Ruby Can Too Scale: Highly Performant Microservices in Ruby (OSCON 2016)

Ruby developers have known for years that our beloved language is one of the most joyful to use. And yet, “Ruby Can’t Scale” seems to be a daily article on Hacker News. Tim Krajcar presents some tips and tricks that he’s learned at New Relic writing Ruby services that scale to hundreds of thousands of requests per minute.

Topics include:

* Building performance into your architecture from your first commit
* Where to invest precious development hours to realize the most performance value
* Which frameworks to use, and which to avoid, when working at scale
* Designing to avoid cascading failures when building highly interdependent services

Transcript

1. Ruby Can Too Scale: Highly Performant Microservices in Ruby Tim Krajcar
2. April 2015
3. TimKrajcar \
4. TimKrajcar This document and the information herein (including any information that may be incorporated by reference) is provided for informational purposes only and should not be construed as an offer, commitment, promise or obligation on behalf of New Relic, Inc. (“New Relic”) to sell securities or deliver any product, material, code, functionality, or other feature. Any information provided hereby is proprietary to New Relic and may not be replicated or disclosed without New Relic’s express written permission. Such information may contain forward-looking statements within the meaning of federal securities laws. Any statement that is not a historical fact or refers to expectations, projections, future plans, objectives, estimates, goals, or other characterizations of future events is a forward-looking statement. These forward-looking statements can often be identified as such because the context of the statement will include words such as “believes,” “anticipates,” “expects” or words of similar import. Actual results may differ materially from those expressed in these forward-looking statements, which speak only as of the date hereof, and are subject to change at any time without notice. Existing and prospective investors, customers and other third parties transacting business with New Relic are cautioned not to place undue reliance on this forward-looking information. The achievement or success of the matters covered by such forward-looking statements are based on New Relic’s current assumptions, expectations, and beliefs and are subject to substantial risks, uncertainties, assumptions, and changes in circumstances that may cause the actual results, performance, or achievements to differ materially from those expressed or implied in any forward-looking statement. Further information on factors that could affect such forward-looking statements is included in the filings we make with the SEC from time to time. Copies of these documents may be obtained by visiting New Relic’s Investor Relations website at ir.newrelic.com or the SEC’s website at www.sec.gov. New Relic assumes no obligation and does not intend to update these forward-looking statements, except as required by law. New Relic makes no warranties, expressed or implied, in this document or otherwise, with respect to the information provided.
5. TimKrajcar
6. TimKrajcar why this talk?
11. TimKrajcar "ruby can't scale"
12. –Johnny Appleseed
13. –Johnny Appleseed
14. –Johnny Appleseed
15. TimKrajcar "ruby can't scale"
16. TimKrajcar "rails can't scale"
17. TimKrajcar second system effect
18. –Johnny Appleseed
19. –Johnny Appleseed and, even more importantly, stack
20. TimKrajcar why ruby?
21. TimKrajcar expressive programming language = fun to write code = I want to write more of it
22. TimKrajcar expressive programming language = fun to write code = I want to write more of it productivity!!
23. TimKrajcar things not covered
24. TimKrajcar 1. database tuning
25. TimKrajcar 1. database tuning 2. caching
26. TimKrajcar 1. database tuning 2. caching 3. network optimization
27. TimKrajcar 1. database tuning 2. caching 3. network optimization 4. browser-y things
28. TimKrajcar microservices at New Relic
29. TimKrajcar ~60 total services
30. TimKrajcar some not so micro
31. TimKrajcar Ruby: common for prototypes
32. TimKrajcar templates and auto- generation
33. –Johnny Appleseed
34. TimKrajcar stereotypical example: customer permissions service
35. –Johnny Appleseed
36. –Johnny Appleseed
37. PERFORMANCE FROM THE FIRST COMMIT
