Radim Štěpaník
Graphql
Graphql
Text
ORCHESTR
ORCHESTR
Radim Štěpaník
Graphql
Graphql
Text
ORCHESTR
ORCHESTR
Radim Štěpaník
Graphql
Graphql
Text
ORCHESTR
ORCHESTR
👀 CTO
🎤 Moderátor
🎸 Kytarista
👨👧 Rodič
(snad lepší než kytarista)
🎧 Listen on spotify
🐦 Follow me on twitter
kinapets
QCAST
Q&A
Q&A
GRAPHQL
GRAPHQL
GRAPHQL
GRAPHQL
Let's build microservices
Let's build microservices
Mobile APP?
Mobile APP?
BFF architecture
BFF architecture
Use GRAPHQL
Use GRAPHQL
What about REST?
What about REST?
GRAPHQL
GRAPHQL
Contract Management
Statically Typed
API Development and Integration
User
Review
Product
String
Int
Boolean
name!
user!
product
isConfirmed
product
reviews
url!
me
products!
boughtProducts
GQL vs REST
type Product {
id: ID!
url: String!
reviews: [Review]
}
type Review {
id: ID!
user: User
product: Product!
isConfirmed: Boolean
}
type User {
id: ID!
name: String
}
type Query {
product(id: ID!): Product
products(url: String!): [Product!]!
me: User
}
GET /v1/products
GET /v1/products/{id}
# reviews vrací pouze referenci na uživatele
GET /v1/products/{id}/reviews
GET /v1/users/{id} GQL vs REST
GQL vs REST
type Product {
id: ID!
url: String!
reviews: [Review]
}
type Review {
id: ID!
user: User
product: Product!
isConfirmed: Boolean
}
type User {
id: ID!
name: String
}
type Query {
product(id: ID!): Product
products(url: String!): [Product!]!
me: User
}
GQL vs REST
// List of products with badges
// of users who created review
{
products {
id
url
reviews {
users {
name
}
}
}
}
GQL vs REST
// List of products with badges
// of users who created review
{
products {
id
url
reviews {
users {
name
}
}
}
}
GQL vs REST
// Step one - get products
GET /v1/products?url=tv
// Step two - load reviews for product
GET /v1/reviews?productId=1
GET /v1/reviews?productId=2
GET /v1/reviews?productId=3
// Step three load users
GET /v1/users/1
GET /v1/users/2
GET /v1/users/1
GET /v1/users/3Define only once
Product
Define only once
User
String
description
creator
Graphql federation
Graphql federation
Distributed systems
Command and conquer
User
Review
Product
String
Int
Boolean
name!
user!
product
isConfirmed
product
reviews
url!
me
products!
boughtProducts
User team
Product team
Graphql federation
Graphql federation
type Product {
id: ID!
url: String!
reviews: [Review]
}
type Review {
id: ID!
user: User
product: Product!
isConfirmed: Boolean
}
type User {
id: ID!
name: String
}
type Query {
product(id: ID!): Product
products(url: String!): [Product!]!
me: User
}
Graphql federation
Graphql federation
# User Subgraph Schema
type User @key(fields: "id") {
id: ID!
name: String
reviews: [Review] @shareable
}
type Review @key(fields: "id") {
id: ID!
user: User! @shareable
isConfirmed: Boolean
product: Product @external
}
extend type Product @key(fields: "id") {
id: ID! @external
}
type Query {
me: User
}# Product Subgraph Schema
type Product @key(fields: "id") {
id: ID!
url: String!
reviews: [Review] @shareable
}
extend type Review @key(fields: "id") {
id: ID! @external
product: Product! @shareable
}
type Query {
product(id: ID!): Product
products(url: String!): [Product!]!
}
Graphql federation
Graphql federation
Graphql federation
Graphql federation
Why use federation?
-
Contracts
-
Fault tolerance
-
Independence
-
Evolution principle - Easy to implement
Why use federation?
Contracts
Contracts
Non blocking principle
Easy to understand
Documentation because of typesafety
Modularity
Responsibility for data
Transparency
Fault tolerance
Fault tolerance
By default supports fault tollerance
Show as much as possible
Independence
Ownership of Schema
Independent Scaling
Communication - contracts again
Independence
Easy to implement
It is still graphql
Service by service
Easy to implement
What to watch out for?
What to watch out for?
Distributed system
- Restart of services
- Communication errors
- Timeouts
- Latencies
Distributed system
Schema nullability
- GQL is strictly typed language
- Response is typesafe
- Delivery service problem
cause problem for
whole query - 👉 Circuit breaker pattern?
type Product {
id: ID!
url: String!
title: String!
estimatedDelivery: EstimatedDelivery!
}
// query
{
products {
id
title
estimatedDelivery {
...
}
}
}
Schema nullability
Performance and security
-
N+1
-
Complex queries
-
Batch query attack
-
Field suggestion attack
Performance and security
🥳 Dataloader
Breaking changes
-
Don't do them
-
Deprecate value with a directive
-
Monitor the usage
Breaking changes
type Category {
id: ID!
imageId: Int @deprecated(reason: "ImageId property is renamed to mediaId")
mediaId: Int
}👋 Díky za pozornost
Dotazy?
Graphql federation
By Radim Štěpaník
