私がGoを選択する理由 / Geek Salon Vol.7

Transcript

1. ࢲ͕GoΛબ୒͢Δཧ༝
   Tatsuhiko Kubo@cubicdaiya
   Geek Salon vol.7@2015/05/29
   

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2. ࣗݾ঺հ
   • ٱอୡ඙(Tatsuhiko Kubo)
   • bokko@cubicdaiya
   • Software Engineer in Infrastructure Engineering
   • Mercari, Inc.
   • Favorites: Go, C, Lua, nginx
   

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3. GoͰ৭Μͳ΋ͷͭͬͯ͘·͢
   • nginx-build - nginxͷϏϧυπʔϧ
   • cachectl - OSͷϖʔδΩϟογϡ੍ޚπʔϧ
   • slackboard - SlackϓϩΩγαʔό
   • gaurun - ϓογϡ௨஌ϓϩΩγαʔό
   શ෦ϝϧΧϦͷதͰ࢖ΘΕ͍ͯ·͢
   

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4. GoҎ֎Ͱར༻ܦݧͷ͋Δݴޠ
   • ϓϩμΫγϣϯͰͷར༻ܦݧ͋Γ
   • C, C++, Lua, PHP, Python, JavaScript
   • JavaScriptͱC++͸΋͏΄ͱΜͲ๨Ε·ͨ͠…
   • ৮ͬͨ͜ͱ͋ΔϨϕϧ
   • Perl, Ruby, Scheme, Haskell, Erlang, Scala, etc…
   

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5. C, C++Ͱͷ։ൃܦݧ
   • neoagent - memcachedϓϩΩγαʔό
   • ngx_small_light - ը૾ม׵༻nginxϞδϡʔϧ
   • dtl - diffϥΠϒϥϦ
   • OSSʹͳͬͯͳ͍ੲͷ͓࢓ࣄ
   • e.g. ϨίϝϯυΤϯδϯɺ૊ΈࠐΈιϑτ΢ΣΞɺ
   ޿ࠂ഑৴γεςϜɺetc…
   

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6. LLͰͷ։ൃܦݧ
   • WebαʔϏεͷ։ൃɾӡ༻
   • e.g. ϑΥτଂ, ·ͪͭ͘, pixiv, ϝϧΧϦ
   • PHP͕ϝΠϯ
   • ͦͷଞࡉʑͱͨ͠CLIπʔϧΛͨ·ʹPython΍
   Ruby౳Ͱॻ͍ͯ·ͨ͠
   

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7. ݱࡏͷཱͪҐஔͱ͍͏͔ओͳ࢓ࣄ
   • ϛυϧ΢ΣΞͷ։ൃɾӡ༻
   • ֤ॴʹnginxͱGoΛಋೖͯ͠༡Ϳ࠷దԽ
   • Ansible, Fluentd, Elasticsearch, etc…
   • ͦͷଞࡶଟͳӡ༻޲͚CLIπʔϧͷ։ൃ
   • rootݖݶ͕ඞཁͳ࢓ࣄશൠ
   • ҰൠʹΠϯϑϥΤϯδχΞͱݺ͹ΕΔ࢓ࣄ
   

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8. CͰ͸ͳ͘GoΛબ୒͢Δཧ༝
   • (গͳ͘ͱ΋CΑΓ͸)ੜ࢈ੑ͕ߴ͍
   • ϝϞϦ؅ཧͷ༰қ͞(ΨϕʔδίϨΫγϣϯ)
   • ڧྗͳฒߦॲཧͷαϙʔτ(ΰϧʔνϯ)
   • ΋͏ϚϧνεϨουϓϩάϥϜͷσόοά͢ΔͷźŦƄɾɾɾ
   • Ϗϧυ͕؆୯
   • े෼ͳύϑΥʔϚϯε(جຊCͷํ͕଎͍͕ɺGoͰे෼ͳ৔߹΋
   ଟ͍)
   

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9. LLͰ͸ͳ͘GoΛબ୒͢Δཧ༝
   • ߴ͍ύϑΥʔϚϯε & ϑοτϓϦϯτ͕খ͍͞
   • LLͱൺ΂Δͱ͔ͳΓ଎͍
   • ڧྗͳฒߦॲཧͷαϙʔτ(ΰϧʔνϯ)
   • ഑෍ͷ༰қ͞(ΫϩείϯύΠϧɺ୯ҰόΠφϦ)
   • CLIπʔϧͷ࡞੒ɾ഑෍ɾӡ༻ָ͕
   

