RailsConf 2019: New HotN+1ness - Hard lessons migrating from REST to GraphQL

Our desire to use new tools and learn new technologies backfires when we don't take the time to fully understand them.

In 2018, we migrated from a REST API to GraphQL. Patterns were introduced, copied, pasted, and one day we woke up with queries taking 6s and page load times > 10s. Customers were complaining. How did we get here?

In this talk, we will discuss why we chose GraphQL, show practical examples of the mistakes we made in our implementation, and demonstrate how we eliminated all N+1 queries.

I'll answer the question, "if I knew then what I know now... Would I stick with a REST API?"

Transcript

1. New HotN+1ness Hard lessons migrating from a REST API to GraphQL Eric Allen @_ejallday_
3. Country Load (37.7ms) SELECT 'countries'.* FROM 'countries' LIMIT 10 City Load (2.0ms) SELECT 'cities'.* from 'cities' WHERE 'cities.country_id' = 1 City Load (2.0ms) SELECT 'cities'.* from 'cities' WHERE 'cities.country_id' = 2 City Load (2.0ms) SELECT 'cities'.* from 'cities' WHERE 'cities.country_id' = 3 City Load (2.0ms) SELECT 'cities'.* from 'cities' WHERE 'cities.country_id' = 4 City Load (2.0ms) SELECT 'cities'.* from 'cities' WHERE 'cities.country_id' = 5 City Load (2.0ms) SELECT 'cities'.* from 'cities' WHERE 'cities.country_id' = 6 City Load (2.0ms) SELECT 'cities'.* from 'cities' WHERE 'cities.country_id' = 7 City Load (2.0ms) SELECT 'cities'.* from 'cities' WHERE 'cities.country_id' = 8 City Load (2.0ms) SELECT 'cities'.* from 'cities' WHERE 'cities.country_id' = 9 City Load (2.0ms) SELECT 'cities'.* from 'cities' WHERE 'cities.country_id' = 10 @_ejallday_
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Credential Load (0.3ms) SELECT "credentials".* FROM "credentials" WHERE "credentials"."id" = $1 LIMIT 1 [["id", 1]] Doctor Load (0.3ms) SELECT "doctors".* FROM "doctors" WHERE "doctors"."id" = $1 LIMIT 1 [["id", 1]] Credential Load (0.2ms) SELECT "credentials".* FROM "credentials" WHERE "credentials"."id" = $1 ORDER BY "credentials"."id" ASC LIMIT 1 [["id", 1]] ProviderGroup Load (0.2ms) SELECT "provider_groups".* FROM "provider_groups" WHERE "provider_groups"."id" = $1 LIMIT 1 [["id", 50000]] Stream Load (0.7ms) SELECT "streams".* FROM "streams" INNER JOIN "patients" ON "patients"."id" = "streams"."patient_id" INNER JOIN "plans" ON "streams"."plan_id" = "plans"."id" WHERE "plans"."provider_group_id" = $1 ORDER BY patients.last_name ASC, patients.first_name ASC LIMIT 25 OFFSET 0 [["provider_group_id", 50000]] Encounter Load (0.2ms) SELECT "encounters".* FROM "encounters" WHERE "encounters"."stream_id" = $1 AND "encounters"."state" = 'active' ORDER BY "encounters"."id" ASC LIMIT 1 [["stream_id", 23]] Encounter Load (0.2ms) SELECT "encounters".* FROM "encounters" WHERE "encounters"."id" = $1 LIMIT 1 [["id", "74808465-e9d8-4977-b6e5-fc366ba4446d"]] Stream Load (0.3ms) SELECT "streams".* FROM "streams" WHERE "streams"."id" = $1 LIMIT 1 [["id", 23]] Plan Load (0.2ms) SELECT "plans".* FROM "plans" WHERE "plans"."id" = $1 LIMIT 1 [["id", 1]] PlanConfig Load (0.1ms) SELECT "plan_configs".* FROM "plan_configs" WHERE "plan_configs"."plan_id" = $1 LIMIT 1 [["plan_id", 1]] Plan Load (0.3ms) SELECT "plans".* FROM "plans" INNER JOIN "streams" ON "plans"."id" = "streams"."plan_id" WHERE "streams"."id" = $1 LIMIT 1 [["id", 23]] CACHE (0.0ms) SELECT "plan_configs".* FROM "plan_configs" WHERE "plan_configs"."plan_id" = $1 LIMIT 1 [["plan_id", 1]] Patient Load (0.2ms) SELECT "patients".* FROM "patients" WHERE "patients"."id" = $1 LIMIT 1 [["id", 13]] Credential Load (0.2ms) SELECT "credentials".* FROM "credentials" WHERE "credentials"."owner_id" = $1 AND "credentials"."owner_type" = $2 LIMIT 1 [["owner_id", 13], ["owner_type", "Patient"]] CACHE (0.0ms) SELECT "plans".* FROM "plans" WHERE "plans"."id" = $1 LIMIT 1 [["id", 1]] Encounter Load (0.2ms) SELECT "encounters".* FROM "encounters" WHERE "encounters"."stream_id" = $1 AND "encounters"."state" = 'active' ORDER BY "encounters"."id" ASC LIMIT 1 [["stream_id", 20]] Patient Load (0.2ms) SELECT "patients".* FROM "patients" WHERE "patients"."id" = $1 LIMIT 1 [["id", 10]] Credential Load (0.1ms) SELECT "credentials".* FROM "credentials" WHERE "credentials"."owner_id" = $1 AND "credentials"."owner_type" = $2 LIMIT 1 [["owner_id", 10], ["owner_type", "Patient"]] Plan Load (0.1ms) SELECT "plans".* FROM "plans" WHERE "plans"."id" = $1 LIMIT 1 [["id", 2]] Encounter Load (0.2ms) SELECT "encounters".* FROM "encounters" WHERE "encounters"."stream_id" = $1 AND "encounters"."state" = 'active' ORDER BY "encounters"."id" ASC LIMIT 1 [["stream_id", 19]] Encounter Load (0.2ms) SELECT "encounters".