$30 off During Our Annual Pro Sale. View Details »

Feral Concurrency Control: An Empirical Investigation of Modern Application Integrity

pbailis
June 03, 2015
Technology
5
1.5k

Feral Concurrency Control: An Empirical Investigation of Modern Application Integrity

SIGMOD 2015
3 June, Melbourne, Australia

Paper URL: http://www.bailis.org/papers/feral-sigmod2015.pdf

Abstract

The rise of data-intensive “Web 2.0” Internet services has led to a range of popular new programming frameworks that collectively embody the latest incarnation of the vision of Object-Relational Mapping (ORM) systems, albeit at unprecedented scale. In this work, we empirically investigate modern ORM-backed applications’ use and disuse of database concurrency control mechanisms. Specifically, we focus our study on the common use of feral, or application-level, mechanisms for maintaining database integrity, which, across a range of ORM systems, often take the form of declarative correctness criteria, or invariants. We quantitatively analyzethe use of these mechanisms in a range of open source applications written using the Ruby on Rails ORM and find that feral invariants are the most popular means of ensuring integrity (and, by usage, are over 37 times more popular than transactions). We evaluate which of these feral invariants actually ensure integrity (by usage, up to 86.9%) and which—due to concurrency errors and lack of database support—may lead to data corruption (the remainder), which we experimentally quantify. In light of these findings, we present recommendations for database system designers for better supporting these modern ORM programming patterns, thus eliminating their adverse effects on application integrity.

pbailis

June 03, 2015
Tweet

More Decks by pbailis

See All by pbailis
Papers We Love BOS: Streaming Queries over Streaming Data
pbailis
0
360
When Worst is Best in Distributed Systems Design
pbailis
5
690
Silence is Golden: Coordination-Avoiding Systems Design
pbailis
24
4.6k
The Case for Invariant-Based Concurrency Control
pbailis
6
680
Coordination Avoidance In Distributed Databases
pbailis
0
280
Papers We Love: Managing Update Conflicts in Bayou
pbailis
2
220
Highly Available Transactions: Virtues and Limitations
pbailis
2
710
Scalable Atomic Visibility with RAMP Transactions
pbailis
5
2.7k
Coordination and the Art of Scaling
pbailis
11
3.7k

Other Decks in Technology

See All in Technology
Honoが良さそう🔥
is_ryo
0
140
Making your Kubernetes-based log collection reliable & durable with Vector
palark
0
200
Podman with WebAssembly
utam0k
2
230
Self-RAG: Learning to Retrieve, Generate and Critique through Self-Reflections
peisuke
8
820
異なる思想で書かれたコードの統一に動く -Terraformの場合-
coconala_engineer
0
160
リアルで価値を発揮するデジタルプロダクトを開発する
aki_iinuma
0
810
イベント企画設計における「フロントエンド」な考え方とその魅力
kgsi
1
1.8k
Exploring Postgres VACUUM with the VACUUM Simulator
keiko713
5
540
技術コミュニティ参加のすすめ
minorun365
PRO
4
260
スタートアップにおける、チーム拡大を見据えたコンポーネント分割の取り組み
rynsuke
2
330
GraphQLクライアントの技術選定 2023冬
kazukihayase
6
2.5k
2023年版 デザインシステム 技術選定の勘所 - フロントエンドカンファレンス沖縄
takanorip
2
1.5k

Featured

See All Featured
Ruby is Unlike a Banana
tanoku
93
10k
Embracing the Ebb and Flow
colly
77
3.8k
Teambox: Starting and Learning
jrom
125
8.2k
Unsuck your backbone
ammeep
660
56k
How to Ace a Technical Interview
jacobian
272
22k
Visualizing Your Data: Incorporating Mongo into Loggly Infrastructure
mongodb
33
8.6k
Building Your Own Lightsaber
phodgson
97
5.4k
Navigating Team Friction
lara
177
13k
How to Create Impact in a Changing Tech Landscape [PerfNow 2023]
tammyeverts
0
240
Thoughts on Productivity
jonyablonski
55
3.5k
The Art of Programming - Codeland 2020
erikaheidi
39
12k
[Rails World 2023 - Day 1 Closing Keynote] - The Magic of Rails
eileencodes
1
870