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10. ࣮ྫ
    

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11. nginx-build
    

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12. nginx-build
    • nginxͷϏϧυπʔϧ
    • nginxͷϏϧυʹ·ͭΘΔ໘౗ࣄΛࣗಈԽ
    • ιʔείʔυ΍ґଘϥΠϒϥϦͷμ΢ϯϩʔυ
    • 3rd PartyϞδϡʔϧͷμ΢ϯϩʔυɺ૊ΈࠐΈ
    • https://github.com/cubicdaiya/nginx-build
    

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13. Why is nginx-build written in Go?
    • ࠷ॳ͸shͰॻ͍ͯͨ
    • ੲ͍ͨձࣾʹ͸શࣗಈԽsh͕͋ͬͨ
    • స৬ͯ͠࢖͑ͳ͘ͳͬͨ
    • ·ͨshॻ͘ͷͭΒ͍͠ɺϝϯς΋ͨ͘͠ͳ͍
    • ͦ͏ͩɺGoͰॻ͜͏ʂ
    

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14. Why is nginx-build written in Go?
    • ϙʔλϒϧ
    • ϝϯςָ͕
    • ഑෍΋ָ
    • ΫϩείϯύΠϧ͕؆୯
    • ฒྻॲཧ͕؆୯
    

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15. nginx-buildͷ࣮ߦ෩ܠ
    $ nginx-build -d work -pcre -zlib -openssl
    nginx-build: 0.3.1
    Compiler: gc go1.4.1
    2015/03/10 02:04:23 Download pcre-8.36.....
    2015/03/10 02:04:23 Download zlib-1.2.8.....
    2015/03/10 02:04:23 Download openssl-1.0.2.....
    2015/03/10 02:04:23 Download nginx-1.7.10.....
    2015/03/10 02:04:28 Extract zlib-1.2.8.tar.gz.....
    2015/03/10 02:04:28 Extract nginx-1.7.10.tar.gz.....
    2015/03/10 02:04:35 Extract openssl-1.0.2.tar.gz.....
    2015/03/10 02:04:39 Extract pcre-8.36.tar.gz.....
    2015/03/10 02:04:39 Generate configure script for nginx-1.7.10.....
    2015/03/10 02:04:39 Configure nginx-1.7.10.....
    2015/03/10 02:04:45 Build nginx-1.7.10.....
    2015/03/10 02:07:34 Complete building nginx!
    ɾ
    ɾ
    ɾ
    $
    ฒྻͰ࣮ߦ͞Ε·͢
    

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16. ͜Μͳײ͡
    parallels := 0
    done := make(chan bool)
    (தུ)
    if *pcreStatic {
    parallels++
    go downloadAndExtractParallel(&pcreBuilder, done)
    }
    if *openSSLStatic {
    parallels++
    go downloadAndExtractParallel(&openSSLBuilder, done)
    }
    if *zlibStatic {
    parallels++
    go downloadAndExtractParallel(&zlibBuilder, done)
    }
    parallels++
    go downloadAndExtractParallel(&nginxBuilder, done)
    (தུ)
    for i := 0; i < parallels; i++ {
    <-done
    }
    

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17. shΑΓͣͬͱָͰ͢
    

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18. cachectl
    

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19. cachectl
    • OSͷϖʔδΩϟογϡ֬ೝɾ࡟আπʔϧ
    • ແବͳϖʔδΩϟογϡΛղ์͢Δͷʹར༻
    • cachectld͍ͬͯ͏σʔϞϯ΋෇͍ͯΔ
    • https://github.com/cubicdaiya/cachectl
    

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20. Why is cachectl written in Go?
    • طଘͷπʔϧ͕࢖͍ʹ͔ͬͨ͘
    • e.g. σΟϨΫτϦࢦఆ͕Ͱ͖ͳ͍
    • σʔϞϯԽͯ͠ఆظతʹ࣮ߦ͔͚ͨͬͨ͠ͲɺͦΜͳػ
    ೳ࣋ͬͯΔπʔϧ͕ͳ͔ͬͨ
    • γεςϜίʔϧ͕cgo΍syscallͰ؆୯ʹݺͼग़ͤΔ
    • ϖʔδΩϟογϡͷ৘ใऔಘ΍ղ์ʹ͸mmap΍
    mincoreɺposix_fadvise౳ͷγεςϜίʔϧ͕ඞཁ
    

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21. cachectlͰϖʔδΩϟογϡͷ
    ར༻۩߹ΛνΣοΫ
    $ cachectl -f /var/log/nginx/access.log
    2015/03/10 03:08:37 /var/log/nginx/
    access.log 's pages in cache:
    1323464/1323464 (100.0%)
    [filesize=5293852.1K, pagesize=4K]
    $
    5GBͷϩάϑΝΠϧͷத਎͕
    શ෦ϖʔδΩϟογϡʹࡌͬͯΔ
    