* FROM "encounters" WHERE "encounters"."id" = $1 LIMIT 1 [["id", "11873eca-18f2-45b0-868b-4b0c8f4403f5"]] Stream Load (0.2ms) SELECT "streams".* FROM "streams" WHERE "streams"."id" = $1 LIMIT 1 [["id", 19]] Plan Load (0.2ms) SELECT "plans".* FROM "plans" WHERE "plans"."id" = $1 LIMIT 1 [["id", 1]] PlanConfig Load (0.2ms) SELECT "plan_configs".* FROM "plan_configs" WHERE "plan_configs"."plan_id" = $1 LIMIT 1 [["plan_id", 1]] Plan Load (0.3ms) SELECT "plans".* FROM "plans" INNER JOIN "streams" ON "plans"."id" = "streams"."plan_id" WHERE "streams"."id" = $1 LIMIT 1 [["id", 19]] CACHE (0.0ms) SELECT "plan_configs".* FROM "plan_configs" WHERE "plan_configs"."plan_id" = $1 LIMIT 1 [["plan_id", 1]] Patient Load (0.1ms) SELECT "patients".* FROM "patients" WHERE "patients"."id" = $1 LIMIT 1 [["id", 10]] Credential Load (0.2ms) SELECT "credentials".* FROM "credentials" WHERE "credentials"."owner_id" = $1 AND "credentials"."owner_type" = $2 LIMIT 1 [["owner_id", 10], ["owner_type", "Patient"]] CACHE (0.0ms) SELECT "plans".* FROM "plans" WHERE "plans"."id" = $1 LIMIT 1 [["id", 1]] Encounter Load (0.2ms) SELECT "encounters".* FROM "encounters" WHERE "encounters"."stream_id" = $1 AND "encounters"."state" = 'active' ORDER BY "encounters"."id" ASC LIMIT 1 [["stream_id", 9]] Encounter Load (0.1ms) SELECT "encounters".* FROM "encounters" WHERE "encounters"."id" = $1 LIMIT 1 [["id", "cd6847a1-b490-442d-909f-c2235ece720c"]] Stream Load (0.1ms) SELECT "streams".* FROM "streams" WHERE "streams"."id" = $1 LIMIT 1 [["id", 9]] Plan Load (0.1ms) SELECT "plans".* FROM "plans" WHERE "plans"."id" = $1 LIMIT 1 [["id", 1]] PlanConfig Load (0.1ms) SELECT "plan_configs".* FROM "plan_configs" WHERE "plan_configs"."plan_id" = $1 LIMIT 1 [["plan_id", 1]] Plan Load (0.3ms) SELECT "plans".* FROM "plans" INNER JOIN "streams" ON "plans"."id" = "streams"."plan_id" WHERE "streams"."id" = $1 LIMIT 1 [["id", 9]] CACHE (0.0ms) SELECT "plan_configs".* FROM "plan_configs" WHERE "plan_configs"."plan_id" = $1 LIMIT 1 [["plan_id", 1]] Patient Load (0.1ms) SELECT "patients".* FROM "patients" WHERE "patients"."id" = $1 LIMIT 1 [["id", 5]] Credential Load (0.2ms) SELECT "credentials".* FROM "credentials" WHERE "credentials"."owner_id" = $1 AND "credentials"."owner_type" = $2 LIMIT 1 [["owner_id", 5], ["owner_type", "Patient"]] CACHE (0.0ms) SELECT "plans".* FROM "plans" WHERE "plans"."id" = $1 LIMIT 1 [["id", 1]] Encounter Load (0.2ms) SELECT "encounters".* FROM "encounters" WHERE "encounters"."stream_id" = $1 AND "encounters"."state" = 'active' ORDER BY "encounters"."id" ASC LIMIT 1 [["stream_id", 10]] CACHE (0.0ms) SELECT "patients".* FROM "patients" WHERE "patients"."id" = $1 LIMIT 1 [["id", 5]] CACHE (0.0ms) SELECT "credentials".* FROM "credentials" WHERE "credentials"."owner_id" = $1 AND "credentials"."owner_type" = $2 LIMIT 1 [["owner_id", 5], ["owner_type", "Patient"]] Plan Load (0.2ms) SELECT "plans".* FROM "plans" WHERE "plans"."id" = $1 LIMIT 1 [["id", 2]] Encounter Load (0.1ms) SELECT "encounters".* FROM "encounters" WHERE "encounters"."stream_id" = $1 AND "encounters"."state" = 'active' ORDER BY "encounters"."id" ASC LIMIT 1 [["stream_id", 4]] Patient Load (0.1ms) SELECT "patients".* FROM "patients" WHERE "patients"."id" = $1 LIMIT 1 [["id", 2]] Credential Load (0.2ms) SELECT "credentials".* FROM "credentials" WHERE "credentials"."owner_id" = $1 AND "credentials"."owner_type" = $2 LIMIT 1 [["owner_id", 2], ["owner_type", "Patient"]] CACHE (0.0ms) SELECT "plans".* FROM "plans" WHERE "plans"."id" = $1 LIMIT 1 [["id", 2]] Encounter Load (0.1ms) SELECT "encounters".* FROM "encounters" WHERE "encounters"."stream_id" = $1 AND "encounters"."state" = 'active' ORDER BY "encounters"."id" ASC LIMIT 1 [["stream_id", 3]] Encounter Load (0.1ms) SELECT "encounters".* FROM "encounters" WHERE "encounters"."id" = $1 LIMIT 1 [["id", "19095b47-592d-4687-9cc2-396def04a971"]] Stream Load (0.2ms) SELECT "streams".* FROM "streams" WHERE "streams"."id" = $1 LIMIT 1 [["id", 3]] Plan Load (0.1ms) SELECT "plans".* FROM "plans" WHERE "plans"."id" = $1 LIMIT 1 [["id", 1]] PlanConfig Load (0.1ms) SELECT "plan_configs".* FROM "plan_configs" WHERE "plan_configs"."plan_id" = $1 LIMIT 1 [["plan_id", 1]] Plan Load (0.3ms) SELECT "plans".* FROM "plans" INNER JOIN "streams" ON "plans"."id" = "streams"."plan_id" WHERE "streams"."id" = $1 LIMIT 1 [["id", 3]] CACHE (0.0ms) SELECT "plan_configs".* FROM "plan_configs" WHERE "plan_configs"."plan_id" = $1 LIMIT 1 [["plan_id", 1]] Patient Load (0.3ms) SELECT "patients".* FROM "patients" WHERE "patients"."id" = $1 LIMIT 1 [["id", 2]] Credential Load (0.2ms) SELECT "credentials".* FROM "credentials" WHERE "credentials"."owner_id" = $1 AND "credentials"."owner_type" = $2 LIMIT 1 [["owner_id", 2], ["owner_type", "Patient"]] CACHE (0.0ms) SELECT "plans".* FROM "plans" WHERE "plans"."id" = $1 LIMIT 1 [["id", 1]] Encounter Load (0.2ms) SELECT "encounters".* FROM "encounters" WHERE "encounters"."stream_id" = $1 AND "encounters"."state" = 'active' ORDER BY "encounters"."id" ASC LIMIT 1 [["stream_id", 1]] Encounter Load (0.2ms) SELECT "encounters".* FROM "encounters" WHERE "encounters"."id" = $1 LIMIT 1 [["id", "a9526e2b-b9ed-47b4-91b6-3da3c2e3f586"]] Stream Load (0.2ms) SELECT "streams".* FROM "streams" WHERE "streams"."id" = $1 LIMIT 1 [["id", 1]] @_ejallday_