38. –Johnny Appleseed Structured programming with 'go to' statements Donald E. Knuth COMPUTING SURVEYS, DECEMBER 1974
39. –Johnny Appleseed We should forget about small efficiencies, say about 97% of the time: premature optimization is the root of all evil.
40. –Johnny Appleseed Yet we should not pass up our opportunities in that critical 3%. A good programmer will not be lulled into complacency by such reasoning, [and] will be wise to look carefully at the critical code.
41. TimKrajcar benchmarking methodologies matter
42. TimKrajcar app server time vs request queuing
43. –Johnny Appleseed
44. –Johnny Appleseed
45. TimKrajcar X-Request-Start HTTP header
46. TimKrajcar test suite tools
47. TimKrajcar minitest-perf https://github.com/mrsimo/minitest-perf
48. > bundle exec minitest-perf Slowest individual tests 1210.00ms | NewRelic::Agent::AgentTest#test_after_fork_should_ 1190.78ms | LicenseTest#test_for_scary_license_terms 1034.58ms | NewRelic::Agent::Agent::ConnectTest#test_connect_g 1034.20ms | NewRelic::Agent::Agent::ConnectTest#test_logging_c 1032.60ms | NewRelic::Agent::Agent::ConnectTest#test_environme 1031.61ms | NewRelic::Agent::Agent::ConnectTest#test_connect_s 1030.49ms | NewRelic::Agent::Agent::ConnectTest#test_connect_s 730.88ms | OrphanedConfigTest#test_all_default_source_config_ 455.05ms | NewRelic::Agent::MetricStatsTest#test_record_scope 434.18ms | NewRelicServiceTest#test_json_marshaller_should_ha
49. Slowest test suites 638.87ms | 2 | LicenseTest 293.86ms | 3 | OrphanedConfigTest 193.41ms | 27 | NewRelic::Agent::Agent::ConnectTest 191.36ms | 1 | NewRelic::Agent::Threading::BacktraceServic 130.64ms | 14 | NewRelic::Agent::PipeChannelManagerTest 118.76ms | 14 | PipeServiceTest 111.14ms | 4 | DispatcherTest 32.82ms | 63 | NewRelic::Agent::AgentTest 25.50ms | 20 | NewRelic::Agent::MetricStatsTest 19.37ms | 12 | NewRelic::Agent::UtilizationDataTest
50. TimKrajcar framework choices
51. TimKrajcar framework choices reductions
52. –Johnny Appleseed
53. TimKrajcar example!!
54. TimKrajcar a typical Ruby microservice: REST DB-to-JSON API https://github.com/tkrajcar/ruby-can-too-scale
55. TimKrajcar a typical Ruby microservice: REST DB-to-JSON API https://github.com/tkrajcar/ruby-can-too-scale !! warning: YOLOCODE !!
56. TimKrajcar •Rails 4.2.6 straight outta rails new + Puma + nginx •JSON only, using scaffolded controller & model •testing #index (~25kb) and #show (<1 kb) •read-only •Dedicated EC2 c3.large instances (2 vCPUs) •Postgres on its own dedicated RDS instance •30 users as fast as possible (separate instance)
57. TimKrajcar best metric: client requests per minute
58. TimKrajcar #index /articles.json #show /articles/1.json Stock Rails scaffolding 4,211 18,011
59. TimKrajcar #index /articles.json #show /articles/1.json Stock Rails scaffolding 4,211 18,011 No jbuilder templates 4,561 +8.3% 18,909 +4.9%
60. TimKrajcar #index /articles.json #show /articles/1.json Stock Rails scaffolding 4,211 18,011 No jbuilder templates 4,561 +8.3% 18,909 +4.9% oj gem 5,548 +21.6% 19,714 +9.4%
61. TimKrajcar #index /articles.json #show /articles/1.json Stock Rails scaffolding 4,211 18,011 No jbuilder templates 4,561 +8.3% 18,909 +4.9% oj gem 5,548 +21.6% 19,714 +9.4% Sequel instead of ActiveRecord 7,035 +26.8% 22,378 +13.5%
62. TimKrajcar #index /articles.json #show /articles/1.json Stock Rails scaffolding 4,211 18,011 No jbuilder templates 4,561 +8.3% 18,909 +4.9% oj gem 5,548 +21.6% 19,714 +9.4% Sequel instead of ActiveRecord 7,035 +26.8% 22,378 +13.5% Sinatra (with Sequel and oj) 13,245 85,017
63. TimKrajcar #index /articles.json #show /articles/1.json Stock Rails scaffolding 4,211 18,011 No jbuilder templates 4,561 +8.3% 18,909 +4.9% oj gem 5,548 +21.6% 19,714 +9.4% Sequel instead of ActiveRecord 7,035 +26.8% 22,378 +13.5% Sinatra (with Sequel and oj) 13,245 85,017
64. TimKrajcar tl;dr: use Sinatra and Sequel
65. DIVING DEEPER
66. TimKrajcar Derailed Benchmarks https://github.com/schneems/derailed_benchmarks
67. > bundle exec derailed bundle:mem TOP: 46.5625 MiB activeadmin: 17.5156 MiB active_admin: 17.5039 MiB meta_search: 6.2773 MiB meta_search/searches/active_record: 1.707 MiB meta_search/builder: 1.5938 MiB meta_search/where: 1.0977 MiB polyamorous: 0.4688 MiB active_admin/comments: 3.6055 MiB active_admin/comments/views: 1.375 MiB active_admin/views: 1.2305 MiB (Also required by: active_admin/comments/views/active_admin_comments) /Users/tkrajcar/.rbenv/versions/2.1.7/lib/ruby/gems/ 2.1.0/gems/activeadmin-0.6.3/lib/active_admin/views/components/ paginated_collection.rb: 0.3125 MiB bourbon: 3.3438 MiB