Transcript

  1. FERAL!DPODVSSFODZ!DPOUSPM;!
    AN EMPIRICAL INVESTIGATION OF
    MODERN APPLICATION INTEGRITY
    PETER BAILIS, Alan Fekete, Mike Franklin, Ali Ghodsi, Joe Hellerstein, Ion Stoica
    UC Berkeley and University of Sydney
    SIGMOD 2015
    3 June, Melbourne, Australia

    View Slide

  2. How do application developers
    use concurrency control today?

    View Slide

  3. View Slide

  4. 1.) Adopted

    View Slide

  5. 1.) Adopted

    View Slide

  6. 2.) Idiomatic

    View Slide

  7. 2.) Idiomatic

    View Slide

  8. 2.) Idiomatic

    View Slide

  9. 2.) Idiomatic

    View Slide

  10. 3.) Opinionated

    View Slide

  11. “I don’t want my database to be
    clever! …Stored procedures and
    constraints [are] vile and reckless
    destroyers of coherence. No, Mr.
    Database, you can not have my
    business logic…you’ll have to pry
    [it] from my dead, cold object-
    oriented hands . . .”
    3.) Opinionated

    View Slide

  12. How do developers use
    concurrency control today?

    View Slide

  13. 1.) Adopted
    2.) Idiomatic
    3.) Opinionated
    How do developers use
    concurrency control today?

    View Slide

  14. For our purposes: application
    server in three-tier model

    View Slide

  15. For our purposes: application
    server in three-tier model
    Web
    Server

    View Slide

  16. For our purposes: application
    server in three-tier model
    Web
    Server
    DBMS

    View Slide

  17. For our purposes: application
    server in three-tier model
    Rails Rails Rails
    Web
    Server
    DBMS

    View Slide

  18. For our purposes: application
    server in three-tier model
    Rails Rails Rails
    Web
    Server
    DBMS

    View Slide

  19. For our purposes: application
    server in three-tier model
    Rails Rails Rails
    Web
    Server
    DBMS
    Requests processed
    concurrently

    View Slide

  20. For our purposes: application
    server in three-tier model
    Rails Rails Rails
    Web
    Server
    DBMS
    Requests processed
    concurrently
    So how do
    applications handle
    concurrency?

    View Slide

  21. View Slide

  22. adopt-a-hydrant
    alchemy_cms
    amahi
    bostonrb
    boxroom
    brevidy
    browsercms
    bucketwise
    calagator
    canvas-lms
    carter
    chiliproject
    citizenry
    comas
    comfortable-
    mexican-sofa
    communityengine
    copycopter-
    server
    danbooru
    diaspora
    discourse
    enki
    fat_free_crm
    fedena
    forem
    fulcrum
    gitlab-ci
    gitlabhq
    govsgo
    heaven
    inkwell
    insoshi
    jobsworth
    juvia
    kandan
    linuxfr.org
    lobsters
    lovd-by-less
    nimbleshop
    obtvse
    onebody
    opal
    opencongress
    opengovernment
    openproject
    piggybak
    publify
    radiant
    railscollab
    redmine
    refinerycms
    ror_ecommerce
    rucksack
    saasy
    salor-retail
    selfstarter
    sharetribe
    skyline
    spot-us
    spree
    sprintapp
    squaresquash
    sugar
    teambox
    tracks
    tryshoppe
    wallgig