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14. Why am I here? And, why I'm gonna take about 40 minutes of your time. @_ejallday_
15. • I ❤ API's & Performance @_ejallday_
16. • I ❤ API's & Performance • I ❤ decisions that are good for the business @_ejallday_
17. • I ❤ API's & Performance • I ❤ decisions that are good for the business • I ❤ software community @_ejallday_
18. ! @_ejallday_
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28. https://my.cirrusmd.com/ streams @_ejallday_
29. @_ejallday_
30. gem 'graphql' @_ejallday_
31. GraphQL is a query language for APIs and a runtime for fulfilling those queries with your existing data. GraphQL provides a complete and understandable description of the data in your API, gives clients the power to ask for exactly what they need and nothing more, makes it easier to evolve APIs over time, and enables powerful developer tools. -- graphql.org @_ejallday_
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34. REST API class Api::V1::StreamsController < Api::V1::ApplicationController def index streams = Stream.all.includes( :plan, encounters: [:provider, :patient], patient: :credential ) render json: CollectionSerializer.new( streams, serializer: StreamSerializer, path: request.url ).as_json end end @_ejallday_
35. GraphQL class Resolvers::Streams < Resolvers::BaseResolver description 'Get all streams' type [Types::StreamType], null: false def resolve Stream.all.includes( :plan, encounters: [:provider, :patient], patient: :credential ) end end @_ejallday_
36. REST API class Api::V1::StreamsController < Api::V1::ApplicationController def index streams = Stream.all.includes( :plan, encounters: [:provider, :patient], patient: :credential ) render json: CollectionSerializer.new( streams, serializer: StreamSerializer, path: request.url ).as_json end end @_ejallday_
37. GraphQL class Resolvers::Streams < Resolvers::BaseResolver description 'Get all streams' type [Types::StreamType], null: false def resolve Stream.all.includes( :plan, encounters: [:provider, :patient], patient: :credential ) end end @_ejallday_
38. REST API class Api::V1::StreamSerializer < ActiveModel::Serializer attributes :id, :active_encounter has_one :patient, serializer: PatientSerializer has_one :plan, serializer: PlanSerializer def active_encounter EncounterSerializer.new(object.encounters.first) end end @_ejallday_
39. GraphQL class Types::StreamType < Types::BaseObject graphql_name 'Stream' description 'A stream' field :id, String, null: false field :active_encounter, Types::EncounterType, null: true field :patient, Types::PatientType, null: false field :plan, Types::PlanType, null: false def active_encounter object.encounters.first end end @_ejallday_
40. REST API class Api::V1::StreamSerializer < ActiveModel::Serializer attributes :id, :active_encounter has_one :patient, serializer: PatientSerializer has_one :plan, serializer: PlanSerializer def active_encounter EncounterSerializer.new(object.encounters.first) end end @_ejallday_
41. GraphQL class Types::StreamType < Types::BaseObject graphql_name 'Stream' description 'A stream' field :id, String, null: false field :active_encounter, Types::EncounterType, null: true field :patient, Types::PatientType, null: false field :plan, Types::PlanType, null: false def active_encounter object.encounters.first end end @_ejallday_
