はてなにおけるマイクロサービスとScala / Microservices and Scala at Hatena

Scala関西Summit 2016 (http://summit.scala-kansai.org/) の発表資料です。

1. ͸ͯͳʹ͓͚Δ ϚΠΫϩαʔϏεͱScala id:aereal
2. ࣗݾ঺հ • id:aereal • גࣜձࣾ͸ͯͳ (2012ʙ) • ͸ͯͳϒοΫϚʔΫ • ͸ͯͳϒϩά • Perl, Ruby, Scala, Shell Script
3. ΞδΣϯμ • ৽ (ϚΠΫϩ) αʔϏεʹ͍ͭͯ • ͳͥϚΠΫϩαʔϏε͔ • ͳͥScala͔ • DDDͷ࣮ફ
4. DISCLAIMER • ։ൃதͷ಺༰ؚ͕·Ε·͢ • ࣮ࡍͷϦϦʔε࣌ʹ͸มߋ͞Ε͍ͯΔՄೳੑ͋Γ
5. ৽αʔϏεʹ͍ͭͯ
6. http://hatenablog.com/
7. “͸ͯͳϒϩάΛ΋ͬͱຊ֨తʹ࢖͍͍ͨํͷͨ Ίʹɺ༗ྉϓϥϯʮ͸ͯͳϒϩάProʯΛ༻ҙ͠ ͓ͯΓ·͢ɻ޿ࠂͷඇදࣔ΍ಠࣗυϝΠϯػೳ ͳͲɺ͸ͯͳϒϩάΛΑΓศརʹ͓࢖͍͍ͨͩ ͚·͢ɻ” http://hatenablog.com/guide/pro
8. ͸ͯͳϙΠϯτ ΫϨδοτΧʔυ ίϯϏχৼࠐ ۜߦৼࠐ ࢖༻ https://www.hatena.ne.jp/shop/point/list
9. http://hatena.g.hatena.ne.jp/hatena/20150529/1432869070
10. վम or ࡞Γ௚͠ • طଘͷγεςϜ͸ϞϊϦγοΫ • ܾࡁͯ͠͸ͯͳϙΠϯτΛνϟʔδ͢Δ • ͸ͯͳϙΠϯτΛ࢖ͬͯߪೖ͢Δ • ࢓༷Λ੔ཧ͢Δ͍͍ػձͰ΋͋Δ
11. ܾࡁ୅ߦαʔϏε
 (֎෦) ͸ͯͳͷαʔϏε (ϒοΫϚʔΫͳͲ) ݱߦܾࡁγεςϜ ϙΠϯτ؅ཧ ڞ༗Ϟδϡʔϧ ༗ྉϓϥϯ؅ཧ ґଘ ͸ͯͳͷαʔϏε ґଘ ͸ͯͳͷαʔϏε ґଘ etc. ΞΧ΢ϯτ
12. ݱߦܾࡁγεςϜͷߏ੒ • ܾࡁγεςϜ: WebΞϓϦέʔγϣϯ • API͸ͳ͘HTMLͷϑΥʔϜ͕͋ΔͷΈ • ڞ༗Ϟδϡʔϧ: ܾࡁ୅ߦαʔϏεͱ௨৴͢Δ࣮૷ • ͨ͘͞ΜͷϦϙδτϦ͔Βґଘ͞Ε͍ͯΔ • ڞ༗DBΛૢ࡞͢Δ
13. ݱߦܾࡁγεςϜͷվम • ΄ͱΜͲݱ࣮తͰ͸ͳ͍ • ޓ׵ੑʹؔ͢ΔεΩʔϜ͕ͳ͍ • ׬શޙํޓ׵ or die • ෳ਺ͷυϝΠϯ͕ೖΓཚΕ͍ͯΔ • ݱࡏͷ࢓༷ʹӨڹΛڧ͘ड͚Δ • վળ͕·ΘΒͳ͍
14. ϑϧεΫϥον
15. ৽ܾࡁγεςϜ • ܾࡁ୅ߦαʔϏεͷήʔτ΢ΣΠͱͯ͠ಇ͘ • ͸ͯͳϒϩάProͷ෇༩ͳͲ͸֤αʔϏεʹҠৡ • JSON over HTTPͳAPIͷΈΛఏڙ͢Δ • ର৅͸SSKDs (= small set of known developers)
16. ৽ܾࡁγεςϜ
 ߏ੒ਤ ܾࡁ୅ߦαʔϏε
 (֎෦) ͸ͯͳͷαʔϏε ༗ྉϓϥϯͷ ঢ়ଶ؅ཧ ৽ܾࡁγεςϜ
17. چ ৽
18. ׬
19. ͳͥϚΠΫϩαʔϏε͔
20. ϚΠΫϩαʔϏεͰ࡞Δ͔ • 1ʙ3ষʹ͔͚ͯϝϦοτ΍ ʮ༏ΕͨαʔϏεʯʹ͍ͭͯ ड़΂ΒΕ͍ͯΔ • ϚΠΫϩαʔϏεʹΑͬͯ
 αʔϏε͸ΑΓΑ͘ͳΔͷ͔ • ΨόφϯεͳͲɺ
 ίετ͸෷͑ΔͩΖ͏͔ https://www.oreilly.co.jp/books/9784873117607/
21. ૄ݁߹ͱߴڽूੑ 1. ϞϊϦγοΫͰखΛೖΕͮΒ͍ (ີ݁߹) 2. ৽ͨʹ༗ྉϓϥϯΛಋೖ͍ͨ͠αʔϏε͸࠶࣮૷ 3. υϝΠϯ஌͕ࣝྲྀग़ (௿ڽूੑ) 4.
