Nonblocking Database Access in Helidon SE

Copyright © 2019 Oracle and/or its affiliates.
Nonblocking Database Access
in Helidon SE
Oracle
September 16, 2019
Dmitry Kornilov /Tomas Langer

The following is intended to outline our general product direction. It is intended for information purposes only,
and may not be incorporated into any contract. It is not a commitment to deliver any material, code, or
functionality, and should not be relied upon in making purchasing decisions.The development, release,
timing, and pricing of any features or functionality described for Oracle’s products may change and remains at
the sole discretion of Oracle Corporation.
Statements in this presentation relating to Oracle’s future plans, expectations, beliefs, intentions and prospects
are “forward-looking statements” and are subject to material risks and uncertainties. A detailed discussion of
these factors and other risks that affect our business is contained in Oracle’s Securities and Exchange
Commission (SEC) filings, including our most recent reports on Form 10-K and Form 10-Q under the heading
“Risk Factors.”These filings are available on the SEC’s website or on Oracle’s website
at http://www.oracle.com/investor. All information in this presentation is current as of September 2019 and
Oracle undertakes no duty to update any statement in light of new information or future events.
Safe Harbor

Dmitry Kornilov
Senior Product Development Manager
Oracle

Tomas Langer
Helidon Architect
Oracle

• Introduction to Helidon
• Helidon DB Client
• Demo
• Q & A
Agenda

Helidon Introduction

Helidon (Χελιδόνι) = Swallow (Greek)

A set of Java libraries
for developing microservices

Project Helidon
• Open
• Innovative
• Support standards
• Supported active project

Open Source
• Hosted on GitHub
• https://github.com/oracle/helidon
• Apache 2.0 License

Supported Active Project
• Open Source support
• Web Site with guides and tutorials: https://helidon.io
• Public Slack channel: https://helidon.slack.com
• GitHub issues tracker: https://github.com/oracle/helidon/issues
• Management has committed to commercial support of Helidon
• AnyWebLogic licensed customer is automatically supported for
Helidon use

Landscape

• Microframework
• Tiny Footprint
• Functional style
• Reactive
• Transparent
• MicroProfile 3.0
• Small Footprint
• Declarative style
• Dependency Injection
• CDI, JAX-RS, JSON-P/B

Routing routing =
Routing.builder()
.get("/hello", (req, res) ->
res.send("Hello World"))
.build();
WebServer.create(routing)
.start();
@Path("hello")
public class HelloWorld {
@GET
public String hello() {
return "Hello World";
}
}

Helidon SE Components
Reactive Web
Server
Config
Security Tracing
Metrics
Health Check gRPC
MP
MP
MP
MP
MP
MP
Helidon DB Client

Helidon DB Client

Database access in Helidon SE
• Without Helidon DB Client...
• JDBC and most no-SQL drivers are blocking
• Backpressure implementation is complicated
• Support for tracing, metrics and health has to be programmed
• Configuration specific for each driver

Helidon DB Client – Reactive
• Non-blocking
• "native" if supported by driver (MongoDb, Cassandra and Redis have
reactive driver!)
• Using an executor service when wrapping a blocking driver (e.g. JDBC)
• Flow API
• Uses Flow.Publisher and Flow.Subscriber to process streams of data
• Backpressure
• records are read from the database only when requested by consumer
• in Helidon, this is propagated all the way to theTCP layer

Helidon DB Client - Observable
• Implemented as configurable interceptors
• all, or named statements ("select-all"), or statements by type (Insert,
Update, Delete...)
• either in a builder, or in configuration file
• Tracing
• Adds a trace to OpenTracing
• Metrics
• Counter, Meter,Timer
• Health
• "ping" operation for liveliness health check

Helidon DB Client - Configurable
• Statements in configuration
• All statements are named (including ad-hoc)
• Does not define a new query language
• Simple to modify a statement when needed
• Metrics, Health Checks in configuration
• Connectivity and database type in configuration
• Simple to switch to a different database

Helidon DB Client - Databases
• JDBC
• Using standard JDBC APIs, so any JDBC driver will work
• Support for local transactions
• MongoDB
• Using reactive MongoDB driver
• Basic operations usable for relational and other types of DBs
• CRUD operations

Helidon DB Client Configuration
# JDBC - MySQL
db:
source: "jdbc"
url: "jdbc:mysql://127.0.0.1:3306/pokemon?useSSL=false"
statements:
insert-mon: "INSERT INTO pokemons VALUES(:name, :type)"
# Mongo database:
db:
source: "mongoDb"
url: "mongodb://127.0.0.1:27017/pokemon"
statements:
insert-mon: '{"collection": "pokemons",
"value": {"_id": $name, "type": $type}}'

Helidon DB Client Usage
DbClient dbClient = DbClient.create(config.get("db"));
//...
private void insertPokemon(ServerResponse response, Pokemon pokemon) {
dbClient.execute(exec -> exec
.createNamedInsert("insert-mon")
.namedParam(pokemon)
.execute())
.thenAccept(count -> response.send("Inserted: " + count + " values"))
.exceptionally(throwable -> sendError(throwable, response));
}

Demo

Demo
Branch on Helidon: 581-helidon-db
https://github.com/oracle/helidon/tree/581-helidon-db

Q & A

Helidon-related Sessions on CodeOne 2019
Monday, Sep 16
01:30 PM - 02:15 PM
Helidon Flies Faster on GraalVM
Moscone South - Room 203
05:00 PM - 07:00 PM Hands on Lab: Building Microservices
with Helidon
MosconeWest - Room 3024B
Thursday, Sep 19
09:00 AM - 09:45 AM Helidon MicroProfile: Managing
Persistence with JPA
12:15 PM - 01:00 PM Migrating a Single Monolithic
Application to Microservices

Helidon-related Sessions on OOW 2019
Tuesday, Sep 17
02:00 PM - 02:20 PM
Building Helidon Applications
The Exchange (Moscone South) -Theater 4
Wednesday, Sep 18
09:00 AM - 09:45 AM BuildingCloud Native Applications with
Helidon

Thank You
Helidon Team
September 16, 2019
Dmitry Kornilov /Tomas Langer

Nonblocking Database Access in Helidon SE

More Related Content

What's hot (20)

Similar to Nonblocking Database Access in Helidon SE (20)

More from Dmitry Kornilov (18)

Recently uploaded (20)

Nonblocking Database Access in Helidon SE