42. Credential Load (0.3ms) SELECT "credentials".* FROM "credentials" WHERE "credentials"."id" = $1 LIMIT 1 [["id", 1]] Doctor Load (0.3ms) SELECT "doctors".* FROM "doctors" WHERE "doctors"."id" = $1 LIMIT 1 [["id", 1]] Credential Load (0.2ms) SELECT "credentials".* FROM "credentials" WHERE "credentials"."id" = $1 ORDER BY "credentials"."id" ASC LIMIT 1 [["id", 1]] ProviderGroup Load (0.2ms) SELECT "provider_groups".* FROM "provider_groups" WHERE "provider_groups"."id" = $1 LIMIT 1 [["id", 50000]] Stream Load (0.7ms) SELECT "streams".* FROM "streams" INNER JOIN "patients" ON "patients"."id" = "streams"."patient_id" INNER JOIN "plans" ON "streams"."plan_id" = "plans"."id" WHERE "plans"."provider_group_id" = $1 ORDER BY patients.last_name ASC, patients.first_name ASC LIMIT 25 OFFSET 0 [["provider_group_id", 50000]] Encounter Load (0.2ms) SELECT "encounters".* FROM "encounters" WHERE "encounters"."stream_id" = $1 AND "encounters"."state" = 'active' ORDER BY "encounters"."id" ASC LIMIT 1 [["stream_id", 23]] Encounter Load (0.2ms) SELECT "encounters".* FROM "encounters" WHERE "encounters"."id" = $1 LIMIT 1 [["id", "74808465-e9d8-4977-b6e5-fc366ba4446d"]] Stream Load (0.3ms) SELECT "streams".* FROM "streams" WHERE "streams"."id" = $1 LIMIT 1 [["id", 23]] Plan Load (0.2ms) SELECT "plans".* FROM "plans" WHERE "plans"."id" = $1 LIMIT 1 [["id", 1]] PlanConfig Load (0.1ms) SELECT "plan_configs".* FROM "plan_configs" WHERE "plan_configs"."plan_id" = $1 LIMIT 1 [["plan_id", 1]] Plan Load (0.3ms) SELECT "plans".* FROM "plans" INNER JOIN "streams" ON "plans"."id" = "streams"."plan_id" WHERE "streams"."id" = $1 LIMIT 1 [["id", 23]] CACHE (0.0ms) SELECT "plan_configs".* FROM "plan_configs" WHERE "plan_configs"."plan_id" = $1 LIMIT 1 [["plan_id", 1]] Patient Load (0.2ms) SELECT "patients".* FROM "patients" WHERE "patients"."id" = $1 LIMIT 1 [["id", 13]] Credential Load (0.2ms) SELECT "credentials".* FROM "credentials" WHERE "credentials"."owner_id" = $1 AND "credentials"."owner_type" = $2 LIMIT 1 [["owner_id", 13], ["owner_type", "Patient"]] CACHE (0.0ms) SELECT "plans".* FROM "plans" WHERE "plans"."id" = $1 LIMIT 1 [["id", 1]] Encounter Load (0.2ms) SELECT "encounters".* FROM "encounters" WHERE "encounters"."stream_id" = $1 AND "encounters"."state" = 'active' ORDER BY "encounters"."id" ASC LIMIT 1 [["stream_id", 20]] Patient Load (0.2ms) SELECT "patients".* FROM "patients" WHERE "patients"."id" = $1 LIMIT 1 [["id", 10]] Credential Load (0.1ms) SELECT "credentials".* FROM "credentials" WHERE "credentials"."owner_id" = $1 AND "credentials"."owner_type" = $2 LIMIT 1 [["owner_id", 10], ["owner_type", "Patient"]] Plan Load (0.1ms) SELECT "plans".* FROM "plans" WHERE "plans"."id" = $1 LIMIT 1 [["id", 2]] Encounter Load (0.2ms) SELECT "encounters".* FROM "encounters" WHERE "encounters"."stream_id" = $1 AND "encounters"."state" = 'active' ORDER BY "encounters"."id" ASC LIMIT 1 [["stream_id", 19]] Encounter Load (0.2ms) SELECT "encounters".* FROM "encounters" WHERE "encounters"."id" = $1 LIMIT 1 [["id", "11873eca-18f2-45b0-868b-4b0c8f4403f5"]] Stream Load (0.2ms) SELECT "streams".* FROM "streams" WHERE "streams"."id" = $1 LIMIT 1 [["id", 19]] Plan Load (0.2ms) SELECT "plans".* FROM "plans" WHERE "plans"."id" = $1 LIMIT 1 [["id", 1]] PlanConfig Load (0.2ms) SELECT "plan_configs".* FROM "plan_configs" WHERE "plan_configs"."plan_id" = $1 LIMIT 1 [["plan_id", 1]] Plan Load (0.3ms) SELECT "plans".* FROM "plans" INNER JOIN "streams" ON "plans"."id" = "streams"."plan_id" WHERE "streams"."id" = $1 LIMIT 1 [["id", 19]] CACHE (0.0ms) SELECT "plan_configs".* FROM "plan_configs" WHERE "plan_configs"."plan_id" = $1 LIMIT 1 [["plan_id", 1]] Patient Load (0.1ms) SELECT "patients".* FROM "patients" WHERE "patients"."id" = $1 LIMIT 1 [["id", 10]] Credential Load (0.2ms) SELECT "credentials".* FROM "credentials" WHERE "credentials"."owner_id" = $1 AND "credentials"."owner_type" = $2 LIMIT 1 [["owner_id", 10], ["owner_type", "Patient"]] CACHE (0.0ms) SELECT "plans".* FROM "plans" WHERE "plans"."id" = $1 LIMIT 1 [["id", 1]] Encounter Load (0.2ms) SELECT "encounters".* FROM "encounters" WHERE "encounters"."stream_id" = $1 AND "encounters"."state" = 'active' ORDER BY "encounters"."id" ASC LIMIT 1 [["stream_id", 9]] Encounter Load (0.1ms) SELECT "encounters".* FROM "encounters" WHERE "encounters"."id" = $1 LIMIT 1 [["id", "cd6847a1-b490-442d-909f-c2235ece720c"]] Stream Load (0.1ms) SELECT "streams".* FROM "streams" WHERE "streams"."id" = $1 LIMIT 1 [["id", 9]] Plan Load (0.1ms) SELECT "plans".* FROM "plans" WHERE "plans"."id" = $1 LIMIT 1 [["id", 1]] PlanConfig Load (0.1ms) SELECT "plan_configs".* FROM "plan_configs" WHERE "plan_configs"."plan_id" = $1 LIMIT 1 [["plan_id", 1]] Plan Load (0.3ms) SELECT "plans".* FROM "plans" INNER JOIN "streams" ON "plans"."id" = "streams"."plan_id" WHERE "streams"."id" = $1 LIMIT 1 [["id", 9]] CACHE (0.0ms) SELECT "plan_configs".* FROM "plan_configs" WHERE "plan_configs"."plan_id" = $1 LIMIT 1 [["plan_id", 1]] Patient Load (0.1ms) SELECT "patients".* FROM "patients" WHERE "patients"."id" = $1 LIMIT 1 [["id", 5]] Credential Load (0.2ms) SELECT "credentials".* FROM "credentials" WHERE "credentials"."owner_id" = $1 AND "credentials"."owner_type" = $2 LIMIT 1 [["owner_id", 5], ["owner_type", "Patient"]] CACHE (0.0ms) SELECT "plans".