GraphQL - APIs The New Way

APIs The New Way

Volodymyr Tsukur

API,

Volodymyr Tsukur

not DB!

Volodymyr Tsukur

Lead Engineer,Guild Master @

Partner @EASYHUNT

Program Committee @JEEConf, XP Days

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Lithuania

Ukraine

Kyiv

Dnipro

Vilnius

Локации Wix Engineering

Israel

Tel Aviv

Be’er Sheva

~ 110M+ users*

~ 700 engineers~ 1800 employees

~ 500 microservices

titlepriceimagesdescriptioninfo...

{

}

GET /products/:id

imagesimages(1)pricepricetitletitle

[

]

description

GET /products

...info

{

}

10%!

OVER-fetching

01

GET /carts/:id

items [ { product quantity total }

{

}

]subTotal

GET /carts/1

GET /products/59eb838e3f

GET /products/59eb88c400

GET /products/59eb838e40

- UNDER-fetching- extra requests

02

GET /carts/1?projection=with-products

...

GET /carts/1?projection=summary

GET /carts/1?projection=

GET /carts/1?projection=

GET /carts/1?projection=with-products

- no unified & widely adopted standard :( *

- harder to collaborate :(

03

How to @deprecate andphase out outdated stuff?

04

2012

2015

“... is a query language for APIs and a runtime for fulfilling those queries with your existing data”

type User { name: String friends: [User] city: City}

type City { name: String population: Int citizens: [User]}

1. Define schema

{ user(name: String): User ...}

2. Ask for data user(name: String): User

2. Ask for data{ user(name: “Vanya Unicorn”) { friends { name } city { name population } }}

3. Get it!{ user(name: “Vanya Unicorn”) { friends { name } city { name population } }}

{ “data”: { “user”: { “friends”: [ { “name”: “Lena” }, { “name”: “Stas” } ] “city”: { “name”: “Kyiv”, “population”: 2928087 } } }}

only necessary data{ “data”: { “user”: { “friends”: [ { “name”: “Lena” }, { “name”: “Stas” } ] “city”: { “name”: “Kyiv”, “population”: 2928087 } } }}

{ user(name: “Vanya Unicorn”) { friends { name } city { name population } }}

in one request *

{ “data”: { “user”: { “friends”: [ { “name”: “Lena” }, { “name”: “Stas” } ] “city”: { “name”: “Kyiv”, “population”: 2928087 } } }}

{ user(name: “Vanya Unicorn”) { friends { name } city { name population } }}

HTTP POST

let us see how it works!

WYSIWYG

efficient fetching

easier to develop

analytics

any data source and transport

graphql-java

HTTP

Cart Service

Product Service

let us rock and roll!

running query

{ cart(id: 1) { items { product { title price images(limit: 1) sku } quantity total } subTotal }}

1)

{ cart(id: 1) { items { product { title price images(limit: 1) sku } quantity total } subTotal }}

2) SELECT ... FROM Cart INNER JOIN Item ...

{ cart(id: 1) { items { product { title price images(limit: 1) sku } quantity total } subTotal }}

3)

+ n x

product { title price images(limit: 1) sku }

product { title price images(limit: 1) sku }

GET /products/1GET /products/2GET /products/3

e x p e c t a t i o n s

Reality

{ cart(id: 1) { items { product { title price images(limit: 1) sku } quantity total } subTotal }}

+

GET /products?ids=1,2,3@Batched

let’s fix it!

Security

{ user(name: “Vanya Unicorn”) { friends { name friends { name friends { name friends { name ... } } } } }}

limit query depth

limit query complexity

let us defend!

throttling / rate limiting

set timeouts

pagination

schema { query: Query}

schema { query: Query, mutation: Mutation}

type Mutation { addProductToCart(cart: ID!, product: ID!, count: Int = 1): Cart}

let us mutate!

+

+

I want it !!!

but let us see the BAD parts

caching

security

error handling

arbitrary resources / file uploads

operation idempotency?

operation naming

hypermedia

Java ecosystem

Alternatives

https://philsturgeon.uk/api/2017/01/24/graphql-vs-rest-overview/

https://blog.runscope.com/posts/you-might-not-need-graphql

NO !!!

but it shines as an integrated solution

schema { query: Query, mutation: Mutation, subscription: Subscription}

type Subscription { productAdded(cart: ID!): Cart}

subscription { productAdded(cart: 123) { items { product ... } subTotal }}

{ “data”: { “productAdded”: { “items”: [ { “product”: ... }, { “product”: ... }, { “product”: ... }, { “product”: ... } ] “subTotal”: 289.33 } }}

://

{ “data”: { “productAdded”: { “items”: [ { “product”: ... }, { “product”: ... }, { “product”: ... }, { “product”: ... } ] “subTotal”: 289.33 } }}

subscription { productAdded(cart: 123) { items { product ... } subTotal }}

://

https://github.com/vtsukur/graphql-java-store

sample, notproduction ready code!

Questions?

[email protected]

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