    View Slide

  23. adopt-a-hydrant
    alchemy_cms
    amahi
    bostonrb
    boxroom
    brevidy
    browsercms
    bucketwise
    calagator
    canvas-lms
    carter
    chiliproject
    citizenry
    comas
    comfortable-mexican-sofa
    communityengine
    copycopter-server
    danbooru
    diaspora
    discourse
    enki
    fat_free_crm
    fedena
    forem
    fulcrum
    gitlab-ci
    gitlabhq
    govsgo
    heaven
    inkwell
    insoshi
    jobsworth
    juvia
    kandan
    linuxfr.org
    lobsters
    lovd-by-less
    nimbleshop
    obtvse
    onebody
    opal
    opencongress
    opengovernment
    openproject
    piggybak
    publify
    radiant
    railscollab
    redmine
    refinerycms
    ror_ecommerce
    rucksack
    saasy
    salor-retail
    selfstarter
    sharetribe
    skyline
    spot-us
    spree
    sprintapp
    squaresquash
    sugar
    teambox
    tracks
    tryshoppe
    wallgig
    zena
    67 projects 1.77M LoC 1957 tables

    View Slide

  24. adopt-a-hydrant
    alchemy_cms
    amahi
    bostonrb
    boxroom
    brevidy
    browsercms
    bucketwise
    calagator
    canvas-lms
    carter
    chiliproject
    citizenry
    comas
    comfortable-mexican-sofa
    communityengine
    copycopter-server
    danbooru
    diaspora
    discourse
    enki
    fat_free_crm
    fedena
    forem
    fulcrum
    gitlab-ci
    gitlabhq
    govsgo
    heaven
    inkwell
    insoshi
    jobsworth
    juvia
    kandan
    linuxfr.org
    lobsters
    lovd-by-less
    nimbleshop
    obtvse
    onebody
    opal
    opencongress
    opengovernment
    openproject
    piggybak
    publify
    radiant
    railscollab
    redmine
    refinerycms
    ror_ecommerce
    rucksack
    saasy
    salor-retail
    selfstarter
    sharetribe
    skyline
    spot-us
    spree
    sprintapp
    squaresquash
    sugar
    teambox
    tracks
    tryshoppe
    wallgig
    zena
    67 projects 1.77M LoC 1957 tables
    259 total; avg. 0.13 per table

    View Slide

  25. adopt-a-hydrant
    alchemy_cms
    amahi
    bostonrb
    boxroom
    brevidy
    browsercms
    bucketwise
    calagator
    canvas-lms
    carter
    chiliproject
    citizenry
    comas
    comfortable-mexican-sofa
    communityengine
    copycopter-server
    danbooru
    diaspora
    discourse
    enki
    fat_free_crm
    fedena
    forem
    fulcrum
    gitlab-ci
    gitlabhq
    govsgo
    heaven
    inkwell
    insoshi
    jobsworth
    juvia
    kandan
    linuxfr.org
    lobsters
    lovd-by-less
    nimbleshop
    obtvse
    onebody
    opal
    opencongress
    opengovernment
    openproject
    piggybak
    publify
    radiant
    railscollab
    redmine
    refinerycms
    ror_ecommerce
    rucksack
    saasy
    salor-retail
    selfstarter
    sharetribe
    skyline
    spot-us
    spree
    sprintapp
    squaresquash
    sugar
    teambox
    tracks
    tryshoppe
    wallgig
    zena
    67 projects 1.77M LoC 1957 tables
    259 total; avg. 0.13 per table
    Transactions
    are not popular!

    View Slide

  26. adopt-a-hydrant
    alchemy_cms
    amahi
    bostonrb
    boxroom
    brevidy
    browsercms
    bucketwise
    calagator
    canvas-lms
    carter
    chiliproject
    citizenry
    comas
    comfortable-mexican-sofa
    communityengine
    copycopter-server
    danbooru
    diaspora
    discourse
    enki
    fat_free_crm
    fedena
    forem
    fulcrum
    gitlab-ci
    gitlabhq
    govsgo
    heaven
    inkwell
    insoshi
    jobsworth
    juvia
    kandan
    linuxfr.org
    lobsters
    lovd-by-less
    nimbleshop
    obtvse
    onebody
    opal
    opencongress
    opengovernment
    openproject
    piggybak
    publify
    radiant
    railscollab
    redmine
    refinerycms
    ror_ecommerce
    rucksack
    saasy
    salor-retail
    selfstarter
    sharetribe
    skyline
    spot-us
    spree
    sprintapp
    squaresquash
    sugar
    teambox
    tracks
    tryshoppe
    wallgig
    zena
    67 projects 1.77M LoC 1957 tables
    259 total; avg. 0.13 per table
    Transactions
    are not popular!
    So how do apps ensure
    integrity?

