A Solid Backend for a Solid Mobile Application

© 2013 The Qt Company

A Solid Back End for a Solid Qt Mobile Application


About Me


Lauri Nevala

• Over ten years of experience in creating web and mobile based applications

• Working in Qt Cloud Services team at The Qt Company

nevalau nevalla nevalla


Awesome mobile applications…


…and they all need back-end systems!


How do you implement your back end solution?


You have an idea

BUY AND SETUP HARDWARE

INSTALL OS

DEFINE ACCESSCONTROL

SETUP ANALYTICS

INSTALL SOFTWARE

BUILD

JUST START BUILDING

APP APP

X


PaaSPlatform as a Serv ice


What is PaaS?Applica'on*

Data*

Run'me*

Middleware*

OS*

Virtualiza'on*

Servers*

Storage*

Networking*

On#Premises#Yo

u*Manage*

Applica'on*

Data*

Run'me*

Middleware*

OS*

Virtualiza'on*

Servers*

Storage*

Networking*

IaaS$

You*Manage*

Vend

or*Provide

s*

Applica'on*

Data*

Run'me*

Middleware*

OS*

Virtualiza'on*

Servers*

Storage*

Networking*

PaaS$

You*Manage*

Vend

or*Provide

s*

Applica'on*

Data*

Run'me*

Middleware*

OS*

Virtualiza'on*

Servers*

Storage*

Networking*

SaaS#

Vend

or*Provide

s*

With PaaS, developer can focus just on building great apps. No need to worry about servers, operating system, loadbalancing, network or infrastructure.


Illustra(on by Rouge Group

PaaS


– Yefim Natis, Gartner

“We believe PaaS will enable organizations become more agile and responsive”

“Organizations who are late, don't adopt PaaS will fall behind”


Modern Application Development

1. Mobile First Approach - Factoring applications into many apps.

2. Cloud-Backed - Adopting more abstract and machine-independent application models for back ends in the form of PaaS.

3. Agile Teams - Rapid iterations, frequent releases, integration of users

4. Continuously Integrated and Delivered - No downtimes

5. DevOps-Enabled - Developers own deployments

6. User Experience-Centric - Focusing on the design and appearance of the application

7. Service Oriented Architecture - Use of micro services to compose application

8. Lightweight - Less complex software that is less time-consuming to install, learn and use

9. Socially Oriented - UX patterns from social networks (timelines, event streams etc), Data is updated using event-based push-oriented patterns. Integrated search functionality.

10.API Factored and Surfaced - Componentize and granularize back-end software in order to achieve composable and easy-to-evolve back-end platforms.



Managed Application Runtime (MAR)

Scalable, Multi-language, Multi-database,

Application Platform as a Service


Supported Frameworks

Supported frameworks by 3rd party build packs

Scala, Clojure, Play, Gradle, Grails, PHP, Go, Meteorite, Perl, Dart, Nginx, Apache, Jekyll


Built-In Services


Add Ons

Enginio Data Storage (EDS)

Managed WebSocket (MWS)


Enginio Data Storage (EDS)

Flexible and powerful cloud data storage

with built-in user and data access control


Managed WebSocket (MWS)

Fully managed service implementing a bi-

directional, real-time communication gateway

for WebSockets.


Developer Friendly Deployment

Deploy using Git – the most common VCS among developers

> git push qtc master


Scalable Architecture

Red

isM

ongo

DB

Mon

goD

B

Your Application Built-‐InServices

Applica2on Instances End Users

Configure

Deploy

Scale With Your Business

Git

Push

API

Red

isM

ySQ

L

Envi

ronm

ent V

aria

bles

Load

Bal

ance

r

myawesome.com

Scaling


Web Console


Command Line Tool


I Have an Idea

$$$


Mobile application that shows tweets in real

time


Back End

• DB where to store tweets

• Worker that retrieves/receives tweets from Twitter

• API that offers tweets to client app

• WebSocket server that push new tweets to client app


• Enginio Data Storage

+ Schemaless

+ REST API

Database


WebSocket Server• Managed WebSocket

+ Easy to start

+ REST API


Worker + API• Managed Application Runtime

+ PaaS

+ Just build the app


1. get initial tweets

2. new tweet

3. save tweet

4. send WebSocket message


Worker - Rubyrequire 'tweetstream' require 'qtc-‐sdk' !TweetStream.configure do |config| config.consumer_key = ENV['CONSUMER_KEY'] config.consumer_secret = ENV['CONSUMER_SECRET'] config.oauth_token = ENV['OAUTH_TOKEN'] config.oauth_token_secret = ENV['OAUTH_SECRET'] config.auth_method = :oauth end