68. > bundle exec derailed bundle:objects Measuring objects created by gems in groups [:default, "production"] Total allocated: 72414462 bytes (425465 objects) Total retained: 24736698 bytes (44790 objects) allocated memory by gem ----------------------------------- 27407703 activesupport-3.2.22.2 9240545 erubis-2.7.0 5722758 actionpack-3.2.22.2 3287857 activerecord-3.2.22.2 3176375 haml-4.0.5 1728840 meta_search-1.1.3 1300638 devise-1.5.4 1216006 2.1.7/lib 1016914 formtastic-2.2.1 993225 activeadmin-0.6.3
69. TimKrajcar Stackprof https://github.com/tmm1/stackprof
70. –Johnny Appleseed
71. TimKrajcar other interpreters
72. DESIGNING TO AVOID CASCADING FAILURES
73. TimKrajcar timeouts
74. –Johnny Appleseed
76. TimKrajcar Timeout
77. require 'timeout' result = begin Timeout::timeout(0.5) { do_a_possibly_slow_thing } rescue Timeout::Error # log/notify about the timeout 0 end
81. TimKrajcar circuit breaker pattern
82. –Johnny Appleseed http://martinfowler.com/bliki/CircuitBreaker.html
83. TimKrajcar cb2 https://github.com/pedro/cb2
84. require 'cb2' breaker = CB2::Breaker.new( service: "cashwings", # identify each circuit breaker individually duration: 60, # in this amount of seconds... threshold: 5, # ...this % of errors will open the breaker reenable_after: 600, # once opened, how long until we try again redis: Redis.new) # uses Redis to keep track by service name
85. require 'cb2' breaker = CB2::Breaker.new( service: "cashwings", # identify each circuit breaker individually duration: 60, # in this amount of seconds... threshold: 5, # ...this % of errors will open the breaker reenable_after: 600, # once opened, how long until we try again redis: Redis.new) # uses Redis to keep track by service name
86. begin breaker.run do some_api_request() end rescue CB2::BreakerOpen # log/notify about the breaker opening! alternate_response() end
87. TimKrajcar parallelize
88. TimKrajcar parallelize everything especially HTTP
89. TimKrajcar Typhoeus::Hydra https://github.com/typhoeus/typhoeus
90. require 'typhoeus' request1 = Typhoeus::Request.new("http://example.com/1.json") request2 = Typhoeus::Request.new("http://example.com/2.json") hydra = Typhoeus::Hydra.new hydra.queue(request1) hydra.queue(request2) hydra.run # blocks here until queue finishes puts "Request 1 status #{request1.response.code}" puts "Request 2 status #{request2.response.code}"
91. TimKrajcar background everything* *unless you can't
92. TimKrajcar https://github.com/mperham/sidekiq
93. # app/workers/welcome_emailer.rb class WelcomeEmailer include Sidekiq::Worker def perform(email) send_email_to(email, "Welcome!") end end # app/controllers/welcome_controller.rb def welcome # blah blah create a @user WelcomeEmailer.perform_async(@user.email) end
94. # app/workers/welcome_emailer.rb class WelcomeEmailer include Sidekiq::Worker def perform(email) send_email_to(email, "Welcome!") end end # app/controllers/welcome_controller.rb def welcome # blah blah create a @user WelcomeEmailer.perform_async(@user.email) end doesn't block
95. TimKrajcar rate limit by client
96. TimKrajcar Rack::Throttle https://github.com/bendiken/rack-throttle
97. # config/application.rb require 'rack/throttle' class Application < Rails::Application config.middleware.use Rack::Throttle::Hourly, max: 100 end
98. # config/application.rb require 'rack/throttle' class Application < Rails::Application config.middleware.use Rack::Throttle::Hourly, max: 100 end client = by IP or you can define custom client IDs
99. TimKrajcar monitoring & alerting
100. TimKrajcar low traffic? drive synthetic traffic
101. TimKrajcar synthetic-monitor https://github.com/johnboyes/synthetic-monitor
103. TimKrajcar RECAP!!
104. TimKrajcar 1. use Ruby to write services, because it's fun! 2. monitor both request queuing time and app server time 3. make informed framework decisions (use sinatra) 4. set real timeouts and use circuit breakers 5. parallelize everything 6. background everything 7. rate limit by client, even for internal clients 8. drive synthetic traffic to help catch problems right away
105. TimKrajcar references
106. TimKrajcar Nate Berkopec: nateberkopec.com High Scalability: highscalability.com Improved Production Stability With Circuit Breakers: blog.heroku.com
107. TimKrajcar thanks!