dotCloud,

use Perl;

What is dotCloud?

Platform as a ServiceComputing Platform

Solution Stack

Horizontally and vertically scalable

Sane defaults in a configurable platform.

Rapid deploymentFrom create to live in a couple of minutes.

Hot-patchingChanges can be pushed with zero-downtime.

Complexity and Reliability management.So you can sleep at night.

Why use a Cloud platform service?

Developers don't have to pretend to be system administrators.

Clients don't have to maintain an infrastructure or expand the IT department.

Start-ups don't have to waste limited funds on hardware and fiber into their garage.

Quickly and easily scale to meet popular demand.

Reliability, Availability.

Services

PerlPythonRubyNodeJSRedisMySQLPostgreSQLSSLWebSocketJavaPHPMongoDBStaticRabbitMQApacheSolrSMTPOpaCustom

dotCloud services

Service types includeWeb services (Served by nginx)Perl, Python, PHP, Ruby, Java, Opa, NodeJS (sans nginx), and static.

Worker services

Data servicesMySQL, PostgreSQL, MongoDB, redis.

Other servicesApache Solr, RabbitMQ, SSL, SMTP, WebSocket

Custom Stacks

Web/DatabasePerl

PostgreSQL

SSL

Redis

Select stack components to match the application's needs.

As many or as few as necessary.

A dotCloud stack...

Mix and match services as you see fit.We're here to talk about Perl.

Hosted on EC2.Scaled apps get multiple availability zones.

Stack components fit together like building blocks.

Add or remove components as the application evolves.

A typical Perl stack...

A Perl web service.Plack sits on nginx. Your framework sits on Plack.Catalyst, Dancer, Mojolicious, bare Plack... anything that can ride on Plack.

A database?MySQL, MongoDB, PostgreSQL, Redis.

Multiple if necessary.

A Perl Worker?Daemons, and long-running processes.

Custom webservers.Websocket support.

Maybe an SSL service with custom domain.

It's up to you, and you can change at any time.

Perl services...

Web or worker.

Perl web services spawn four processes.If a process dies it is re-spawned.

If an EC2 instance goes wonky dotCloud reboots it and restores from backup.

Scaled applications were not affected...

Perl worker service is for long-running services that don't need nginx/Plack.

What is Scaling?

HorizontalConcurrency Handle more requests.

Redundancy High availability.

Master/Slave Database Replication.

VerticalMemory Breathing room.

Storage Persistent data.

Processing More CPU.

Horizontal Scaling with dotCloud

Horizontal:Multiple Perl services under the same applicationMultiple EC2 availability zones: Automatic.

Load balancing: Automatic.

Failover: Automatic.

Dedicated cluster.

Multiple Database ServicesMultiple EC2 availability zones.

Replication: Automatic.

Failover and re-syncing: Automatic.

Vertical Scaling with dotCloud

Vertical scaling reserves more memory and storage.Scale memory in 32MB increments.

Storage is allocated as 10x the RAM allotment.

Examples:A Perl service that needs 256MB to breathe in, and 2GB storage: Scale to 256MB.

A database that needs 4GB storage: Scale to 416MB RAM.

CPU scaling isn't featured at this time.

What does it cost? Sandbox

Sandbox Applications FREE.dotCloud clearly wants to be friendly to developers.Non-scaled applications without custom domains are free.

RAM, availability, and bandwidth are on a best effort basis.

Piggyback SSL is free.

Develop for free.

Test for free.

Deploy and use for free.

No time limitations.

No limited introductory periods.

Even multi-service stacks are free.

PLAY, enjoy!

What does it cost? Live

When you need....Horizontal or vertical scaling.

Reliability and performance guarantees.

Custom domains.

CA-certificate SSL.

$4.32/month per service-instance per 32MB RAM.

Pricing Example

A Perl web service that needs 64MB RAM: $8.64/month.Four processes are spawned. An app consuming 16MB deploys in 64MB RAM after four workers spawn.

Horizontally scale that same service to two service-instances for reliability and load balancing: $17.28.

Add a horizontally scaled (master/slave) database with 640MB storage allocation: Total cost: $34.56/month.