    View Slide

  27. Rails Integrity Mechanisms

    View Slide

  28. 1.) Transactions: in business logic
    Rails Integrity Mechanisms

    View Slide

  29. 1.) Transactions: in business logic
    2.) Validations: invariants on schema
    Rails Integrity Mechanisms

    View Slide

  30. 1.) Transactions: in business logic
    2.) Validations: invariants on schema
    class Person < ActiveRecord::Base
    validates :name, presence: true, uniqueness: true
    end
    Rails Integrity Mechanisms

    View Slide

  31. 3.) Associations: relational integrity
    1.) Transactions: in business logic
    2.) Validations: invariants on schema
    class Person < ActiveRecord::Base
    validates :name, presence: true, uniqueness: true
    end
    Rails Integrity Mechanisms

    View Slide

  32. 3.) Associations: relational integrity
    1.) Transactions: in business logic
    2.) Validations: invariants on schema
    class Person < ActiveRecord::Base
    validates :name, presence: true, uniqueness: true
    end
    class Order < ActiveRecord::Base
    belongs_to :customer
    end
    Rails Integrity Mechanisms

    View Slide

  33. adopt-a-hydrant
    alchemy_cms
    amahi
    bostonrb
    boxroom
    brevidy
    browsercms
    bucketwise
    calagator
    canvas-lms
    carter
    chiliproject
    citizenry
    comas
    comfortable-mexican-sofa
    communityengine
    copycopter-server
    danbooru
    diaspora
    discourse
    enki
    fat_free_crm
    fedena
    forem
    fulcrum
    gitlab-ci
    gitlabhq
    govsgo
    heaven
    inkwell
    insoshi
    jobsworth
    juvia
    kandan
    linuxfr.org
    lobsters
    lovd-by-less
    nimbleshop
    obtvse
    onebody
    opal
    opencongress
    opengovernment
    openproject
    piggybak
    publify
    radiant
    railscollab
    redmine
    refinerycms
    ror_ecommerce
    rucksack
    saasy
    salor-retail
    selfstarter
    sharetribe
    skyline
    spot-us
    spree
    sprintapp
    squaresquash
    sugar
    teambox
    tracks
    tryshoppe
    wallgig
    zena
    67 projects 1.77M LoC 1957 tables
    259 total; avg. 0.13 per table

    View Slide

  34. adopt-a-hydrant
    alchemy_cms
    amahi
    bostonrb
    boxroom
    brevidy
    browsercms
    bucketwise
    calagator
    canvas-lms
    carter
    chiliproject
    citizenry
    comas
    comfortable-mexican-sofa
    communityengine
    copycopter-server
    danbooru
    diaspora
    discourse
    enki
    fat_free_crm
    fedena
    forem
    fulcrum
    gitlab-ci
    gitlabhq
    govsgo
    heaven
    inkwell
    insoshi
    jobsworth
    juvia
    kandan
    linuxfr.org
    lobsters
    lovd-by-less
    nimbleshop
    obtvse
    onebody
    opal
    opencongress
    opengovernment
    openproject
    piggybak
    publify
    radiant
    railscollab
    redmine
    refinerycms
    ror_ecommerce
    rucksack
    saasy
    salor-retail
    selfstarter
    sharetribe
    skyline
    spot-us
    spree
    sprintapp
    squaresquash
    sugar
    teambox
    tracks
    tryshoppe
    wallgig
    zena
    67 projects 1.77M LoC 1957 tables
    9986 total; avg. 5.1 per table
    259 total; avg. 0.13 per table

