A RESTful MicroService for JSON Processing in the Database · 1. Load your JavaScript code in your...

Copyright © 2017, Oracle and/or its affiliates. All rights reserved. |

A RESTful MicroService for JSON Processing in the Database

Kuassi Mensah Director, Product Management Database Server Technologies July 11, 2017


Safe Harbor Statement

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, and timing of any features or functionality described for Oracle’s products remains at the sole discretion of Oracle.

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Speaker Bio

Confidential – Oracle Internal/Restricted/Highly Restricted 4

Director of Product Management at Oracle

• Java frameworks for the Oracle database (OJVM, JDBC, UCP, App Cont, TG, etc)

• Hadoop, Spark and Flink integration with the Oracle database

• JavaScript with Oracle database (Nashorn with JDK, JRE and OJVM)

MS CS from the Programming Institute of University of Paris VI (Jussieu)

Frequent speaker @ JavaOne, Oracle Open World, Data Summit, Node Summit, Collaborate/IOUG, RMOUG, BIWA , UKOUG, DOAG, OUGN, BGOUG, OUGF, OTN LAD, OTN APAC.

Author: Oracle Database Programming using Java and Web Services

Social network: @kmensah, http://db360.blogspot.com/, https://www.linkedin.com/in/kmensah


Program Agenda

The Evolution of Web Applications

Processing JSON in the Database

JavaScript MicroService on the Database tier

A RESTful JavaScript MicroService

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• Service-based architecture Death of the monolithic application. The era of microservices

• Programming models and languages Functional programming, Reactive programming Style trumps languages

• Data models, formats and persistence RDBMS, XML, JSON, Text, Spatial, Graph, etc Polyglot persistence

• Cloud Services Storage, Infrastructure, Software, Platform, Containers, etc


Micro Services


• Distributed Service-oriented architecture

• A Web Application may have of up to thousands of microservices

• Polyglot

• Isolation between services

• Loose coupling, communication over simple wire protocols


Monolithic Shopping Cart Application

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Source: http://blog.arungupta.me/monolithic-microservices-refactoring-javaee-applications/

Copyright © 2017, Oracle and/or its affiliates. All rights reserved. | 9

MicroService-based Shopping Cart Application Source: http://blog.arungupta.me/monolithic-microservices-refactoring-javaee-applications/


Key Benefits of Micro Services


• Organizational and cultural shift

• Each microservice is developed, deployed and tested independently

‒"you build, you run it“ (Amazon)

• DevOps, Continuous Integration and delivery

•Team agility, flexibility, scalability, fault tolerance

• Maintenance: detect failure fast, fail gracefully and recover fast

• But Increased complexity Network Congestion and latency

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Technology of MicroServices


• Containers: Docker, LXC, etc

• Service Registry & Discovery: Zookeeper, Eureka, OSGi, Kubernetes

• Eventing

• Distributed Consensus

• Elastic Infrastructure

• Messaging

• Polyglot: language, persistence, etc.


Polyglot Persistence with Oracle Database

The Oracle database furnishes an integrated access to all data models

• Relational

• XML

• JSON

• Text

• Graph

• Spatial

• Multimedia


Program Agenda





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Mission statement

• Design a service for processing millions of JSON documents stored in a database

• The service may be implemented in any language

• The service may be deployed in any tier (mid-tier, database)

Copyright © 2017, Oracle and/or its affiliates. All rights reserved. | Confidential – Oracle Internal/Restricted/Highly Restricted 15

Implementation Choices


Program Agenda





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JavaScript & Java: Top Two Popular Languages

http://redmonk.com/sogrady/2017/06/08/language-rankings-6-17/


JavaScript: a Language, a Platform, an Ecosystem

• Ubiquitous

• Tons of libraries, frameworks, and tools Node.js, Angular.js, Backbone.js, React.js, …, new frameworks by the day

• Versatile JavaScript supports all programming models, styles and applications types