More breathing room: Scale Perl to 128MB and database to 1GB storage: $69.12/month.

Scale as needed

Hit by a swarm?Up-scale to as many as five Perl service-instances (20 total processes).

Higher scaling levels are available by explicit arrangement.

Nobody clicks at night/weekends?Down-scale during low-volume times.

Usage is measured hourly.

Scaling adjustments are one liners with the CLI.

Nearly instant spin-up.

Getting started

Create an account

Download and configure the CLI$ sudo easy_install pip && sudo pip install dotcloudUbuntu required sudo apt-get install python-setuptools first... bleah!

Windows and MacOS versions also exist.

$ dotcloudEnter the API key from http://www.dotcloud.com/account/settings

Create an application

Set up a local application directory.$ mkdir myapp$ cd myapp

We'll use a Mojolicious Lite-App.$ mojo generate lite_app myapp

Plan, program,test, etc...

Initialize the dotCloud repo.$ dotcloud create myapp

Prepare the configuration files

Makefile.PL

PREREQ_PM => { Test::More=> '0', YAML => '0', Mojolicious=> '3.0', Plack => '0.9974', };

Configuration files

app.psgi$ENV{MOJO_MODE} = 'production'require 'myapp.pl';

dotcloud.ymlwww: type: perl

Deploy!

$ dotcloud push myapp myapp/dotcloud command name path

Deployment finished successfully. Your application is available at the following URLswww: http://myapp-daoswald.dotcloud.com/

What just happened?

Relevant files were uploaded.rsync mercurial, or git push.

You do have some control over this process if necessary:dotcloud push all

.gitignore

.dotcloudignore

cpanm pulls in all dependencies.

Application is built per Makefile.PL.

A supervisor starts Plack and spawns the workers.

Zero-downtime upgrades.

dotcloud.yml

List all the services.Give each a unique name.

List dependencies that don't fit Makefile.PL.cpanm used internally. Even pull tarballs by URL and build them out.

List an application root directory (per service)Useful for apps that reside in a more scalable directory structure.

Set environment variables.

Define prebuild and postbuild actions.

A simple directory structure

project_root/dotcloud.ymlapp_root/app.psgiMakefile.PLmyapp.plstatic/...

A more scalable directory structure

project_root/dotcloud.ymldatabase_init.sqlmyapp/app.psgiMakefile.PLmyapp.conflib/Model/MyApp.pmController/

log/public/script/myapp.pl

t/templates/

dotcloud.ymlwww:type: perlapproot: myappdb:type: mysql

app.psgi$ENV{MOJO_MODE} = 'production';require 'script/myapp.pl';

The database connection

dotcloud.yml:www: type: Perl approot: myappdb: type: mysql

environment.json Readable by the application.

Contains database host, port, login, password info, custom variables, etc.Inside my app, I merge its contents into my configuration data-structure.

$ dotcloud info myapp.dbView service parameters.

$ dotcloud run myapp.db mysqlGet a mysql> prompt.

environment.json

{ "DOTCLOUD_WWW_HTTP_URL": "http://myapp-daoswald.dotcloud.com/", "DOTCLOUD_WWW_SSH_PORT": "XXXXX", "DOTCLOUD_WWW_SSH_URL": "ssh://dotcloud@myapp-daoswald.dotcloud.com:XXXXX", "DOTCLOUD_DB_MYSQL_LOGIN": "XXXXXX", "DOTCLOUD_WWW_SSH_HOST": "myapp-daoswald.dotcloud.com", "DOTCLOUD_PROJECT": "myapp", "DOTCLOUD_SERVICE_NAME": "www", "DOTCLOUD_WWW_HTTP_VHOSTS_LIST": "myapp-daoswald.dotcloud.com", "PORT_SSH": XXXXX, "DOTCLOUD_DB_SSH_PORT": "XXXXX", "DOTCLOUD_WWW_HTTP_HOST": "myapp-daoswald.dotcloud.com", "DOTCLOUD_DB_SSH_URL": "ssh://mysql@myapp-daoswald.dotcloud.com:XXXXX", "DOTCLOUD_ENVIRONMENT": "default", "DOTCLOUD_DB_SSH_HOST": "myapp-daoswald.dotcloud.com", "DOTCLOUD_DB_MYSQL_HOST": "myapp-daoswald.dotcloud.com", "DOTCLOUD_DB_MYSQL_PASSWORD": "some_passphrase", "DOTCLOUD_DB_MYSQL_PORT": "XXXXX", "DOTCLOUD_DB_MYSQL_URL": "mysql://USER:PASS_XXXXX@myapp-daoswald.dotcloud.com:XXXXX", "DOTCLOUD_SERVICE_ID": "0", "PORT_HTTP": 80}

