edges below <f>*total
focus Restricts to samples going through a node matching regexp
hide Skips nodes matching regexp
ignore Skips paths going through any nodes matching regexp
mean Average sample value over first value (count)
nodecount Max number of nodes to show
nodefraction Hide nodes below <f>*total
noinlines Ignore inlines.
normalize Scales profile based on the base profile.
output Output filename for file-based outputs
prune_from Drops any functions below the matched frame.
relative_percentages Show percentages relative to focused subgraph
sample_index Sample value to report (0-based index or name)
show Only show nodes matching regexp
show_from Drops functions above the highest matched frame.
source_path Search path for source files
tagfocus Restricts to samples with tags in range or matched by regexp
taghide Skip tags matching this regexp
tagignore Discard samples with tags in range or matched by regexp
tagshow Only consider tags matching this regexp
trim Honor nodefraction/edgefraction/nodecount defaults
trim_path Path to trim from source paths before search
unit Measurement units to display
Option groups (only set one per group):
cumulative
cum Sort entries based on cumulative weight
flat Sort entries based on own weight
granularity
addresses Aggregate at the address level.
filefunctions Aggregate at the function level.
files Aggregate at the file level.
functions Aggregate at the function level.
lines Aggregate at the source code line level.
: Clear focus/ignore/hide/tagfocus/tagignore
type "help <cmd|option>" for more information
ビジュアライズするのも簡単です。
「web」と打ち込むだけで関数の関係性をビジュアライズしてくれます。
(pprof) web
まとめ
簡単にでしたがpprofのご紹介でした。
何が原因かわからないけどパフォーマンスが出ない、メモリを使い過ぎている際など
ドンドン使っていきたいパッケージのご紹介でした。
shiro seike / せいけ しろう / 清家 史郎
Company：Fusic CO., LTD. Slides：slide.seike460.com blog：blog.seike460.com Program Language：PHP , Go Interest：Full Serverless Architecture
