Real-world #microservices

with Apache Camel and

Fabric8

Who?Christian Posta

Principal Middleware Specialist/Architect

Blog: http://christianposta.com/blog

Twitter: @christianposta

Email: christian@redhat.com

• Committer on Apache Camel, ActiveMQ, Fabric8, PMC on ActiveMQ

• Author: Essential Camel Components DZone Refcard

• Frequent blogger and speaker about open-source technology!

• Microservices

• Heavy lifting with Apache Camel

• Managing microservices with Fuse,

Fabric8 v1

• OpenShift, Fabric8 v2

• Beer (lots?)

Agenda

Why do we care?

Micro what?

• Services, reuse, composition

• Loose coupling!

• Contracts

• Incremental change

• “Business Agility”

SOA!

SOA made smaller… micro even…

So what are microservices?

A term that helps describe distributed systems

that organically evolve into scalable, loosely

coupled, modular sets of services that work

together to deliver business value

with acceptable tradeoffs.

So what are microservices?

• If my services are isolated at the

process level, I’m doing

#microservices

• If I use REST/Thrift/ProtoBuf

instead of SOAP, I’m doing

#microservices

• If I use JSON, I’m doing

#microservices

• If I use no-container / SpringBoot

/ Dropwizard / embedded Jetty,

I’m doing #microservices

I’m doing microservices if…

• Agile methodology

• SOA principles

• Domain Driven Design

• Hexagonal Architectures

• Pipes and Filters

• Actor Model

• REST

• SEDA

Microservices emerged as a result…

• Modularity!

• Flexible technology options

• “Smart endpoints” “dumb pipes”

• Evolving design

• Independently scalable

• Automation, DevOps philosophy

• Decentralized, choreographed interactions

• Testable

• Design for failure

Microservices…

Isolation: logical or physical?

• No silver bullet; distributed systems are

*hard*

• Dependency hell, custom shared libraries

• Fragmented and inconsistent management

• Team communication challenges

• Health checking, monitoring, liveness

• Over architecting, performance concerns,

things spiraling out of control fast

Challenges ahead…

Apache Camel for

microservices?

Real developers ride Camels!

2

2

Apache CamelApache Camel is an open-source,

light-weight, integration library.

Use Camel to integrate disparate systems

that speak different protocols and data formats

Apache Camel

Enterprise Integration Patterns

http://camel.apache.org/eip

Features

● Enterprise Integration Patterns (EIPs)

● Domain Specific Language to write “flows” or “routes”

● Large collection of adapters/components for legacy

systems, B2B, and SaaS

● Strong Unit test/Integration test framework

● Expression languages

● Data Formats

● Tooling with JBoss Developer Studio

Java DSLpublic class OrderProcessorRouteBuilder extends RouteBuilder {

@Override

public void configure() throws Exception {

from(“activemq:orders”)

.choice()

.when(header(“customer-rating”).isEqualTo(“gold”))

.to(“ibmmq:topic:specialCustomer”)

.otherwise()

.to(“ftp://user@host/orders/regularCustomers”)

.end()

.log(“received new order ${body.orderId}”)

.to(“ibatis:storeOrder?statementType=Insert”);

}

}

Spring XML DSL<route id=“processOrders”>

<from uri=“activemq:orders”/>

<choice>

<when>

<simple>${header.customer-rating} == ‘gold’</simple>

<to uri=“wmq:topic:specialCustomer”>

</when>

<otherwise>

<to uri=“ftp://user@host/orders/regularCustomers” />

</otherwise>

</choice>

<log message=“received new order ${body.orderId}”/>

<to uri=“ibatis:storeOrder?statementType=Insert”/>

</route>

Camel - JBoss Developer Studio

• Dynamic routing options

• REST DSL

• Backpressure mechanisms

• Loadbalancing algorithms / Circuit Breaker

pattern

Heavy Lifting: Camel for Microservices

• “Smart endpoints, dumb pipes”

• Endpoint does one thing well

• Metadata used for further routing

• Really “dynamic” with rules engine (eg,

Drools/BRMS)

Dynamic Routing

• Content Based Router

• Dynamic Router

• Routing Slip

• Recipient List

Dynamic Routing

• Expressive way to define REST endpoints

• POST, REST, PUT

• Auto binding to POJOs

• Plugs into Swagger for interface

definition/documentation

• Uses configurable HTTP engine• camel-netty-http

• camel-jetty

• camel-reslet

• camel-sevlet (deploy into other containers)