* FROM "plans" WHERE "plans"."id" = $1 LIMIT 1 [["id", 1]] Encounter Load (0.2ms) SELECT "encounters".* FROM "encounters" WHERE "encounters"."stream_id" = $1 AND "encounters"."state" = 'active' ORDER BY "encounters"."id" ASC LIMIT 1 [["stream_id", 10]] CACHE (0.0ms) SELECT "patients".* FROM "patients" WHERE "patients"."id" = $1 LIMIT 1 [["id", 5]] CACHE (0.0ms) SELECT "credentials".* FROM "credentials" WHERE "credentials"."owner_id" = $1 AND "credentials"."owner_type" = $2 LIMIT 1 [["owner_id", 5], ["owner_type", "Patient"]] Plan Load (0.2ms) SELECT "plans".* FROM "plans" WHERE "plans"."id" = $1 LIMIT 1 [["id", 2]] Encounter Load (0.1ms) SELECT "encounters".* FROM "encounters" WHERE "encounters"."stream_id" = $1 AND "encounters"."state" = 'active' ORDER BY "encounters"."id" ASC LIMIT 1 [["stream_id", 4]] Patient Load (0.1ms) SELECT "patients".* FROM "patients" WHERE "patients"."id" = $1 LIMIT 1 [["id", 2]] Credential Load (0.2ms) SELECT "credentials".* FROM "credentials" WHERE "credentials"."owner_id" = $1 AND "credentials"."owner_type" = $2 LIMIT 1 [["owner_id", 2], ["owner_type", "Patient"]] CACHE (0.0ms) SELECT "plans".* FROM "plans" WHERE "plans"."id" = $1 LIMIT 1 [["id", 2]] Encounter Load (0.1ms) SELECT "encounters".* FROM "encounters" WHERE "encounters"."stream_id" = $1 AND "encounters"."state" = 'active' ORDER BY "encounters"."id" ASC LIMIT 1 [["stream_id", 3]] Encounter Load (0.1ms) SELECT "encounters".* FROM "encounters" WHERE "encounters"."id" = $1 LIMIT 1 [["id", "19095b47-592d-4687-9cc2-396def04a971"]] Stream Load (0.2ms) SELECT "streams".* FROM "streams" WHERE "streams"."id" = $1 LIMIT 1 [["id", 3]] Plan Load (0.1ms) SELECT "plans".* FROM "plans" WHERE "plans"."id" = $1 LIMIT 1 [["id", 1]] PlanConfig Load (0.1ms) SELECT "plan_configs".* FROM "plan_configs" WHERE "plan_configs"."plan_id" = $1 LIMIT 1 [["plan_id", 1]] Plan Load (0.3ms) SELECT "plans".* FROM "plans" INNER JOIN "streams" ON "plans"."id" = "streams"."plan_id" WHERE "streams"."id" = $1 LIMIT 1 [["id", 3]] CACHE (0.0ms) SELECT "plan_configs".* FROM "plan_configs" WHERE "plan_configs"."plan_id" = $1 LIMIT 1 [["plan_id", 1]] Patient Load (0.3ms) SELECT "patients".* FROM "patients" WHERE "patients"."id" = $1 LIMIT 1 [["id", 2]] Credential Load (0.2ms) SELECT "credentials".* FROM "credentials" WHERE "credentials"."owner_id" = $1 AND "credentials"."owner_type" = $2 LIMIT 1 [["owner_id", 2], ["owner_type", "Patient"]] CACHE (0.0ms) SELECT "plans".* FROM "plans" WHERE "plans"."id" = $1 LIMIT 1 [["id", 1]] Encounter Load (0.2ms) SELECT "encounters".* FROM "encounters" WHERE "encounters"."stream_id" = $1 AND "encounters"."state" = 'active' ORDER BY "encounters"."id" ASC LIMIT 1 [["stream_id", 1]] Encounter Load (0.2ms) SELECT "encounters".* FROM "encounters" WHERE "encounters"."id" = $1 LIMIT 1 [["id", "a9526e2b-b9ed-47b4-91b6-3da3c2e3f586"]] Stream Load (0.2ms) SELECT "streams".* FROM "streams" WHERE "streams"."id" = $1 LIMIT 1 [["id", 1]]** @_ejallday_
43. Lesson no. 1 Eager Loading @_ejallday_
44. class Resolvers::Streams < Resolvers::BaseResolver description 'Get all streams' type [Types::StreamType], null: false def resolve Stream.all.includes( :plan, encounters: [:provider, :patient], patient: :credential ) end end @_ejallday_
45. class Resolvers::Streams < Resolvers::BaseResolver description 'Get all streams' type [Types::StreamType], null: false def resolve Stream.all.includes( :plan, encounters: [:provider, :patient], patient: :credential ) end end @_ejallday_
46. query Streams($limit: Int, $page: Int) { streams(limit: $limit, page: $page) { data { id activeEncounter { ...Encounter { provider { ...Provider } state } patient { ...Patient } plan { ...Plan } } } } @_ejallday_
47. query Streams($limit: Int, $page: Int) { streams(limit: $limit, page: $page) { data { id } } } @_ejallday_
48. class Resolvers::Streams < Resolvers::BaseResolver description 'Get all streams' type [Types::StreamType], null: false def resolve Stream.all end end @_ejallday_
49. class Types::StreamType < Types::BaseObject graphql_name 'Stream' description 'A stream' field :id, String, null: false field :active_encounter, Types::EncounterType, null: true field :patient, Types::PatientType, null: false field :plan, Types::PlanType, null: false def active_encounter object.encounters.first end end @_ejallday_
50. gem 'graphql-batch' @_ejallday_
51. class RecordLoader < GraphQL::Batch::Loader def initialize(model, column: model.primary_key, where: nil) @model = model @column = column.to_s @column_type = model.type_for_attribute(@column) @where = where end def load(key) super(@column_type.cast(key)) end def perform(keys) query(keys).each { |record| fulfill(record.public_send(@column), record) } keys.each { |key| fulfill(key, nil) unless fulfilled?(key) } end private def query(keys) scope = @model scope = scope.where(@where) if @where scope.where(@column => keys) end end @_ejallday_