22. ࣋ଓՄೳʹ࡞Γ (ͳ͓͠) ͍ͨ • είʔϓΛখ͘͞໌ྎʹอͭ • ૄ݁߹ (ʰϚΠΫϩαʔϏεΞʔΩςΫνϟʱ3.2.1) • ߴڽूੑ (ʰϚΠΫϩαʔϏεΞʔΩςΫνϟʱ3.2.2) • ෼ׂ౷࣏͢Δ • ٕज़ҟ࣭ੑ (͍ͭ·Ͱ΋Perl͸ݫ͍͠) • σϓϩΠͷϥΠϑαΠΫϧΛૣΊΔ
23. νʔϜؒ࿈ܞͷ
 Ή͔ͣ͠͞ͱઓ͏
24. ΠϯηϓγϣϯσοΩΛ࡞Δ • ۙ͝ॴ͞ΜΛ໌Β͔ʹ͢Δ • ϝϯς͸Ͳ͜ʹҾ͖ܧ͙ͷ͔ • ԿΛ༏ઌ͢Δͷ͔ (ఘΊΔͷ͔) Λ͸͖ͬΓͤ͞Δ • είʔϓɺ඼࣭ɺ༧ࢉɺεέδϡʔϧ • ʰΞδϟΠϧαϜϥΠʱ
25. ͳͥϚΠΫϩαʔϏε͔: ·ͱΊ • ࠓճ͸ϚΠΫϩαʔϏεͰ΍͍ͬͯ͘ • ಘΒΕΔϝϦοτ > ෷͏ίετ • ΨόφϯεͳͲෆ҆ͳ఺ʹ΋खΛଧͭ • ΠϯηϓγϣϯσοΩ • ૣ͔͘Βר͖ࠐΉ
26. ׬
27. ͳͥScala͔
28. ࣮૷ݴޠΛܾΊΔ • ͸ͯͳͷબ୒ࢶͱͯ͠͸Perl, Go, ͦͯ͠Scala • ৽ܾࡁγεςϜͷίΞυϝΠϯʹٕज़ͦͷ΋ͷ͸
 ؚ·Εͳ͍ • ϦεΫΛͱͬͯଞͷ৽ͨͳݴޠΛ࠾༻͢Δ
 ϝϦοτ͸ബ͍
29. ࣮૷ݴޠΛܾΊΔ • ͳʹ͔ࢦඪ͕΄͍͠ • ؾ࣋ͪ͸͍Ζ͍Ζ͋Δ • ʮ޷͖͔ͩΒʯͰ΋͍͍͚Ͳ…… • ͲΜͳPros/ConsΛݟͨͷ͔
30. ඇػೳཁٻΛఆΊΔ • ISO 9126 • functionality: ػೳੑ • reliability: ৴པੑ • usability: ࢖༻ੑ • efficiency: ޮ཰ੑ • maintainability: อकੑ • portability: Ҡ২ੑ
31. ඇػೳཁٻΛఆΊΔ • ISO 9126 • functionality: ػೳੑ • reliability: ৴པੑ • usability: ࢖༻ੑ • efficiency: ޮ཰ੑ • maintainability: อकੑ • portability: Ҡ২ੑ
32. ݴޠΛબͿ্ͰٻΊΔ΋ͷ • ๛͔ͳදݱྗ • ෳࡶͳυϝΠϯΛաෆ଍ͳ͘දݱ͍ͨ͠ • ֶशۂઢͷ؇΍͔͞ • ։ൃεϐʔυΛૣΊʹߴΊ҆ఆ͍ͤͨ͞ • কདྷɺ։ൃ͢Δਓʹ΋΍͘͞͠
33. ෳࡶͳυϝΠϯ • ঢ়ଶ΍ߟྀ͢΂͖ม਺͕ೖΓ૊ΜͰ͍Δ • ΫϨδοτΧʔυͷ༗ޮظݶ͕੾Ε͍ͯͨΒ? • ܾࡁ୅ߦαʔϏε͕མ͍ͪͯͨΒ?