eds = Qtc::Eds::Client.new(ENV['EDS_BACKEND_ID']) mws = Qtc::Mws::Client.new(ENV['MWS_GATEWAY_ID'], {access_token: ENV['MWS_SECURITY_TOKEN']}) tweets = eds.collection('tweets')

daemon = TweetStream::Daemon.new('tracker', :multiple => true, :no_pidfiles => true) daemon.track('#QtDD14') do |status| if !status.text.start_with?('RT @') tweet = { created: status.created_at, tweet_id: status.id, text: status.text, name: status.user.name, screen_name: status.user.screen_name, profile_img_url: status.user.profile_image_uri, hashtags: status.hashtags.map{|h| h.text.downcase } } tweets.insert(tweet) mws.send_message(tweet.to_json, {sockets: nil, tags: ['QtDD14']}) end end


API - Ruby / Sinatrarequire 'sinatra' require 'qtc-‐sdk' !set :port, ENV['PORT']

get '/tweets/:hashtag' do eds = Qtc::Eds::Client.new(ENV['EDS_BACKEND_ID']) tweets = eds.collection('tweets') query = { :q => { 'hashtags' => {'$in' => [params[:hashtag]] } }, :limit => 50, :sort => [{"sortBy" => "createdAt","direction" => "desc"}] } content_type :json, 'charset' => 'utf-‐8' result = tweets.find(query) result.to_json end

get '/websocket_uri' do mws = Qtc::Mws::Client.new(ENV['MWS_GATEWAY_ID'], {access_token: ENV['MWS_SECURITY_TOKEN']}) socket = mws.create_socket(["QtDD14"]) content_type :json,'charset' => 'utf-‐8' socket.to_json end


Procfile

• When using most common frameworks, MAR can automatically detect the executable.

• You can explicitly declare what can be executed in a Procfile.

• Each line declares a process type - a command that can be executed from your built application

worker: ruby ./worker.rb run web: rackup -‐p $PORT -‐E production


> git push qtc master


lanevala@it-‐l-‐m0015 ~/projects/qtdd-‐twitter-‐stream[master*]$ git push qtc master Counting objects: 9, done. Delta compression using up to 8 threads. Compressing objects: 100% (8/8), done. Writing objects: 100% (9/9), 1.46 KiB | 0 bytes/s, done. Total 9 (delta 6), reused 0 (delta 0) -‐-‐-‐-‐-‐> Ruby app detected -‐-‐-‐-‐-‐> Compiling Ruby/Rack -‐-‐-‐-‐-‐> Using Ruby version: ruby-‐2.1.2 -‐-‐-‐-‐-‐> Installing dependencies using 1.6.3 Running: bundle install -‐-‐without development:test -‐-‐path vendor/bundle -‐-‐binstubs vendor/bundle/bin -‐j4 -‐-‐deployment Fetching gem metadata from https://rubygems.org/........ Using eventmachine 1.0.3 Using json 1.8.1 Using thread_safe 0.3.4 Using multi_json 1.10.1 Using naught 1.0.0 Using rack 1.5.2 Using bundler 1.6.3 Using em-‐socksify 0.3.0 Using http 0.6.1 Using faraday 0.9.0 Using em-‐twitter 0.3.3 Installing httpclient 2.5.2 Installing inifile 3.0.0 Using memoizable 0.4.2 Using puma 2.9.1 Using rails_12factor 0.0.3 Using em-‐http-‐request 1.1.2 Using twitter 5.11.0 Using sinatra 1.4.5 Using tweetstream 2.6.1 Installing faye-‐websocket 0.7.5 Using qtc-‐sdk 0.0.5 from https://github.com/nevalla/qtc-‐sdk-‐ruby.git (at master) Your bundle is complete! Gems in the groups development and test were not installed. It was installed into ./vendor/bundle Bundle completed (9.04s) Cleaning up the bundler cache. Removing httpclient (2.4.0) Removing qtc-‐sdk-‐ruby (8e7a9e3858e8) -‐-‐-‐-‐-‐> Discovering process types Procfile declares types -‐> worker, web Default process types for Ruby -‐> rake, console, web -‐-‐-‐-‐-‐> Compiled slug size is 17M -‐-‐-‐-‐-‐> Deploying app Uploading app container .. done. mar-‐eu-‐1-‐13viqrf8 deployed to http://mar-‐eu-‐1-‐13viqrf8.qtcloudapp.com To git@git-‐mar-‐eu-‐1.qtc.io:mar-‐eu-‐1-‐13viqrf8 36e9190..b237ec8 master -‐> master lanevala@it-‐l-‐m0015 ~/projects/qtdd-‐twitter-‐stream[master*]$


