Emily Jiang, WebSphere Application Server, CDI Development Lead, IBM Cloud @emilyfhjiang While there are likely a dozen or more Java-based microservice / cloud native initiatives in the industry, Eclipse MicroProfile provides a platform for Java developers to collaborate and innovate on areas of common interest. This BOF will give a short overview of MicroProfile and how it plans to optimize microservices for Enterprise Java, followed by a short Q&A to answer any clarifying questions, and the remainder of the time spent on collaborating to prioritize features for the next release. While MicroProfile's first release is founded in Java EE (CDI + JSON-P + JAX-RS), it is not intended to remain a subset of Java EE 7 (or 8). The intent is to collaborate and innovate as a community in the context of a microservices architecture across the 5 (and growing) MicroProfile implementations today. The end goal of MicroProfile is to feed the Java Community Process (JCP) with JSR submissions backed by well-thought-out concepts and even implementations that developers and enterprises can rely on. Come collaborate with your fellow MicroProfilers to move Enterprise Java microservices forward.

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Optimizing Enterprise Java
for a Microservices Architecture
John Clingan, middle-aged Java EE guy and MicroProfile-r
Emily Jiang, totally awesome MicroProfile engineer
Eclipse

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Agenda
MicroProfile Overview (~10 Minutes)
Example Specs - From concept to implementation (10 minutes)
Collaborate (Until they kick us out or we want to go for a beer)

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Enterprise Java Standards History

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What is MicroProfile?
A community of individuals, organizations, and vendors …
… collaborating within an open source (Eclipse) project ….
… to bring microservices to the Enterprise Java
community

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Innovation vs Standardization
(Open Source) Project Focused Standard (JSR) focused
(Java EE)(MicroProfile)

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Innovation vs Standardization
(Open Source) Project Focused Standard (JSR) focused
(Java EE)
Large multi-feature releasesIncremental feature release
(MicroProfile)

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Innovation vs Standardization
Spec Lead controls pace
(Open Source) Project Focused Standard (JSR) focused
(Java EE)
Large multi-feature releasesIncremental feature release
(MicroProfile)
Community controls pace

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Accelerating* Adoption of MicroServices
2016 2017 2018 2019
8 9
1.0
1.1
1.2
1.3
1.4
2020
1.5
* 2-4 releases per year

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MicroProfile 1.0 (Sep, 2016)
Contexts and Dependency Injection (CDI 1.1)
+
Java API for RESTful Web Services (JAX-RS 2.0)
+
Java API for JSON Processing (JSON-P 1.0)

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MicroProfile 1.1 Underway
Security: JWT Token Exchange 1.0
Health Check 1.0
Configuration 1.0
Fault Tolerance 1.0 (Stretch goal)
Second Quarter
2017!

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Will MicroProfile Features be in Java EE?
Possibly

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MicroProfile Java Programming Model
(In Progress)
● Config
● Fault Tolerance
● Health Checker
● Metrics
● Security

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Configuration
● Discussed with a formal proposal in the MicroProfile mailing list
(https://groups.google.com/forum/#!topic/microprofile/VJEEAOsVj
5E[26-50])
● After the proposal was accepted, a repository was created to
draft APIs/SPIs (https://github.com/eclipse/microprofile-config/)

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MicroProfile Java Prog. Model - Configuration

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MicroProfile Java Prog. Model - Configuration
Using CDI Injection
@Inject Config config; Inject all config properties that the class
can see
@Inject
@ConfigProperty(name=“myProp”
defaultValue=“blah”)
String prop1;
Inject the value of the property called
“myProp”. The value of prop1 will not be
refreshed. Suitable for static properties
and used on the RequestScoped beans.
@Inject
@ConfigProperty(name=“myProp”
defaultValue=“blah”)
Provider<String> prop1
Inject the value of the property called
“myProp” and it picks up the dynamic
changes.

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MicroProfile Java Prog. Model - Configuration
Programmatic lookup
ConfigProvider.getConfig(); The config object containing all
properties that the class owner can
see.
ConfigProvider.getBuilder()
.addDefaultSources()
.withSources(…).build();
Create a custom config object

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MicroProfile Java Prog. Model - Configuration
● The property file, microprofile-config.properties, packaged in the application can be
overwritten by :
○ System variables (400 as the default priority)
○ Environment variables (300 as the default priority) or
○ a custom property files with a higher priority than microprofile-config.properties
(100 as the default priority).

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MicroProfile Java Prog. Model - config
● Plan to finalise the current APIs/SPIs and release the Config 1.0
by mid April
● Then work on the new features of Config 1.1
● Join in the Config discussion
● Join in the Config hangout – on Thursdays

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MicroProfile Java Prog model –
Fault Tolerance
● Proposal discussion:
https://groups.google.com/forum/#!topic/microprofile/ESs9L3z08o
A
● Prototype (inspired by Failsafe): https://github.com/Emily-
Jiang/microprofile-faultTolerance-incubation

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MicroProfile Java Prog model –
Fault Tolerance
Retry The request should have a retry to recover from temporary
glitches
Fallback The request should have a fallback operation if retry fails
Timeout The request must have a timeout, to prevent from waiting
indefinitely
Circuit Breaker The request must prevent from repeating timeouts
Bulkhead One part of application failure must not bring the whole
application down

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Fault Tolerance - Fallback Retry
Set up retry policy and wrap the call with the policy and specify
the fallback operation
FaultToleranceFactory.getFaultToleranceType(RetryPolicy.class);
Duration delay = Duration.ofSeconds(1);
retryPolicy =
retryPolicy.retryOn(Exception.class).withDelay(delay)
.withMaxRetries(3);
Runnable fallbackService = () -> serviceB();
executor.with(retryPolicy).withFallback(fallbackService)
.run(mainService);

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Fault Tolerance - Circuit Breaker Timeout
Fail-fast, temporarily disable the running of a service
circuitBreaker =
FaultToleranceFactory.getFaultToleranceType(CircuitBreaker.class);
circuitBreaker =
circuitBreaker.withTimeout(timeout).withFailureThreshold(3)
.withSuccessThreshold(2)
.withDelay(delay);
Callable<Object> mainService = () -> serviceA();
Executor executor =
FaultToleranceFactory.getFaultToleranceType(Executor.class);
executor.with(circuitBreaker).get(mainService);

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Fault Tolerance - Bulkhead
Limit the number of concurrent calls to a service
ThreadPoolExecutor tpexecutor = new ThreadPoolExecutor(
poolSize, poolSize, 0,
TimeUnit.SECONDS,
new ArrayBlockingQueue<Runnable>(10));
bulkhead = bulkhead.withThread(tpexecutor);
executor.with(bulkhead) .run(mainService);

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MicroProfile Java Prog model –
Fault Tolerance
● Non-CDI approach was left out of the first release but focus on CDI-first
approach
● Discussion the CDI-first approach ongoing
● Use Interceptor to apply policy and use annotation to config policy

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Health Check, Metrics, Security
● Health Check – proposal accepted
● Metrics and Security – proposal in discussion

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Join the Community!

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Resources
MicroProfile.io
MicroProfile Discussion Forum
bit.ly/MicroProfileForum
MicroProfile Examples
https://github.com/microprofile/microprofile-samples