environment.json simplified

DotCloud::EnvironmentEasy handling of environment in dotcloud.(In case a simple JSON file isn't simple enough.)

Other dotcloud.yml options

www:type: perlapproot: helloperlrequirements:http://example.com/something/not/on/cpan/yet.tar.gz

config:perl_version: v5.16.xuwsgi_memory_report: trueuwsgi_buffer_size: 8192uwsgi_processes: 4

prebuild: ./prebuild.plpostbuild: ./postbuild.pl

worker:type: perl-worker

Odds and ends

Static content will be served out of static/

nginx.conf: override the default nginx configuration.

Crontabs may be set in the Perl service, in a separate worker service, even in a database service.Beware of horizontal scaling and crontabs.

Off-site backups scheduled via crontabs.

dotCloud is the first PaaS with WebSocket support.Mojolicious is also WebSocket friendly.

The CLI tool

$ dotcloud create myapp$ dotcloud create myapp -f live$ dotcloud info myapp.www$ dotcloud push myapp$ dotcloud stats myapp.www$ dotcloud scale myapp db:instances=2$ dotcloud scale myapp www:instances=4$ dotcloud scale myapp www:memory=512M$ dotcloud destroy myapp$ dotcloud logs myapp.www$ dotcloud run myapp.db -- single-command$ dotcloud ssh myapp.worker

A sample use-case

Client requires high availability web, and database redundancy:Perl web service scaled to two 256MB instances.Load balancing, automatic failover, separate availability zones.

4 processes of 64MB each per service instance.Enough for Mojolicious, DBIx::Class, Moose, and some breathing room.

Database scaled to two instances of 512MB (5GB storage).Replication/syncing, automatic failover, separate availability zones.

A single 64MB Perl worker for cron jobs (backups, etc.)

Cost: $216/month.

A custom domain with SSL certificate, add $21.60/month: total, $237.60.DotCloud configures a dedicated load balancer instance (since SSL requires at least one IP address per domain, or more accurately, per certificate).

Client and developer each get to sleep at night: Priceless.Sorry IT department nothing to see here. ;)

Communications

@dotcloudstatusExceptional events and are tweeted out.

Get used to Scaled applications were unaffected...

http://status.dotcloud.comThe same as the tweets.

http://platform-status.dotcloud.comA quick overview of cluster status.

$ dotcloud status myapp.www

irc://irc.freenode.net#dotcloud

support@dotcloud.comReal (useful) replies within a few hours No dialog script.

http://support.dotcloud.com

http://help.dotcloud.com

Conclusions

Much more than bare EC2.

Supportive of the developer community.

Can-do attitude.

Innovative.

Reliable.

It's easy.

Deploying an application takes minutes.

Hot-patches take seconds, with no downtime.

A Working Example

The Perl Regex Testerhttp://retester-daoswald.dotcloud.com

Uses a single dotCloud Perl service and less than 96MB RAM.Deployed as a Sandbox app.

Configured for two uwsgi processes (low volume, so conserve memory)

If deployed Live, it would cost abpit $13/month.

A Mojolicious::Lite application.

Includes the application script, a model module, Twitter Bootstrap CSS/JS.

Pulls in many CPAN dependencies (mostly to handle the paranoia of executing user-supplied regexes).

Source on Github: https://github.com/daoswald/retester.git

David Oswalddaoswald@gmail.comdavido@cpan.org

http://www.slideshare.net/daoswald/deploying-perl-apps-on-dotcloud

Experiment! Play!

$ dotcloud push my_cool_idea

Next month let's look at what you deployed to dotCloud.