    View Slide

  35. ALTERNATIVES
    MORE COMMON
    37x
    adopt-a-hydrant
    alchemy_cms
    amahi
    bostonrb
    boxroom
    brevidy
    browsercms
    bucketwise
    calagator
    canvas-lms
    carter
    chiliproject
    citizenry
    comas
    comfortable-mexican-sofa
    communityengine
    copycopter-server
    danbooru
    diaspora
    discourse
    enki
    fat_free_crm
    fedena
    forem
    fulcrum
    gitlab-ci
    gitlabhq
    govsgo
    heaven
    inkwell
    insoshi
    jobsworth
    juvia
    kandan
    linuxfr.org
    lobsters
    lovd-by-less
    nimbleshop
    obtvse
    onebody
    opal
    opencongress
    opengovernment
    openproject
    piggybak
    publify
    radiant
    railscollab
    redmine
    refinerycms
    ror_ecommerce
    rucksack
    saasy
    salor-retail
    selfstarter
    sharetribe
    skyline
    spot-us
    spree
    sprintapp
    squaresquash
    sugar
    teambox
    tracks
    tryshoppe
    wallgig
    zena
    67 projects 1.77M LoC 1957 tables
    9986 total; avg. 5.1 per table
    259 total; avg. 0.13 per table

    View Slide

  36. ALTERNATIVES
    MORE COMMON
    37x
    adopt-a-hydrant
    alchemy_cms
    amahi
    bostonrb
    boxroom
    brevidy
    browsercms
    bucketwise
    calagator
    canvas-lms
    carter
    chiliproject
    citizenry
    comas
    comfortable-mexican-sofa
    communityengine
    copycopter-server
    danbooru
    diaspora
    discourse
    enki
    fat_free_crm
    fedena
    forem
    fulcrum
    gitlab-ci
    gitlabhq
    govsgo
    heaven
    inkwell
    insoshi
    jobsworth
    juvia
    kandan
    linuxfr.org
    lobsters
    lovd-by-less
    nimbleshop
    obtvse
    onebody
    opal
    opencongress
    opengovernment
    openproject
    piggybak
    publify
    radiant
    railscollab
    redmine
    refinerycms
    ror_ecommerce
    rucksack
    saasy
    salor-retail
    selfstarter
    sharetribe
    skyline
    spot-us
    spree
    sprintapp
    squaresquash
    sugar
    teambox
    tracks
    tryshoppe
    wallgig
    zena
    67 projects 1.77M LoC 1957 tables
    9986 total; avg. 5.1 per table
    259 total; avg. 0.13 per table
    WHY?

    View Slide

  37. View Slide

  38. IT’S ALL
    ABOUT
    IDIOMS!

    View Slide

  39. Validations
    and
    associations
    are
    core
    Rails
    concepts
    IT’S ALL
    ABOUT
    IDIOMS!

    View Slide

  40. Validations
    and
    associations
    are
    core
    Rails
    concepts
    IT’S ALL
    ABOUT
    IDIOMS!

    View Slide

  41. Validations
    and
    associations
    are
    core
    Rails
    concepts
    IT’S ALL
    ABOUT
    IDIOMS!

    View Slide

  42. 3.) Associations: relational integrity
    1.) Transactions: in business logic
    2.) Validations: invariants on schema
    class Person < ActiveRecord::Base
    validates :name, presence: true, uniqueness: true
    end
    class Order < ActiveRecord::Base
    belongs_to :customer
    end
    Rails Integrity Mechanisms

    View Slide

  43. 3.) Associations: relational integrity
    2.) Validations: invariants on schema

    View Slide

  44. 3.) Associations: relational integrity
    2.) Validations: invariants on schema

    View Slide

  45. ARE
    - OPAQUE TO DBMS
    3.) Associations: relational integrity
    2.) Validations: invariants on schema

    View Slide

  46. ARE
    - OPAQUE TO DBMS
    - IMPLEMENTED IN RAILS LOGIC
    3.) Associations: relational integrity
    2.) Validations: invariants on schema

    View Slide

  47. ARE
    - OPAQUE TO DBMS
    - IMPLEMENTED IN RAILS LOGIC
    FERAL CONCURRENCY CONTROL
    3.) Associations: relational integrity
    2.) Validations: invariants on schema

