kingkai generates HTTP benchmark reports by comparing past and future attacks made by vegeta.

He possesses great intelligence and knowledge about the universe, and specializes in universal telepathic links. Even though he was already weaker than Vegeta before he taught Goku, King Kai is still a veritable library of skills, techniques and literally centuries of wisdom. (source)

Install Go, then run:

go get -u github.com/slimsag/kingkai

First use vegeta attack to produce some before and after gob files:

$ mkdir before
$ echo "GET https://google.com" | vegeta attack -duration=5s -name 'Google.com @ 50 QPS / 5s' > before/query1.bin

$ mkdir after
$ echo "GET https://google.com" | vegeta attack -duration=5s -name 'Google.com @ 50 QPS / 5s' > after/query1.bin

$ tree before/ after/
before/
└── query1.bin
after/
└── query1.bin

0 directories, 2 files

Then make use of kingkai:

$ kingkai before/ after/

Which outputs the following Markdown result:

Google.com @ 2 QPS / 30s

Mean	P50	P95	P99	Max	Success Ratio
178ms → 142ms (-20.22%)	131ms → 130ms (-0.76%)	436ms → 167ms (-61.70%)	517ms → 613ms (18.57%)	523ms → 655ms (25.24%)	1% → 1%

@Andoryuuta for helping to write this all while 🛶 Canoeing across the atlantic.