Demo


Buildpacks

• When you deploy your Application, MAR slug compiler uses buildpack to prepares your code for execution.

• Each programming language and framework support is implemented as buildpack.

• Buildpack script will build the runtime environment on top of the Stack Image, a mini Linux distribution, and install everything that is needed.


• Stack Image is a mini Linux distribution which defines the core operating system and runtime environment. MAR Stack Images are based on following Linux distributions:

• Lucid based on Ubuntu 10.04 LTS Lucid Lynx

• Trusty based on Ubuntu 14.04 LTS Trusty Tahr will be available soon!


How to scale the application?

• MAR application processes can be scaled up or down dynamically.

• A typical web application has at least web process type declared in Procfile.

• You can set wanted concurrency level for process by issuing scale command using qtc-cli:


$ qtc-cli mar scale web=2

$ qtc-cli mar scale worker=4

$ qtc-cli mar scale worker=0


Configuration Variables

• When developing server-side applications, it is very often required to have a configuration for application that is varying between environments. For example staging, production, testing, etc.

• Configuration to some external systems like database addresses, credentials or other environment variables might be required.


• This configuration data is not included in your application code and can be changed independently.

• The configuration is exposed to a running application via environment variables.

• You can manage environment variables using the qtc-cli command line tool:

• qtc-cli mar envs:set SECRET_CODE=donotsharethis


Ports

Applicationinstances Load Balancer Client

ApplicationGET your-mar-address/index.html:80GET /index.html:47435

GET /index.html:47487


Logging

• Logs are a stream of time-ordered events aggregated from the output streams of all your application instance processes.

• MAR logger routes log streams from all these sources into single stream.

• Anything written to standard out (stdout) or standard error (stderr) is captured into application instance logs.


• Qt/C++: qDebug() << "Log me to stdout”;

• QML & Node.js: console.log("Log me to stdout”);

• Ruby: puts "Log me to stdout”

!

• $ qtc-cli mar logs


Qt Backend

• Qt support is activated when application has one or more qmake project files in the root folder.

• If you set QMAKE_ARGS environment variable it will be passed to qmake command

• You must specify web process manually in Procfile:

• web: ./hello-world/server --port $PORT


Supported Qt Versions• New applications will default to the latest stable version of Qt (currently

5.3.2).

• You can specify any supported Qt runtime version to be used to run your application. This functionality is enabled when your project has .qt_runtime file.

• Available Qt runtimes:

• qt-5.3.0

• qt-5.3.1

• qt-5.3.2

• qt-5.4.0-beta



Further Actions

• Visit qtcloudservices.com

• Sign-up

• Use it

• Give us feedback

• Qt forum

• [email protected]

http://qtcloudservices.com

mailto:[email protected]


Thank you!

http://www.qtcloudservices.com

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A Solid Backend for a Solid Mobile Application