• JavaScript extended thru other Languages http://bit.ly/1VpgaOl


JavaScript on the JVM: Nashorn

• Nashorn engine: replacement for Rhino https://blogs.oracle.com/nashorn/ https://wiki.openjdk.java.net/display/Nashorn/Nashorn+jsr223+engine+notes https://docs.oracle.com/javase/8/docs/technotes/guides/scripting/nashorn

• Preserves investment in Java thru interoperability

– Calling Javascript from Java

– Calling Java from JavaScript

• Built into Java 8

https://wiki.openjdk.java.net/display/Nashorn/Nashorn+jsr223+engine+notes

https://docs.oracle.com/javase/8/docs/technotes/guides/scripting/nashorn


Running JavaScript with Nashorn using javax.script

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// 1) Create an instance of the script engine manager

ScriptEngineManager factory = new ScriptEngineManager();

// 2) Create an instance of a Nashorn engine

ScriptEngine engine = factory.getEngineByName("javascript");

// 3) initialize your Java resource

URL url =

Thread.currentThread().getContextClassLoader().getResource(abFilePath);

// 4) evaluate the JavaScript code

engine.eval(new InputStreamReader(url.openStream()));

// 5) invoke the evaluated JavaScript function using invokeFunction

Invocable invobj = (Invocable) engine;

Object selectResult =

invobj.invokeFunction("selectQuery", inputId);


NASHORN

JDBC

NASHORN

Mid-tier (Java 8) DB 12.2 (Java 8)

JavaScript/Nashorn with Oracle Database


JavaScript In the Database

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• Why? - Faster, no network latency - Avoid data shipping i.e., processing thousands/millions of JSON documents in RDBMS - Reuse JavaScript code and skills for database modules

• Many DBMS(es) furnish JavaScript - MongoDb - Cosmos DB (built on DocumentDB) - ForerunnerDB

• Oracle database 12cR2 OJVM supports Java 8 and Nashorn


Java VM in Oracle RDBMS (a.k.a. OJVM) Same Isolation and Scalability as Microservice Containers

JDK8 VM (+ Nashorn) Class Objmems

Newspace

Oldspace

Sessionspace

Internspace

Database Process / Session (PGA)

Shared Memory (SGA)

Newspace

Oldspace

Sessionspace

Newspace

Oldspace

Sessionspace

User Java & JavaScript Classes


How to Run JavaScript In the Database

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1. Load your JavaScript code in your Schema as Java Resource loadjava –v –u yourschema hello.js

2. Invoke JavaScript : 3 approaches 1) JavaScript Procedures from SQL or PL/SQL by using dbms_javascript.run SQL: call dbms_javascript.run('hello.js'); PL/SQL: dbms_javascript.run('hello.js'); 2) JavaScript Procedures from Java in the database import oracle.aurora.rdbms.DbmsJavaScript;

…

DbmsJavaScript.run("hello.js");

3) JavaScript Functions: using the standard JSR223 scripting APIs in javax.script


A JavaScript MicroService for JSON Processing

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var selectQuery = function(id)

{

var Driver = Packages.oracle.jdbc.OracleDriver;

var oracleDriver = new Driver();

var url = "jdbc:default:connection:"; // server-side JDBC

var query ="SELECT first_name, last_name from employees";

// establish a JDBC connection

var connection = oracleDriver.defaultConnection();

// prepared statement

var preparedStatement = connection.prepareStatement(query);

// execute Query

var resultSet = preparedStatement.executeQuery();

while(resultSet.next()) {

// Placeholder for parsing & processing JSON

// Display results

print(resultSet.getString(1) + "== " +

resultSet.getString(2) + " " );

}

// cleanup objects

resultSet.close();preparedStatement.close();connection.close();

return output;

}


Invoking JavaScript in the Database with javax.script


create or replace and compile java source named "InvokeScript" as

mport javax.script.*;

import java.net.*;

import java.io.*;

public class InvokeScript {

public static String eval(String inputId) throws Exception {

String output = new String();

try {

// create a script engine manager

ScriptEngineManager factory = new ScriptEngineManager();

// create a JavaScript engine

ScriptEngine engine = factory.getEngineByName("javascript");

//read the script as a java resource

engine.eval(new

InputStreamReader(InvokeScript.class.getResourceAsStream("/select.js")));

