You can become a serverless blackbelt. Enrol to my 4-week online workshop Production-Ready Serverless and gain hands-on experience building something from scratch using serverless technologies. At the end of the workshop, you should have a broader view of the challenges you will face as your serverless architecture matures and expands. You should also have a firm grasp on when serverless is a good fit for your system as well as common pitfalls you need to avoid. Sign up now and get 15% discount with the code yanprs15!
In F#, you have the choice of using a struct or a record as a lightweight container for data. The similarities between the two are striking – both are immutable by default, neither can be inherited, and they both offer structural equality semantics by default too!
However, there’s a key difference between them, their performance characteristics.
When you’re dealing with tons of small objects, structs offer significant performance benefits because as value types they are stack allocated which is much faster, and don’t need to be garbage collected.
Records on the other hand, are reference types, and are therefore heap allocated (plus pointers on the stack), which is slower, and require the extra step of garbage collection when they’re no longer referenced.
As a simple test, given these two identical types, one as a struct and one as a record:
The snippet below constructs two arrays each with 10 million items, one with struct instances and the other with record instances:
Over three runs, the structs array took an average of 0.146 seconds to construct whilst the records array took an average of 2.919 seconds!
Although this test shows that creating large numbers of records takes significantly longer than structs, in practice however, would you really care if generating 10 millions objects takes 3 seconds instead of 0.1? Is that likely to be the source of your performance issues?
All and all, the performance gains you get by using structs over records is negligible, in most cases you won’t be generating large number of these objects frequently enough for you to notice the difference. Also, we haven’t even covered the cost of copying them when passing them as parameters (Value types are passed by value as opposed to reference), which if you’re not careful can have a detrimental effect on the overall performance of your application.
Also, records have two very useful features for working with F# which structs don’t:
- type inference can infer a record’s type, no need for type annotation
- records can be used as part of standard pattern matching, no need for when guards
both are big pluses in my book and worth considering when you’re choosing between records and structs.
Hi, I’m Yan. I’m an AWS Serverless Hero and I help companies go faster for less by adopting serverless technologies successfully.
Are you struggling with serverless or need guidance on best practices? Do you want someone to review your architecture and help you avoid costly mistakes down the line? Whatever the case, I’m here to help.
Skill up your serverless game with this hands-on workshop.
My 4-week Production-Ready Serverless online workshop is back!
This course takes you through building a production-ready serverless web application from testing, deployment, security, all the way through to observability. The motivation for this course is to give you hands-on experience building something with serverless technologies while giving you a broader view of the challenges you will face as the architecture matures and expands.
We will start at the basics and give you a firm introduction to Lambda and all the relevant concepts and service features (including the latest announcements in 2020). And then gradually ramping up and cover a wide array of topics such as API security, testing strategies, CI/CD, secret management, and operational best practices for monitoring and troubleshooting.
If you enrol now you can also get 15% OFF with the promo code “yanprs15”.
Check out my new podcast Real-World Serverless where I talk with engineers who are building amazing things with serverless technologies and discuss the real-world use cases and challenges they face. If you’re interested in what people are actually doing with serverless and what it’s really like to be working with serverless day-to-day, then this is the podcast for you.
Check out my new course, Learn you some Lambda best practice for great good! In this course, you will learn best practices for working with AWS Lambda in terms of performance, cost, security, scalability, resilience and observability. We will also cover latest features from re:Invent 2019 such as Provisioned Concurrency and Lambda Destinations. Enrol now and start learning!
Check out my video course, Complete Guide to AWS Step Functions. In this course, we’ll cover everything you need to know to use AWS Step Functions service effectively. There is something for everyone from beginners to more advanced users looking for design patterns and best practices. Enrol now and start learning!
Here is a complete list of all my posts on serverless and AWS Lambda. In the meantime, here are a few of my most popular blog posts.
- All you need to know about caching for serverless applications
- Lambda optimization tip – enable HTTP keep-alive
- You are wrong about serverless and vendor lock-in
- You are thinking about serverless costs all wrong
- Just how expensive is the full AWS SDK?
- Check-list for going live with API Gateway and Lambda
- How to choose the right API Gateway auth method
- CloudFormation protip: use !Sub instead of !Join
- AWS Lambda – should you have few monolithic functions or many single-purposed functions?
- Guys, we’re doing pagination wrong
- Top 10 Serverless framework best practices
- How to break the “senior engineer” career ceiling
- My advice to junior developers