    View Slide

  48. Rails developers
    prefer feral mechanisms

    View Slide

  49. Rails developers
    prefer feral mechanisms
    Do they work?

    View Slide

  50. Rails developers
    prefer feral mechanisms
    Do they work?
    What does this mean for databases?

    View Slide

  51. Rails developers
    prefer feral mechanisms
    Do they work?
    What does this mean for databases?

    View Slide

  52. Rails Execution Model
    Requests processed
    concurrently
    Rails Rails Rails
    Web
    Server
    DBMS

    View Slide

  53. Rails Execution Model
    Requests processed
    concurrently
    Rails Rails Rails
    Web
    Server
    DBMS

    View Slide

  54. Rails Execution Model
    Requests processed
    concurrently
    Validations run
    concurrently!
    Rails Rails Rails
    Web
    Server
    DBMS

    View Slide

  55. Rails Execution Model
    Requests processed
    concurrently
    Validations run
    concurrently!
    CAN’T WE USE TXNS?
    Rails Rails Rails
    Web
    Server
    DBMS

    View Slide

  56. Rails Execution Model
    Requests processed
    concurrently
    Validations run
    concurrently!
    CAN’T WE USE TXNS?
    Rails Rails Rails
    Web
    Server
    DBMS
    INSUFFICIENT
    DUE TO WEAK ISOLATION

    View Slide

  57. How can we tell if a given
    validation will enforce integrity
    under concurrent execution?

    View Slide

  58. Key idea: Check if validations can be violated by
    “merging” independent operations
    ICT: Invariant Confluence Test
    [VLDB 2015]
    How can we tell if a given
    validation will enforce integrity
    under concurrent execution?

    View Slide

  59. Key idea: Check if validations can be violated by
    “merging” independent operations
    ICT: Invariant Confluence Test
    [VLDB 2015]

    View Slide

  60. VALIDATION: User IDs are unique
    OPERATION: Save new user
    MERGE: Add both records to DB
    Key idea: Check if validations can be violated by
    “merging” independent operations
    ICT: Invariant Confluence Test
    [VLDB 2015]

    View Slide

  61. VALIDATION: User IDs are unique
    OPERATION: Save new user
    MERGE: Add both records to DB
    {{Stu,ID=1},
    {Jan,ID=1}}
    Validation
    fails!
    {}
    MERGE
    add
    {Stu,ID=1}
    add
    {Ann,ID=1}
    Key idea: Check if validations can be violated by
    “merging” independent operations
    ICT: Invariant Confluence Test
    [VLDB 2015]

    View Slide

  62. Key idea: Check if validations can be violated by
    “merging” independent operations
    VALIDATION: User IDs are positive
    OPERATION: Save new user
    MERGE: Add both records to DB
    ICT: Invariant Confluence Test
    [VLDB 2015]

    View Slide

  63. Key idea: Check if validations can be violated by
    “merging” independent operations
    VALIDATION: User IDs are positive
    OPERATION: Save new user
    MERGE: Add both records to DB
    {{Stu,ID=1},
    {Jan,ID=1}}
    Validation
    holds!
    {}
    MERGE
    add
    {Stu,ID=1}
    add
    {Ann,ID=1}
    ICT: Invariant Confluence Test
    [VLDB 2015]

    View Slide

  64. adopt-a-hydrant
    alchemy_cms
    amahi
    bostonrb
    boxroom
    brevidy
    browsercms
    bucketwise
    calagator
    canvas-lms
    carter
    chiliproject
    citizenry
    comas
    comfortable-mexican-sofa
    communityengine
    copycopter-server
    danbooru
    diaspora
    discourse
    enki
    fat_free_crm
    fedena
    forem
    fulcrum
    gitlab-ci
    gitlabhq
    govsgo
    heaven
    inkwell
    insoshi
    jobsworth
    juvia
    kandan
    linuxfr.org
    lobsters
    lovd-by-less
    nimbleshop
    obtvse
    onebody
    opal
    opencongress
    opengovernment
    openproject
    piggybak
    publify
    radiant
    railscollab
    redmine
    refinerycms
    ror_ecommerce
    rucksack
    saasy
    salor-retail
    selfstarter
    sharetribe
    skyline
    spot-us
    spree
    sprintapp
    squaresquash
    sugar
    teambox
    tracks
    tryshoppe
    wallgig
    zena
    67 projects 1.77M LoC 1957 tables
    9986 total; avg. 5.1 per table
    259 total; avg. 0.13 per table

