I’ve started using Go last month and I really liked to work with the language.

The project I’m working on is dead simple and just retrieves metrics and save on a redis server (the data will be analyzed by a different project that I’m working on). So I have 15 goroutines retrieving data constantly and I’m using just two native threads.

I did some CPU profiling on the code using my current machine for Golang 1.1.2 and 1.2 and the results can be seen below.

Golang 1.1.2:

    (pprof) top10
    Total: 188701 samples
    137454  72.8%   72.8%   137454  72.8% crypto/des.permuteBlock
    44032   23.3%   96.2%   169187  89.7% crypto/des.feistel
    3750    2.0%    98.2%   184544  97.8% crypto/des.cryptBlock
    823     0.4%    98.6%   185650  98.4% crypto/cipher.(*cbcDecrypter).CryptBlocks
    290     0.2%    98.8%      290   0.2% encoding/binary.bigEndian.PutUint64
    232     0.1%    98.9%      232   0.1% encoding/binary.bigEndian.Uint64
    227     0.1%    99.0%      227   0.1% crypto/sha1.block
    215     0.1%    99.1%      267   0.1% encoding/json.state1
    207     0.1%    99.2%      430   0.2% encoding/json.checkValid
    178     0.1%    99.3%      398   0.2% encoding/json.nextValue

    # top command result
    PID USER      PR  NI  VIRT    RES      SHR S  %CPU %MEM    TIME+  COMMAND
    18115 pothix    20   0  871800  67888   3932 S 188.8  1.7  12:40.08 crebain

    # A snapshot of the processors
    %Cpu0  :100.0 us,  0.0 sy,  0.0 ni,  0.0 id,  0.0 wa,  0.0 hi,  0.0 si,  0.0 st
    %Cpu1  : 95.0 us,  3.0 sy,  0.0 ni,  2.0 id,  0.0 wa,  0.0 hi,  0.0 si,  0.0 st

Golang 1.2:

    (pprof) top10
    Total: 6894 samples
    1686    24.5%   24.5%   1686    24.5%   crypto/aes.decryptBlockGo
    1299    18.8%   43.3%   3093    44.9%   crypto/cipher.(*cbcDecrypter).CryptBlocks
    471     6.8%    50.1%   1062    15.4%   encoding/json.checkValid
    420     6.1%    56.2%   541     7.8%    encoding/json.state1
    359     5.2%    61.4%   359     5.2%    crypto/sha1.block
    305     4.4%    65.9%   838     12.2%   encoding/json.nextValue
    245     3.6%    69.4%   274     4.0%    syscall.Syscall
    230     3.3%    72.7%   230     3.3%    encoding/json.stateBeginValue
    186     2.7%    75.4%   225     3.3%    encoding/json.stateEndValue
    156     2.3%    77.7%   156     2.3%    runtime.memmove

    top command result
    PID USER      PR  NI    VIRT    RES    SHR S  %CPU %MEM     TIME+ COMMAND
    20534 pothix    20   0  598428  51584   3532 S  12.9  1.3   0:03.76 crebain

    %Cpu0  : 12.1 us,  5.1 sy,  5.1 ni, 72.7 id,  5.1 wa,  0.0 hi,  0.0 si,  0.0 st
    %Cpu1  : 20.0 us,  4.0 sy,  0.0 ni, 75.0 id,  1.0 wa,  0.0 hi,  0.0 si,  0.0 st

What an improvement! :)

I know that this application may not be the best example to compare Go with a different language because it depends of a third application (that is my bottleneck BTW) and Ruby perform as good as the new version but I really liked to give Go a try.

Go language has a lot of interesting ideas and it is growing fast. Looks like it is a good idea of language for some of my projects, welcome Golang!