34. ঢ়ଶΛྻڍܕͰදݱ͢Δ sealed trait State object State { case object Requested extends State case object Paid extends State case object Failed extends State } ※࣮ࡍ͸΋͏ͪΐͬͱ͍Ζ͍Ζ͋Γ·͢
35. ঢ়ଶΛྻڍܕͰදݱ͢Δ case class Payment(state: State) { def charged: Boolean = state match { case State.Paid => true case _ => false } }
36. ঢ়ଶΛྻڍܕͰදݱ͢Δ • sealedम০͢ΔͱmatchࣜͰ໢ཏੑνΣοΫͰ͖Δ • ͱΓ͏Δঢ়ଶʹ໊͍ͭͯલΛ༩͑ΒΕΔ • ʮPaid͔FailedʹͳͬͨΒͦͷPayment͸
 ऴ୺͠·͢Ͷʯ
37. Scalaͷֶशۂઢ……? • ؇΍͔Ͱ͸ͳ͍! (ݸਓͷݟղ) • ͔͠͠͸ͯͳͰ͸ࢧԉ͢Δ؀ڥΛ੔͖͑ͯͨ • ࣄྫ (Mackerel, ͸ͯͳϒοΫϚʔΫϦχϡʔΞϧ) • ͸ͯͳڭՊॻ github.com/hatena/Hatena-Textbook • ScalaͷఆੴΛ୳Δձ
38. ScalaͷఆੴΛ୳Δձ • ϥΠϒϥϦ΍࣮૷ύλʔϯͷ஌ݟΛ࣋ͪدΔ • ScalaΛ࢖͍ͬͯΔνʔϜͷ༗ࢤͰ։࠵ • Mackerel • ϒοΫϚʔΫϦχϡʔΞϧ • ৽ܾࡁγεςϜ
39. ఆੴΛ୳ΔձͰ࿩ͨ͜͠ͱ • ϨΠϠߏ੒ • ΞϓϦέʔγϣϯ૚ • υϝΠϯ૚ • Πϯϑϥ૚ • બΜͩWAF/ORMͱͦͷഎܠ
40. ͳͥScala͔: ·ͱΊ • ৽ܾࡁγεςϜ͕ٻΊΔཁ݅Λຬͨͯ͘͠Εͦ͏ • ػೳੑ • อकੑ • ScalaΛॻ͘ΤϯδχΞΛҭͯΔ౔৕Λ੔͖͑ͯͨ • ScalaͷఆੴΛ୳ΔձɺڭՊॻ
41. ׬
42. DDDͷ࣮ફ
43. DDD͍ͨ͠ • υϝΠϯΤΩεύʔτͷ஌͕ࣝ
 ͦͷ··མͱ͠ࠐ·ΕͨαʔϏεʹ͍ͨ͠ • ཁૉٕज़ (Πϯϑϥ૚) ͱ෼཭Մೳʹ͍ͨ͠ • ࠷ѱ·ͨ࡞Γ௚͢͜ͱʹͳͬͯ΋
 ΑΓ௧ΈΛগͳ͍ͨ͘͠
44. ݱߦܾࡁγεςϜͷ൓ল • ํ਑͕పఈ͞Εͳ͔ͬͨ • ʮApp͸΋͏ͩΊͩɺServiceͰ΍Γͳ͓ͦ͏ʯ • ಺੡ͷPerl൛Active RecordతORM • ϞσϧɺαʔϏεɺϦϙδτϦ͕ᕒવҰମ • Perlͷݶք • ΠϯλʔϑΣʔε͕ͳ͍ • ΧϓηϧԽ͕ۃΊͯࠔ೉
45. ͸ͯͳϒοΫϚʔΫ in Scala
46. [PR]
 PerlͰ΋ΠέͯΔ։ൃ͍ͯ͠·͢ Perlͷ্ʹ΋ࡾ೥
 ʙͣͬͱΠέͯΔαʔϏεΛ࡞Γଓ͚Δٕज़ʙ http://yapcasia.org/2015/talk/show/de9e7a1e-136d-11e5-a9fc- d9f87d574c3a
47. DDD஥ؒ
48. ͸ͯͳࣾ಺Ͱ։࠵ͨ͠
 DDDษڧձͷ༷ࢠΛ͝঺հ͠·͢ http://developer.hatenastaff.com/entry/2015/08/20/170300
49. ΤϦοΫɾΤϰΝϯεͷ
 υϝΠϯۦಈઃܭ http://www.shoeisha.co.jp/book/detail/9784798126708
50. ࣮ફυϝΠϯۦಈઃܭ http://www.shoeisha.co.jp/book/detail/9784798131610
51. ࣾ಺DDDษڧձ
52. ࣾ಺DDDษڧձ • ਎ۙͳέʔεʹ͍ͭͯٞ࿦ • ৽͘͠࡞ΔͳΒɺ͍·͔Βվળ͢ΔͳΒ • ֎ͷੈքͷ஌ݟΛڞ༗ • ʮScalaͩͱ͜͏͍͏ػೳ͕͋ͬͯ……ʯ • ʮHaskellͩͱ……ʯ • ʮRubyͷ˓˓ͱ͍͏ϥΠϒϥϦ͸……ʯ
53. DDDͷ࣮ફͱ࡞ઓ