52. class Types::StreamType < Types::BaseObject field :id, String, null: false field :active_encounter, Types::EncounterType, null: true field :patient, Types::PatientType, null: false field :plan, Types::PlanType, null: false def active_encounter AssociationLoader.for(Stream, :encounters).load(object).then(&:first) end def patient RecordLoader.for(Patient).load(object.patient_id) end def plan RecordLoader.for(Plan).load(object.plan_id) end end @_ejallday_
53. class Types::StreamType < Types::BaseObject field :id, String, null: false field :active_encounter, Types::EncounterType, null: true field :patient, Types::PatientType, null: false field :plan, Types::PlanType, null: false def active_encounter AssociationLoader.for(Stream, :encounters).load(object).then(&:first) end def patient RecordLoader.for(Patient).load(object.patient_id) end def plan RecordLoader.for(Plan).load(object.plan_id) end end @_ejallday_
54. Credential Load (0.3ms) SELECT "credentials".* FROM "credentials" WHERE "credentials"."id" = $1 LIMIT 1 [["id", 1]] Doctor Load (0.2ms) SELECT "doctors".* FROM "doctors" WHERE "doctors"."id" = $1 LIMIT 1 [["id", 1]] Credential Load (0.2ms) SELECT "credentials".* FROM "credentials" WHERE "credentials"."id" = $1 ORDER BY... ProviderGroup Load (0.3ms) SELECT "provider_groups".* FROM "provider_groups" WHERE "provider_groups"."id" =... Stream Load (0.8ms) SELECT "streams".* FROM "streams" INNER JOIN "patients" ON "patients"."id" =... "plans" ON "streams"."plan_id" = "plans"."id" WHERE "plans"."provider_group_id" = $1 ORDER BY... (0.6ms) SELECT COUNT(*) FROM "streams" INNER JOIN "patients" ON "patients"."id" = "streams"."patient_id" INNER JOIN "plans" ON "streams"."plan_id" = "plans"."id" WHERE "plans"."provider_group_id" = $1... Encounter Load (0.4ms) SELECT "encounters".* FROM "encounters" WHERE "encounters"."stream_id" IN (23, 20, 19, 9, 10, 4, 3, 1, 2, 5, 6, 14, 13, 11, 12, 16, 15, 22, 17, 18, 7, 8, 21) Encounter Load (0.2ms) SELECT "encounters".* FROM "encounters" WHERE "encounters"."id" = $1 LIMIT 1... Stream Load (0.2ms) SELECT "streams".* FROM "streams" WHERE "streams"."id" = $1 LIMIT 1 [["id", 23]] Plan Load (0.2ms) SELECT "plans".* FROM "plans" WHERE "plans"."id" = $1 LIMIT 1 [["id", 1]] PlanConfig Load (0.2ms) SELECT "plan_configs".* FROM "plan_configs" WHERE "plan_configs"."plan_id" = $1 LIMIT 1... Plan Load (0.2ms) SELECT "plans".* FROM "plans" INNER JOIN "streams" ON "plans"."id" = "streams"."plan_id" WHERE... CACHE (0.0ms) SELECT "plan_configs".* FROM "plan_configs" WHERE "plan_configs"."plan_id" = $1 LIMIT 1 [["plan_id", 1]] Patient Load (0.5ms) SELECT "patients".* FROM "patients" WHERE "patients"."id" IN (13, 10, 5, 2, 1, 3, 7, 6, 8, 12, 9, 4, 11) Credential Load (0.2ms) SELECT "credentials".* FROM "credentials" WHERE "credentials"."owner_id" = $1 AND... Plan Load (0.2ms) SELECT "plans".* FROM "plans" WHERE "plans"."id" IN (1, 2) Credential Load (0.1ms) SELECT "credentials".* FROM "credentials" WHERE "credentials"."owner_id" = $1 AND... Encounter Load (0.2ms) SELECT "encounters".* FROM "encounters" WHERE "encounters"."id" = $1 LIMIT 1... Stream Load (0.1ms) SELECT "streams".* FROM "streams" WHERE "streams"."id" = $1 LIMIT 1 [["id", 19]] Plan Load (0.1ms) SELECT "plans".* FROM "plans" WHERE "plans"."id" = $1 LIMIT 1 [["id", 1]] PlanConfig Load (0.1ms) SELECT "plan_configs".* FROM "plan_configs" WHERE "plan_configs"."plan_id" = $1 LIMIT 1...i* @_ejallday_
55. Lesson no. 2 Delegation @_ejallday_
56. class Types::StreamType < Types::BaseObject field :id, String, null: false field :active_encounter, Types::EncounterType, null: true field :patient, Types::PatientType, null: false field :plan, Types::PlanType, null: false def active_encounter AssociationLoader.for(Stream, :encounters).load(object).then(&:first) end def patient RecordLoader.for(Patient).load(object.patient_id) end def plan RecordLoader.for(Plan).load(object.plan_id) end end @_ejallday_
57. class Types::StreamType < Types::BaseObject ... field :patient, Types::PatientType, null: false def patient RecordLoader.for(Patient).load(object.patient_id) end ... end @_ejallday_
58. class Types::PatientType < Types::BaseObject graphql_name 'Patient' description 'A patient' field :id, ID, null: false field :dob, Types::Scalar::DateType, null: false field :email, String, null: false field :first_name, String, null: false field :gender, String, null: false field :last_name, String, null: false end @_ejallday_