    View Slide

  65. adopt-a-hydrant
    alchemy_cms
    amahi
    bostonrb
    boxroom
    brevidy
    browsercms
    bucketwise
    calagator
    canvas-lms
    carter
    chiliproject
    citizenry
    comas
    comfortable-mexican-sofa
    communityengine
    copycopter-server
    danbooru
    diaspora
    discourse
    enki
    fat_free_crm
    fedena
    forem
    fulcrum
    gitlab-ci
    gitlabhq
    govsgo
    heaven
    inkwell
    insoshi
    jobsworth
    juvia
    kandan
    linuxfr.org
    lobsters
    lovd-by-less
    nimbleshop
    obtvse
    onebody
    opal
    opencongress
    opengovernment
    openproject
    piggybak
    publify
    radiant
    railscollab
    redmine
    refinerycms
    ror_ecommerce
    rucksack
    saasy
    salor-retail
    selfstarter
    sharetribe
    skyline
    spot-us
    spree
    sprintapp
    squaresquash
    sugar
    teambox
    tracks
    tryshoppe
    wallgig
    zena
    67 projects 1.77M LoC 1957 tables
    9986 total; avg. 5.1 per table
    259 total; avg. 0.13 per table
    86.9% PASS ICT

    View Slide

  66. Do they work?
    Rails developers
    prefer feral mechanisms

    View Slide

  67. Do they work?
    Rails developers
    prefer feral mechanisms
    86.9% PASS ICT

    View Slide

  68. Do they work?
    Rails developers
    prefer feral mechanisms
    Yes, safe!
    86.9% PASS ICT

    View Slide

  69. Do they work?
    Rails developers
    prefer feral mechanisms
    Yes, safe!
    86.9% PASS ICT
    13.1% FAIL ICT

    View Slide

  70. Do they work?
    Rails developers
    prefer feral mechanisms
    Yes, safe!
    86.9% PASS ICT
    13.1% FAIL ICT No, unsafe!

    View Slide

  71. Do they work?
    Rails developers
    prefer feral mechanisms
    Yes, safe!
    86.9% PASS ICT
    13.1% FAIL ICT No, unsafe!
    How bad are these 13.1%?

    View Slide

  72. Uniqueness validation is broken

    View Slide

  73. Uniqueness validation is broken
    FAILS ICT

    View Slide

  74. 1 2 4 8 16 32 64
    Number of Rails Processes
    0
    100
    101
    102
    103
    104
    Number of Duplicate Records
    Without validation
    With validation
    Uniqueness validation is broken
    FAILS ICT

    View Slide

  75. 1 2 4 8 16 32 64
    Number of Rails Processes
    0
    100
    101
    102
    103
    104
    Number of Duplicate Records
    Without validation
    With validation
    Uniqueness validation is broken
    FAILS ICT

    View Slide

  76. 1 2 4 8 16 32 64
    Number of Rails Processes
    0
    100
    101
    102
    103
    104
    Number of Duplicate Records
    Without validation
    With validation
    Uniqueness validation is broken
    FAILS ICT

    View Slide

  77. 1 2 4 8 16 32 64
    Number of Rails Processes
    0
    100
    101
    102
    103
    104
    Number of Duplicate Records
    Without validation
    With validation
    Uniqueness validation is broken
    FAILS ICT

    View Slide

  78. Association validation is broken

    View Slide

  79. 1 2 4 8 16 32 64
    Number of Rails Workers
    0
    100
    101
    102
    103
    104
    Number of Orphaned Users
    Without validation
    With validation
    Association validation is broken