Invocable invocable = (Invocable) engine;

Object selectResult = invocable.invokeFunction("selectQuery", inputId);

output = selectResult.toString();

} catch(Exception e) {

output =e.getMessage();

}

return output;

}

}

/


Invoking JavaScript Functions

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-- Wrap InvokeScript.eval() as a SQL Funtion

CREATE OR REPLACE FUNCTION scriptEval(inputId in varchar2)

return varchar2 as language java name

‘InvokeScript.eval(java.lang.String) return

java.lang.String';

/

-- A SQL Procedure for calling scriptEval

CREATE OR REPLACE PROCEDURE sqldemo(id IN varchar2) IS

output varchar2(10000);

BEGIN

SELECT scriptEval(id) INTO output from dual;

dbms_output.put_line(output);

END;

/


Invoke MicroService via SQL

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sqlplus ORDSTEST/ORDSTEST

SQL> set serveroutput on

SQL> call dbms_java.set_output(80000);

Call completed.

SQL> call sqldemo('100');

JavaScript MicroService

{ "EmpId" : "100", "FirstName" : "Kuassi", "LastName" : "Mensah", "Job" : "Manager", "Email" : "[email protected]", "Address" : { "City" : "Redwood", "Country" : "US" } }

JSON

JSON


Demo Invoking the JavaScript MicroService via SQL



Program Agenda




RESTful JavaScript MicroService

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RESTful JavaScript MicroService

Oracle Confidential – Internal/Restricted/Highly Restricted 31

REST framework

JSON

JSON JavaScript MicroService


Oracle REST Data Services (ORDS)

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• Runs on APEX Gateway, WLS, Tomcat, GlassFish, Jersey “Install Oracle REST Data Services 3.0.0 EA2 in under 5 minutes http://blog.cdivilly.com/2015/03/11/install-ords-3.0.0

• Need a USERS tablespace with at least 40MB space

• Follow the steps in “Installation Example” - accept defaults - skip APEX Gateway (pick option “2”) - skip “specify passwords for Application Express RESTful Services database users” (pick option “2”) - start in standalone mode (pick option “1”)

http://blog.cdivilly.com/2015/03/11/install-ords-3.0.0






ORDS Configuration

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• Configure the REST service for invoking JavaScript Microservices the URL is made of workspace + p_base_path + p_pattern http://server:port/ords/<workspace>/load/routes/nashorn/jsonqry/<n> begin ords.create_service( p_module_name => 'load.routes' , p_base_path => '/load/routes/', p_pattern => 'nashorn/selectbyid/:id', p_source_type => 'plsql/block', p_source => 'begin selectbyid(:id); end;‘ ); commit; end; /


RESTful MiroService for JSON Processing

{ "EmpId" : "100", "FirstName" : "Kuassi", "LastName" : "Mensah", "Job" : "Manager", "Email" : "[email protected]", "Address" : { "City" : "Redwood", "Country" : "US" } }

JSON

http://localhost:8090/ords/ordstest/load/routes/nashorn/selectbyid/100

Oracle REST Data Services

Db call

URI Request or HTTP(s) post mapped to SQL request

JDBC Connection

Pool

Oracle Database

URI http(s)

JSON

JavaScript MicroService


Demo Invoking the JavaScript MicroService via SQL



Resources

Oracle Confidential – Internal/Restricted/Highly Restricted 36

• GitHub Oracle Db Examples Nashorn https://github.com/oracle/oracle-db-examples/tree/master/javascript/nashorn

• JavaScript in Oracle Database 12c Release 2 http://db360.blogspot.de/2016/11/javascript-in-oracle-database-12c.html

• REST enable Java or JavaScript in the Database http://db360.blogspot.de/2016/11/rest-enable-java-or-javascript-in.html

• Tim Hall’s Oracle REST Data Service (ORDS) articles https://oracle-base.com/articles/misc/articles-misc#ords


Questions?

Confidential – Oracle Internal 37

A RESTful MicroService for JSON Processing in the Database · 1. Load your JavaScript code in your...

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