AWS re:Invent 2018 Day 1

AWS Certification Lounge

I started my day by swinging to the Certification Lounge to get a coffee.

This year there were a lot for rewards for certified people:

AWS Certified SWAG

  • AWS Certified T-Shirt
  • AWS Certified hat
  • AWS Certified bottle
  • AWS Certified pins (depending on your level of certifications)

ARC215: Which database is right for your serverless application


My first session of the day was a chalk talk:

  • small group (60 people)
  • quick presentation (~15 minutes)
  • Questions/Discussions (~45 minutes)

The speakers started by stating the specific serverless characteristics that differ from traditional applications:

  • Horizontal scaling
  • Ephemeral execution
  • Event-driven

They then went on to present the different options on AWS.

NoSQL to the rescue

Of course, DynamoDB is the default choice to enjoy all the serverless qualities.

But what if you need search capabilities? Then you have to go back to ElasticSearch.

DynamoDB is also not suited for large objects, so in this case, you should use S3.

Don’t care about data persistence? Use ElastiCache for its low latency.

Still think you need a relational database?

RDS is still there but beware of the number of connections you serverless applications might create. Moreover you will have to provision and manage your own VPC.

Aurora Serverless takes a bit of the hassle out of the way with it’s managed scaling. And with the new Data API in beta, you don’t even need your lambda in a VPC anymore.

Interesting questions from the attendees

How to handle up to 0.5 Millions increment operations per seconds?
DynamoDB can handle that kind of traffic but the cost is quite prohibitive: 170k$/day! So you would have to handle batch writes directly from your application.

What are the differences between VPC lambdas and non-VPC?
Lambdas running inside a VPC need to allocate an ENI at the start which is much longer (a few seconds). But after the cold start, it might be faster to access resources inside your VPC.

How to handle connections to Aurora Serverless?
No application changes are needed because there is a proxy fleet handling connections.

Does Aurora Serverless support multi-master or read replicas?
No, Aurora Serverless uses a proxy fleet that will connect to the right instance for you.

How to use Aurora Serverless Data API?
Mostly like DynamoDB access, you will need to use IAM credentials and the API. However, it also requires access to the database credentials inside an AWS Secrets Manager.

DVC306: Serverless, it all started in Vegas


This time it was a breakout session, a classic 60 minutes long lecture.

TrustPilot gave us feedback on how they moved to and use Serverless. First of all, they were already Cloud Native, used event-drive micro-services and REST API.

Back at re:invent 2016, Serverless started to make sense but they had to wait till February 2016 for VPC support.

They were already using Publish/Subscribe messaging pattern with traditional auto scaling on queues and moved it to serverless with instant scaling instead.

They applied a Serverless first approach to all their projects. If they really could not do serverless, they would at least use containers.

They found it great for hackathon and making prototypes that can scale.

They established a “GTFO EC2” policy, with weekly meetings for each team, to work on removing all kinds of EC2 instances.

When asked if Lambda is really cheaper, they recognized it’s hard to compare compute and operational cost at the same time. But the key takeaways are:

  • Gutfeel is - for TrustPilot - they are 10x cheaper
  • Less ops heavy
  • Faster development for services at scale

The only downside is a decrease of observability and traceability in the absence of good tooling.

But anyway, they would do it all again in a heartbeat.

Monday Night Live

Monday Night Live was hosted again by Peter Desantis, they announced a few launches, previews and pre-announcements:



  • P3dn Instance type


  • Elastic Fabric Adapter
  • AWS IoT Events
  • AWS IoT SiteWise
  • AWS IoT Things Graph

I am a bit disappointed by the announcements at Monday Night Live but it’s still early in the week.

Stay Tuned!