• camel-spark-rest

REST DSL (2.14)

REST DSLpublic class OrderProcessorRouteBuilder extends RouteBuilder {

@Override

public void configure() throws Exception {

rest().post(“/order/socks”)

.description(“New Order for pair of socks”)

.consumes(“application/json”)

.route()

.to(“activemq:topic:newOrder”)

.log(“received new order ${body.orderId}”)

.to(“ibatis:storeOrder?statementType=Insert”);

}

}

• Backpressure is a way for a service to flow

control callers

• Detecting when can be difficult

• Need to bound processing queues in a

SEDA

• Take advantage of built in TCP flow control

for socket/http requests

Backpressure with Camel

• Throttle EIP• http://camel.apache.org/throttler.html

• Blocking SEDA Queue

• from(“seda:name?size=100&blockWhenFull=true)

• Configure jetty/netty to use blocking acceptor

queues

• https://wiki.eclipse.org/Jetty/Howto/High_Load

• Using Exception handling/retry and DLQ

logic when getting flow controlled• http://camel.apache.org/error-handling-in-camel.html

Backpressure with Camel

• Useful to keep from overloading a system

(use in conjunction with backpressure if you

can)

• Smart loadbalancing• Sticky

• Random

• Failover

• Circuit breaker

Loadbalance/Circuit breaker

Circuit breaker

Image from http://martinfowler.com/bliki/CircuitBreaker.html

Circuit breakerpublic class OrderProcessorRouteBuilder extends RouteBuilder {

@Override

public void configure() throws Exception {

from(“direct:someinterface”)

.loadbalance()

.circuitBreaker(3, 20000L, MyException.class)

.to(“ibatis:storeOrder?statementType=Insert”);

}

}

More Information● Camel in Action

● Apache Camel Developer’s Cookbook

● Community website

○ http://camel.apache.org/

JBoss Fuse (Red Hat

product)

RED HAT JBOSS FUSE

Development and tooling

Develop, test, debug, refine,

deploy

JBoss Developer Studio

Web services frameworkWeb services standards, SOAP,

XML/HTTP, RESTful HTTP

Integration frameworkTransformation, mediation, enterprise

integration patterns

Management and

monitoring

System and web services metrics,

automated discovery, container

status, automatic updates

JBoss Operations Network

+

JBoss Fabric Management

Console

(hawtio)

Apache CXF Apache Camel

Reliable MessagingJMS/STOMP/NMS/MQTT, publishing-subscribe/point-2-point, store and forward

Apache ActiveMQ

ContainerLife cycle management, resource management, dynamic deployment,

security and provisioning

Apache Karaf + Fuse Fabric

RED HAT ENTERPRISE LINUXWindows, UNIX, and other Linux

Managing microservice

deployments

• Simplifies deployments

• Provides centralized configuration

• Versioning

• Visualization of your middleware

• Service discovery

• Smart load balancing

• Failover

• Provides cluster capabilities, coordination

http://fabric8.io

• Implemented with Zookeeper and git

• Intended to be used with a dynamic

JVM/Apache Karaf

• Profiles store configuration, metadata, end-

state deployments

• Networking, JVM isolation, orchestration,

auto-scaling, health checks, cloud

deployments: all up to you

Fabric8 V1.x

• Registry• Where configs are stored, everything centrally

managed

• Profiles• Description of end-state deployment of a server

• Agent

• Listens on the server that can respond to registry

changes/profile updates

Fabric8 V1.x

Quick Demo V1

• Implemented with Docker and Kubernetes

• Use any JVM (or any technology)

• Docker images, encourage static, well-

defined, well-tested deployments

• Provides networking, JVM isolation,

orchestration, auto-scaling, health checks,

cloud deployments

• Still in community! Proving this out!

Fabric8 V2

Docker / Linux Containers

How different than VMs?

Kubernetes

• Pods

• Services

• Replication Controllers

Kubernetes

Red Hat’s PaaS: OpenShift

Public

PaaS

Service

On-premise

or Private

PaaS

Software

Open

Source

PaaS

Project

Scale IT Like a Factory with PaaS

Quick Demo V2

Demo and Questions