54. ೰Μͩͱ͜ΖɾݟͲ͜Ζ • ΤϯςΟςΟͷදݱ • ґଘੑͷ஫ೖ (DI) • cake pattern • αϒϓϩδΣΫτԽ • layering violationΛ๷͙
55. ΤϯςΟςΟͷදݱ
56. ΤϯςΟςΟͷදݱ • ΤϯςΟςΟ͸ૉ๿ͳcase class • ORM͸Slick • tarao/slick-jdbc-extensionΛ࢖ͬͯੜSQLͰҾ͍ͯ
 case class΁Ϛοϐϯά
57. ΤϯςΟςΟͷදݱ • ΤϯςΟςΟ = ID + υϝΠϯϞσϧ • ܕ΋ύϥϝʔλԽ͞Ε͍ͯΔ • υϝΠϯϞσϧʹରͯ͠ڞม • ಉ͡IDܕ͕ͩυϝΠϯϞσϧ͕ҟͳΔ
 ΤϯςΟςΟΛఆٛͰ͖Δ
58. ίʔυྫ case class EntityKey[ID]( val repr: String ) extends AnyVal abstract class Entity[K, +V]( val id: EntityKey[K], val value: V )(implicit ev: V <:< K)
59. ίʔυྫ case class EntityKey[ID]( val repr: String ) extends AnyVal abstract class Entity[K, +V]( val id: EntityKey[K], val value: V )(implicit ev: V <:< K) phantom type
60. ίʔυྫ case class EntityKey[ID]( val repr: String ) extends AnyVal abstract class Entity[K, +V]( val id: EntityKey[K], val value: V )(implicit ev: V <:< K) ஋ܕΛڞมʹ
61. ίʔυྫ case class EntityKey[ID]( val repr: String ) extends AnyVal abstract class Entity[K, +V]( val id: EntityKey[K], val value: V )(implicit ev: V <:< K) ஋ͷܕ͕IDͷܕͷαϒΫϥεͰ͋Δ
 ܕύϥϝʔλ੍໿
62. cake pattern
63. ΠϯλʔϑΣʔεΛఆٛ package repo trait AccountComponent { def accountLoader: AccountLoader trait AccountLoader }
64. ࣮૷ package infra.db trait AccountComponent extends repo.AccountComponent { def accountLoader: AccountLoader = AccountDB object AccountDB extends AccountLoader { ... } }
65. ґଘͷએݴͱ࢖༻ package app trait AccountApp { self: repo.AccountComponent => accountLoader.find(...) }
66. ґଘͷ஫ೖ package main object Root extends app.AccountApp with infra.db.AccountComponent
67. cake pattern • ίϯύΠϧλΠϜͰDI͞ΕΔ • Playͷίϯτϩʔϥ΋cake componentͱͯ͠߹੒
68. DDDͷ࣮ફ: ·ͱΊ • ࣾ಺ษڧձͰʰ࣮ફDDDʱΛྠಡɺ஌ݟΛڞ༗ • զʑʹͱͬͯͪΐ͏ͲΑ͍DDDΛݟ͚ͭΔ • ScalaͷྗΛ׆͔࣮ͨ͠૷ύλʔϯͷൃݟ
69. ׬
70. ·ͱΊ • ۜͷ஄ؙ͸ͳ͍! • ཁ݅ʹ͍͋ͬͯΔ͔ߟ͑Δ • ཁ݅ʹ͋ΘͤͯΞϨϯδ͍ͯ͘͠ • ʮͪΐ͏Ͳ͍͍DDDʯ • ʮͪΐ͏Ͳ͍͍ϚΠΫϩαʔϏεʯ • ࣌ʹ͸ࣃΛ৯͍͠͹Δ