X fact to scale out

From delivering plugins to delivering "as a Service", some advices to run it easilyQuentin ADAM atAtlassian connect week 2017@waxzce2013

Quentin ADAM from the Clever Cloud@waxzce on twitter github- soundcloud instagram .Who am I ?

My day to day work : Clever Cloud, the IT automation company

Keep your apps online. made with node.js, scala, java, ruby, php, python, go

Cloud & on premise ;-)

And learn a lot of things about your code, apps, and good/bad design

Give back to the community

NEVER GONNA LET YOU DOWNclever-cloud.com

From shipping jar to operate a service

When you need to scaleThere are 2 ways

Growing and growing until you explode or become weird

Or split the work and make your software work as a team

Build an army of fat appYou can do both

So we need to be able to dispatch the workScale outMany workers doing the same thingNo SPOFGrowing is more easyIntroduce best practice

Scale up1 Fat instance1 Fat applicationSPOF (single point of failure)Hard to maintainAlways has a limitShort term meaningBest long term solution

If you only scale up, you gonna have a bad time

So, how to scale out ?Just some facts

Split process and storage

Picking one instance or another doesnt matterStatelessness is the key

Consider more things as dataUser accountUsers dataFilesSessionsEvents

Understand what is provided

Trust your middleware

Use an event broker to modularize your app

Use an event broker to modularize your appAMQPCelery 0MQRedisJMSEven some http chunk or websocketSome case : hadoop, akka

My talk about rabbitMQ: https://www.youtube.com/watch?v=15mzY2MfDgM&t=3s

My talk about rabbitMQ: https://www.youtube.com/watch?v=15mzY2MfDgM&t=3s Cron + FS is neither an event queue nor a job scheduler

Big change in software industryOne instance One organizationOne data repositoryOne instance (distributed)Multiple organization + a lot of usersOne data repository

YestedayNowMulti-tenant

Its a big impact on data management23

Instance for one OrganizationTake advantage of ACID database

But it designs a bottleneck

Example : e-shop on classic mode

Example : e-shop on classic modeUser A buy a hdd

Database Transaction :Stock managementOrder managementInvoice generationCustomer Account rewardTransaction user A is processed Stock & Order are just perfectly synchronize

Example : e-shop on classic modeUser A buy a hdd

Database Transaction :Stock managementOrder managementInvoice generationCustomer Account rewardTransaction user A is processed Stock & Order are just perfectly synchronizeUser B buy a hddTransaction user B is processed then

Example : e-shop on multi-tenant modei.e. : Multiple shop of various sellers on the same instance

Example : e-shop on multi-tenant modeUser A buy a hdd on seller A

Database Transaction :Stock managementOrder managementInvoice generationCustomer Account rewardTransaction user A is processed Stock & Order are just perfectly synchronizeUser B buy a book on seller BTransaction user B is processed then

Who care the synchronization of vendor A & B ?

Choose your datastore wisely

You can should use many datastores

Datastore choices are driven by usage

Use online database / be ready to test in just a few minutes No need to trash your computer

{P, DB, S} aaSUse ops free solution to learn and start

Common mistakes

Do not use the file system as a datastoreFile system are POSIX compliantPOSIX is ACIDPOSIX is powerful but is a bottleneck File System is the nightmare of ops File System creates coupling (host provider/OS/language)SPOF-free multi tenant File System is a unicorn

Store in database, or in a datastore like S3/riakCS dedicated to file management

Do not use the file system as a datastore

Logs in files I hate it

Use streaming I/O to stream data directly to database

Use streaming I/O to stream data directly to database

Do not use memory as databaseLike : Shared / global variable, cache in the code, intensive session usage

Do not use a variable for more than one request

disposable43

F(x) = x * 2f(2) = 4^ we assume thatFor same input, same output

Its like math function

Example : GET should not change data on serverRespect http

data will be lostCode will fail

Careful use of dark magic

Dont be that guy

Do not use a technology because you