59. class Patient < ActiveRecord::Base ... has_one :credential delegate :email, to: :credential end @_ejallday_
60. class Patient < ActiveRecord::Base ... has_one :credential delegate :email, to: :credential end @_ejallday_
61. class Types::PatientType < Types::BaseObject ... field :email, String, null: false def email RecordLoader.for(Credential) .load(object.credential_id) .then(&:email) end end @_ejallday_
62. class Types::PatientType < Types::BaseObject ... field :email, String, null: false def email RecordLoader.for(Credential) .load(object.credential_id) .then(&:email) end end @_ejallday_
63. Credential Load (0.2ms) SELECT "credentials".* FROM "credentials" WHERE "credentials"."id" = $1 LIMIT 1 [["id", 1]] Doctor Load (0.1ms) SELECT "doctors".* FROM "doctors" WHERE "doctors"."id" = $1 LIMIT 1 [["id", 1]] Credential Load (0.1ms) SELECT "credentials".* FROM "credentials" WHERE "credentials"."id" = $1... ProviderGroup Load (0.3ms) SELECT "provider_groups".* FROM "provider_groups" WHERE "provider_groups"."id" =... Stream Load (0.8ms) SELECT "streams".* FROM "streams" INNER JOIN "patients" ON "patients"."id" = "streams"."patient_id" INNER JOIN "plans" ON "streams"."plan_id" = "plans"."id" WHERE "plans"."provider_group_id" = $1 (0.5ms) SELECT COUNT(*) FROM "streams" INNER JOIN "patients" ON "patients"."id" = "streams"."patient_id" INNER JOIN "plans" ON "streams"."plan_id" = "plans"."id" WHERE "plans"."provider_group_id" = $1 [["provider_group_id", 50000]] Encounter Load (0.4ms) SELECT "encounters".* FROM "encounters" WHERE "encounters"."stream_id" IN (23, 20, 19, 9, 10, 4, 3, 1, 2, 5, 6, 14, 13, 11, 12, 16, 15, 22, 17, 18, 7, 8, 21) Credential Load (0.3ms) SELECT "credentials".* FROM "credentials" WHERE "credentials"."id" IN (23, 20, 15, 12, 11, 13, 17, 16, 18, 22, 19, 14, 21) Encounter Load (0.2ms) SELECT "encounters".* FROM "encounters" WHERE "encounters"."id" = $1 LIMIT 1... Stream Load (0.1ms) SELECT "streams".* FROM "streams" WHERE "streams"."id" = $1 LIMIT 1 [["id", 23]] Plan Load (0.1ms) SELECT "plans".* FROM "plans" WHERE "plans"."id" = $1 LIMIT 1 [["id", 1]] PlanConfig Load (0.1ms) SELECT "plan_configs".* FROM "plan_configs" WHERE "plan_configs"."plan_id" = $1 LIMIT 1... Plan Load (0.3ms) SELECT "plans".* FROM "plans" INNER JOIN "streams" ON "plans"."id" = "streams"."plan_id" WHERE... CACHE (0.0ms) SELECT "plan_configs".* FROM "plan_configs" WHERE "plan_configs"."plan_id" = $1 LIMIT 1 [["plan_id", 1]] Patient Load (0.3ms) SELECT "patients".* FROM "patients" WHERE "patients"."id" IN (13, 10, 5, 2, 1, 3, 7, 6, 8, 12, 9, 4, 11) Plan Load (0.3ms) SELECT "plans".* FROM "plans" WHERE "plans"."id" IN (1, 2) Encounter Load (0.1ms) SELECT "encounters".* FROM "encounters" WHERE "encounters"."id" = $1 LIMIT 1... Stream Load (0.1ms) SELECT "streams".* FROM "streams" WHERE "streams"."id" = $1 LIMIT 1 [["id", 19]] Plan Load (0.2ms) SELECT "plans".* FROM "plans" WHERE "plans"."id" = $1 LIMIT 1 [["id", 1]] PlanConfig Load (0.1ms) SELECT "plan_configs".* FROM "plan_configs" WHERE "plan_configs"."plan_id" = $1 LIMIT 1... Plan Load (0.3ms) SELECT "plans".* FROM "plans" INNER JOIN "streams" ON "plans"."id" = "streams"."plan_id" WHERE... CACHE (0.0ms) SELECT "plan_configs".* FROM "plan_configs" WHERE "plan_configs"."plan_id" = $1 LIMIT 1 [["plan_id", 1]] Encounter Load (0.3ms) SELECT "encounters".* FROM "encounters" WHERE "encounters"."id" = $1 LIMIT 1... Stream Load (0.1ms) SELECT "streams".* FROM "streams" WHERE "streams"."id" = $1 LIMIT 1 [["id", 9]] Plan Load (0.1ms) SELECT "plans".* FROM "plans" WHERE "plans"."id" = $1 LIMIT 1 [["id", 1]] PlanConfig Load (0.2ms) SELECT "plan_configs".* FROM "plan_configs" WHERE "plan_configs"."plan_id" = $1 LIMIT 1... Plan Load (0.2ms) SELECT "plans".* FROM "plans" INNER JOIN "streams" ON "plans"."id" = "streams"."plan_id" WHERE... CACHE (0.0ms) SELECT "plan_configs".* FROM "plan_configs" WHERE "plan_configs"."plan_id" = $1 LIMIT 1 [["plan_id", 1]] @_ejallday_
64. Lesson no. 3 Service Objects / Decorators @_ejallday_
65. class Types::StreamType < Types::BaseObject ... field :active_encounter, Types::EncounterType, null: true def active_encounter AssociationLoader.for(Stream, :encounters) .load(object) .then(&:first) end ... end @_ejallday_
66. class Types::EncounterType < Types::BaseObject ... field :patient_queue_status, Types::PatientQueueStatusType def patient_queue_status PatientQueueStatus.for(encounter: object) end end @_ejallday_
67. class PatientQueueStatus def self.for(encounter:) stream = encounter.stream plan = stream.plan unless encounter.completed? || stream.inactive? { message: "Operating Hours are between..." } end end end @_ejallday_