    View Slide

  80. 1 2 4 8 16 32 64
    Number of Rails Workers
    0
    100
    101
    102
    103
    104
    Number of Orphaned Users
    Without validation
    With validation
    Association validation is broken
    FAILS ICT

    View Slide

  81. 1 2 4 8 16 32 64
    Number of Rails Workers
    0
    100
    101
    102
    103
    104
    Number of Orphaned Users
    Without validation
    With validation
    Association validation is broken
    FAILS ICT

    View Slide

  82. 1 2 4 8 16 32 64
    Number of Rails Workers
    0
    100
    101
    102
    103
    104
    Number of Orphaned Users
    Without validation
    With validation
    Association validation is broken
    FAILS ICT

    View Slide

  83. 1 2 4 8 16 32 64
    Number of Rails Workers
    0
    100
    101
    102
    103
    104
    Number of Orphaned Users
    Without validation
    With validation
    Association validation is broken
    FAILS ICT

    View Slide

  84. Takeaway: Rails’s feral validations,
    though popular, do not guarantee integrity!

    View Slide

  85. Takeaway: Rails’s feral validations,
    though popular, do not guarantee integrity!
    Not just Rails!
    ORM Supports Feral Validation?
    Java Persistence API Yes
    Hibernate (Java) Yes
    CakePHP Yes
    Laravel (PHP) Yes
    Django (Python) Yes
    Waterline (node.js) Yes

    View Slide

  86. Databases are providing
    the wrong abstractions:

    View Slide

  87. Databases are providing
    the wrong abstractions:
    1.) DBs should allow apps to express validations
    natively, while enforcing them correctly

    View Slide

  88. Databases are providing
    the wrong abstractions:
    1.) DBs should allow apps to express validations
    natively, while enforcing them correctly
    2.) Apps should pay the price of coordination
    only when strictly necessary (13.1% of time)

    View Slide

  89. Databases are providing
    the wrong abstractions:
    1.) DBs should allow apps to express validations
    natively, while enforcing them correctly
    2.) Apps should pay the price of coordination
    only when strictly necessary (13.1% of time)
    3.) DBs should facilitate portable
    deployment of applications

    View Slide

  90. Databases are providing
    the wrong abstractions:
    1.) DBs should allow apps to express validations
    natively, while enforcing them correctly
    2.) Apps should pay the price of coordination
    only when strictly necessary (13.1% of time)
    3.) DBs should facilitate portable
    deployment of applications
    RESEARCH GOLDMINE
    USERS
    CARE!
    +

    View Slide

  91. How do application developers
    use concurrency control today?

    View Slide

  92. A broader opportunity

    View Slide

  93. A broader opportunity
    How are our abstractions performing?

    View Slide

  94. A broader opportunity
    How are our abstractions performing?
    Do people like using transactions?
    Do people like using the relational model?
    Do people like using XML?

    View Slide

  95. A broader opportunity
    How are our abstractions performing?
    Open source provides a quantitative lens!
    Do people like using transactions?
    Do people like using the relational model?
    Do people like using XML?

    View Slide

  96. Open source provides a quantitative lens!

    View Slide

  97. Open source provides a quantitative lens!
    0.0 0.2 0.4 0.6 0.8 1.0
    0.0
    0.2
    0.4
    0.6
    0.8
    1.0
    Commits Authored (CDF)
    0.0 0.2 0.4 0.6 0.8 1.0
    Proportion Authors
    0.0
    0.2
    0.4
    0.6
    0.8
    1.0
    Valid/Assoc Authored (CDF)
    Asking
    creative
    questions
    is
    the hardest
    part!

    View Slide

  98. Conclusions
    • Feral validations are surprisingly common in many
    modern open source web applications
    • By usage, many validations are safe, but a substantial
    fraction are not and may allow data corruption
    • Providing proper RDBMS support for these validations is
    a pressing research challenge for the community
    • Open source is an exciting, untapped resource; be bold!

    View Slide