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22. ফͯ͠ΈΔ
    $ # ϖʔδΩϟογϡΛ࡟আ
    $ cachectl -f /var/log/nginx/access.log -op purge
    2015/03/10 03:13:03 purging /var/log/nginx/
    access.log 's page cache
    $
    $ # ࠶౓ϖʔδΩϟογϡͷར༻۩߹ΛνΣοΫ
    $ cachectl -f /var/log/nginx/access.log
    2015/03/10 03:13:07 /var/log/nginx/access.log 's
    pages in cache: 94/1325181 (0.0%)
    [filesize=5300722.2K, pagesize=4K]
    $
    5GBͷϝϞϦ͕ղ์͞Ε·ͨ͠
    

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23. ࢦఆͨ͠ϑΝΠϧͷϖʔδΩϟογϡΛղ์͢ΔCͷؔ਺
    /*
    #include
    #include
    #include
    #include
    int fadvise(const char *path, float r)
    {
    int fd;
    struct stat st;
    off_t l;
    fd = open(path, O_RDONLY);
    if(fd == -1) {
    return -1;
    }
    if(fstat(fd, &st) == -1) {
    goto error;
    }
    l = (off_t)(st.st_size * r);
    if(posix_fadvise(fd, 0, l, POSIX_FADV_DONTNEED) != 0) {
    goto error;
    }
    close(fd);
    return 1;
    error:
    close(fd);
    return -1;
    }
    */
    import "C"
    

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24. Go͔Βͷݺͼग़͠
    func purgePages(fpath string, fsize int64, rate float64) error {
    if rate < 0.0 || rate > 1.0 {
    return errors.New(fmt.Sprintf("%f: rate should be less than 1.0\n", rate))
    }
    cs := C.CString(fpath)
    defer C.free(unsafe.Pointer(cs))
    result := C.fadvise(cs, C.float(rate))
    if result == -1 {
    return errors.New(fmt.Sprintf("failed to purge page cache for %s", fpath))
    }
    return nil
    }
    C.(ؔ਺໊)Ͱݺͼग़ͤΔ
    

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25. slackboard
    

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26. slackboard
    • SlackϓϩΩγ
    • clientίϚϯυ(slackboard-cli)෇ଐ
    • ࠷ۙcronlogͬΆ͍ͷΛ௥Ճ(slackboard-log)
    • https://github.com/cubicdaiya/slackboard
    

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27. Why is slackboard written in Go?
    • net/httpͰ؆୯ʹHTTPαʔό/ΫϥΠΞϯτ͕ॻ
    ͚Δ
    • slackboard-cli͸શαʔόʹ഑ஔ͍ͨ͠
    • GoͳΒ഑෍ָ͕
    • LLΈ͍ͨʹ֤αʔόʹ࣮ߦ؀ڥ༻ҙ͠ͳ͍͍ͯ͘
    

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28. ࣮ߦΠϝʔδ
    

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29. gaurun
    

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30. gaurun
    • ൚༻ϓογϡ௨஌αʔό
    • ୹࣌ؒͰ਺ेɺ਺ඦສ݅ͷϓογϡ௨஌͕Մೳ
    • HTTPͱJSONΛϕʔεʹͨ͠γϯϓϧͳAPI
    • https://github.com/mercari/gaurun
    

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31. ϝϧΧϦͷϓογϡ௨஌γεςϜ
    PS
    CBUDIαʔό
    

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32. Why is gaurun written in Go?
    • net/httpͰ؆୯ʹHTTPαʔό/ΫϥΠΞϯτ͕
    ॻ͚Δ
    • ڧྗͳฒߦॲཧͷαϙʔτ
    • ୹࣌ؒͰޮ཰Α͘ϓογϡ௨஌͢Δʹ͸ฒ
    ߦੑͷߴ͍ݴޠ͕ඞཁ
    

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33. ·ͱΊ
    • ੲ͸C΍LLͰॻ͍ͯͨ΋ͷ΋ࠓͰ͸GoͰॻ͘Α͏ʹͳ
    Γ·ͨ͠
    • ҎԼͦͷཧ༝
    • े෼ͳύϑΥʔϚϯεͱϑοτϓϦϯτͷখ͞͞
    • ڠྗͳฒߦॲཧͷαϙʔτ(ΰϧʔνϯ)
    • Ϗϧυɾ഑෍ͷ༰қ͞
    

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