68. class PatientQueueStatus def self.for(encounter:) stream = encounter.stream plan = stream.plan unless encounter.completed? || stream.inactive? { message: "Operating Hours are between..." } end end end @_ejallday_
69. class Types::EncounterType < Types::BaseObject ... field :patient_queue_status, Types::PatientQueueStatusType def patient_queue_status PatientQueueStatus.for(encounter: object) end end @_ejallday_
70. class Types::EncounterType < Types::BaseObject ... field :patient_queue_status, Types::PatientQueueStatusType def stream RecordLoader.for(Stream).load(object.stream_id) end def plan stream.then do |stream| RecordLoader.for(Plan).load(stream.plan_id) end end def patient_queue_status Promise.all([stream, plan]).then do |results| PatientQueueStatus.for( encounter: object, stream: results[0], plan: results[1] ) end end end @_ejallday_
71. class Types::EncounterType < Types::BaseObject ... def patient_queue_status Promise.all([stream, plan]).then do |results| PatientQueueStatus.for( encounter: object, stream: results[0], plan: results[1] ) end end end @_ejallday_
72. Credential Load (0.4ms) SELECT "credentials".* FROM "credentials" WHERE "credentials"."id" = $1 LIMIT 1 [["id", 1]] Doctor Load (0.3ms) SELECT "doctors".* FROM "doctors" WHERE "doctors"."id" = $1 LIMIT 1 [["id", 1]] Credential Load (0.2ms) SELECT "credentials".* FROM "credentials" WHERE "credentials"."id" = $1 ORDER BY... ProviderGroup Load (0.6ms) SELECT "provider_groups".* FROM "provider_groups" WHERE "provider_groups"."id" = ... Stream Load (8.4ms) SELECT "streams".* FROM "streams" INNER JOIN "patients" ON "patients"."id" = "streams"."patient_id" INNER JOIN "plans" ON "streams"."plan_id" = "plans"."id" WHERE "plans"."provider_group_id" = $1 ... (1.9ms) SELECT COUNT(*) FROM "streams" INNER JOIN "patients" ON "patients"."id" = "streams"."patient_id" INNER JOIN... Encounter Load (0.7ms) SELECT "encounters".* FROM "encounters" WHERE "encounters"."stream_id" IN (23, 20, 19, 9, 10, 4, 3, 1, 2, 5, 6, 14, 13, 11, 12, 16, 15, 22, 17, 18, 7, 8, 21) Patient Load (0.4ms) SELECT "patients".* FROM "patients" WHERE "patients"."id" IN (13, 10, 5, 2, 1, 3, 7, 6, 8, 12, 9, 4, 11) Plan Load (0.2ms) SELECT "plans".* FROM "plans" WHERE "plans"."id" IN (1, 2) Stream Load (0.4ms) SELECT "streams".* FROM "streams" WHERE "streams"."id" IN (23, 19, 9, 3, 1, 5, 13, 11, 15, 22, 17, 7, 21) Doctor Load (0.2ms) SELECT "doctors".* FROM "doctors" WHERE "doctors"."id" = 1 Credential Load (0.3ms) SELECT "credentials".* FROM "credentials" WHERE "credentials"."id" IN (23, 20, 15, 12, 11, 13, 17, 16, 18, 22, 19, 14, 21) @_ejallday_
73. Recap • Eager loading • Method delegation • Decorators and service objects @_ejallday_
74. @_ejallday_
75. Retro? @_ejallday_
76. What did we gain? @_ejallday_
77. What did we gain? • Flexibility @_ejallday_
78. What did we gain? • Flexibility • FREE documentation @_ejallday_
79. What did we gain? • Flexibility • FREE documentation • New Dependencies graphql & graphql- batch @_ejallday_
80. What did we give up? @_ejallday_
81. What did we give up? • Confidence (for a short while, and was certainly avoidable) @_ejallday_
82. What did we give up? • Confidence (for a short while, and was certainly avoidable) • HTTP Response codes @_ejallday_
83. What did we give up? • Confidence (for a short while, and was certainly avoidable) • HTTP Response codes • Granularity in performance monitoring @_ejallday_
84. What did we give up? • Confidence (for a short while, and was certainly avoidable) • HTTP Response codes • Granularity in performance monitoring • Feature work @_ejallday_
85. How can we approach our decisions differently? @_ejallday_
86. @_ejallday_
87. Ideas for better decision making • Remove opinions that are presented as facts @_ejallday_
88. Ideas for better decision making • Remove opinions that are presented as facts • Say "I don't know" or "I'm not sure" more often @_ejallday_
89. Ideas for better decision making • Remove opinions that are presented as facts • Say "I don't know" or "I'm not sure" more often • Embrace uncertainty @_ejallday_
90. Ideas for better decision making • Remove opinions that are presented as facts • Say "I don't know" or "I'm not sure" more often • Embrace uncertainty • Focus on the process @_ejallday_
91. Ideas for better decision making • Remove opinions that are presented as facts • Say "I don't know" or "I'm not sure" more often • Embrace uncertainty • Focus on the process • Remove bias based on the desire to learn a new tool @_ejallday_
92. Embrace Mistakes @_ejallday_
93. Thank you. @_ejallday_
94. Questions? @_ejallday_