Spring Cloud DCJUG · Spencer Gibb

Example Distributed System: Minified

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Features

Bootstrap phase
Distributed configuration
Service registration and discovery
Circuit Breaker
Load balancing
Routing
Service-to-service calls
API Gateway
Distributed messaging

Example: Coordination Boiler Plate

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Netflix OSS

Netflix_logo

Eureka
Hystrix & Turbine
Ribbon
Feign
Zuul
Archaius
...

Example: Spring Cloud and Netflix

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Configuration Server

gears

Pluggable source
Git implementation
- Per service repos
SVN implementation
Versioned
Rollback-able
Configuration client
starts in bootstrap phase

DEMO

Discovery: Eureka

eureka

Service Registration Server
Highly Available
In AWS terms, multi Availability
Zone and Region aware

http://techblog.netflix.com/2012/09/eureka.html

DEMO

Client Side Load-balancing: Ribbon

ribbon

Client side load balancer
Pluggable
Round robin, random,
weighted response time

http://techblog.netflix.com/2013/01/announcing-ribbon-tying-netflix-mid.html

DEMO

Declarative Rest Client: Feign

Pluggable Codecs, Clients and Annotations
Aims to be simple
Creates a proxy from a Java interface

DEMO

Circuit Breaker Metrics

Via actuator /metrics
Server side event stream /hystrix.stream
- also via rabbitmq
Dashboard app via @EnableHystrixDashboard

DEMO

Spring Cloud Actuator

Spring Cloud Commons	Spring Cloud Netflix
`/env` (POST)	`/routes` (POST)
`/pause` (POST)	`/routes` (GET)
`/refresh` (POST)	`/hystrix.stream/**` (GET)
`/restart` (POST)
`/resume` (POST)

DEMO

Spring Cloud Bus

Distributed actuator
/bus/env and /bus/refresh actuator endpoints
uses Spring Cloud Stream!

DEMO

Spring Cloud Security

Enable Single Sign On (SSO) with an OAuth2 provider declared in external properties.

@EnableOAuth2Sso

Enable security using OAuth2 access tokens

@EnableOAuth2Resource

Spring Cloud Brixton

Milestones:

Spring Cloud Consul: Config, Discovery, Bus, Leader Election, Locks
Spring Cloud Zookeeper: Config, Discovery, Locks, Leader Election
Spring Cloud Sleuth distributed tracing

Previews, experiments or ideas (ie: no guarantees!)

Spring Cloud Etcd: Config, Discovery, Locks, Leader Election

Links

https://github.com/spring-cloud
http://spencer.gibb.us/preso/spring-cloud-dcjug-2015.html
https://github.com/spencergibb/oscon2015
https://github.com/spring-cloud-samples
http://blog.spring.io
Twitter: @spencerbgibb, @david_syer
Email: sgibb@pivotal.io, dsyer@pivotal.io

Rx Java

rx-logo

Reactive: push vs. pull
Functional
Composable
Return Observable from Spring MVC
Controller (soon)
API Gateway combining services

Rx Java Example

public static void hello(String... names) {
    Observable.from(names).subscribe(s -> {
            System.out.println("Hello " + s + "!");
    });
}

Sample functions:

map
flatMap
zip
take
merge
350+ operators!

http://techblog.netflix.com/2013/02/rxjava-netflix-api.html

Spring Restdocs

Programatically generated snippets from unit tests!
Hand write asciidoc docs including generated snippets

[source,http]
----
HTTP/1.1 200 OK
Content-Type: application/hal+json

{
  "_links" : {
    "users" : {
      "href" : "http://localhost:11070/users{?page,size,sort}",
      "templated" : true
    },
    "profile" : {
      "href" : "http://localhost:11070/alps"
    }
  }
}
----

https://github.com/spring-projects/spring-restdocs

Cloudfoundry

Environment Provisioning
On-Demand/Automatic Scaling
Failover/Resilience
Routing/Front-end Load Balancing
Monitoring

Deploying services needs to be simple and reproducible

$ cf push app.groovy

and you don't get much more convenient than that.

(Same argument for other PaaS solutions)

Micro vs Monolithic... is NOT new

From:         kt4@prism.gatech.EDU (Ken Thompson)
Subject:      Re: LINUX is obsolete
Date:         3 Feb 92 23:07:54 GMT
Organization: Georgia Institute of Technology

I would generally agree that microkernels are probably the wave
of the future. However, it is in my opinion easier to implement
a monolithic kernel. It is also easier for it to turn into a
mess in a hurry as it is modified.

Regards, Ken

mono-vs-micro-os

Spring Cloud

Example Distributed System: Minified

Features

Example: Coordination Boiler Plate

Netflix OSS

Example: Spring Cloud and Netflix

Configuration Server

Discovery: Eureka

Client Side Load-balancing: Ribbon

Declarative Rest Client: Feign

Circuit Breaker: Hystrix

Hystrix

Hystrix Fallback

Circuit Breaker Metrics

Routing: Zuul

How Netflix uses Zuul

Spring Cloud Actuator

Spring Cloud Bus

No soup for you!

Spring Cloud Sidecar

Spring Cloud Security

Spring Cloud Brixton

Links

Rx Java

Rx Java Example

Notes

Notes cont.

Spring Restdocs

Spring Session

Continuous Delivery

Cloudfoundry

Micro vs Monolithic... is NOT new

What's wrong with a monolith?