I'm working on a new game project at the moment that will consist of a React Native front-end and a Lambda-based back-end. The app requires some real time features such as active user records, geofencing, etc.
I was looking at Firebase's Realtime Database that looks like a really elegant solution for real-time data sync but I don't think AWS has anything quite like it.
The 3 options I could think of for "serverless" realtime using only AWS services are:
Option 1: AWS IoT Messaging over WebSockets
This one is quite obvious, a managed WebSockets connection through the IoT SDK. I was thinking of triggering Lambdas in response to inbound and outbound events and just use WebSockets as the realtime layer, building custom handling logic on the app client as you typically would.
The downside to this, at least compared to Firebase, is that I will have to handle the data in the events myself which will add another layer of management on top of WebSockets and will have to be standardized with the API data layer in the application's stores.
Pros:
- Scalable bi-directional realtime connection
Cons:
- Only works when the app is open
- Message structure needs to be implemented
- Multiple transport layers to be managed
Option 2: Push-triggered re-fetch
Another option is to use push notifications as real-time triggers but use a regular HTTP request to API Gateway to actually get the updated payload.
I like this approach because it sticks to only one transport layer and a single source of truth for application state. It will also trigger updates when the app is not open since these are Push Notifications.
The downside is that this is a lot of custom work with potentially difficult mappings between push notifications to the data that needs to be fetched.
Pros:
- Push notifications work even when app is closed
- Single source of truth, transport layer
Cons:
- Most custom solution
- Will involve many more HTTP requests overall
Option 3: Cognito Sync
This is newer to me and I'm not sure if it can actually be interfaced with from the server.
Cognito Sync offers user state sync. across devices complete with offline support and is part of the Cognito SDK which I'll be using anyway. It sounds like just what I'm looking for but couldn't find any conclusive evidence as to wether it is possible to modify, or "trigger", updates from AWS and not just from one of the devices.
Pros:
- Provides an abstracted real-time data model
- Connected to Cognito user records OOTB
Cons:
- Not sure if can be modified or updated from Lambdas
I'm wondering if anyone has experience doing real-time on AWS as part of a Lambda-based architecture and if you have an opinion on what is the best way to proceed?
I asked a similar question to the AWS Support, and this was their response.
My question to them:
What's the group of AWS services (if it's possible) to give that same
in-browser real-time DBaaS feel like Firebase?
AWS Cognito seems to be great for user-accounts. Is there anything
similar for the WebSockets / real-time DB part?
Their response:
To your question, Firebase is closest to the AWS service AWS
MobileHub. You can check out more details below about mobilehub from
below link.
https://aws.amazon.com/mobile/details/
https://aws.amazon.com/mobile/getting-started/
"AWS Cognito seems to be great for user-accounts. Is there anything
similar for the WebSockets / real-time DB part?"
Amazon Dynamodb is a fast and flexible NoSQL database service for all
applications that need consistent, single-digit millisecond latency at
any scale. It is a fully managed cloud database and supports both
document and key-value store models. Its flexible data model, reliable
performance, and automatic scaling of throughput capacity, makes it a
great fit for mobile, web, gaming, ad tech, IoT, and many other
applications.
Amazon Dynamodb can be further optimized with Amazon DynamoDB
Accelerator (DAX) which is a fully managed, highly available,
in-memory cache that can reduce Amazon DynamoDB response times from
milliseconds to microseconds, even at millions of requests per second.
For more information, please see below documentation.
https://aws.amazon.com/dynamodb/getting-started/
https://aws.amazon.com/dynamodb/dax/
Should you have any further questions, please do not hesitate to let
me know.
Thanks.
Best regards,
Tayo O. Amazon Web Services
Check out the AWS Support Knowledge Center, a knowledge base of
articles and videos that answer customer questions about AWS services:
https://aws.amazon.com/premiumsupport/knowledge-center/?icmpid=support_email_category
Also while researching this answer I also found this, looks interesting:
https://aws.amazon.com/blogs/database/how-to-build-a-chat-application-with-amazon-elasticache-for-redis/
The comments to that article is interesting as well.
Jacob Wakeem:
What advantage this
approach have over using aws iot? It seems that iot has all these
functionality without writing a single line of code and with
server-less architecture.
Sam Dengler:
The managed PubSub feature in the AWS IoT
service is also a good approach to message-based applications, like
the one demonstrated in the article. With Elasticache (Redis),
customers who use Pub/Sub are typically also using Redis as a data
store for other use cases such as caching, leaderboards, etc. With
that said, you could also use ElastiCache (Redis) with the AWS IoT
service by triggering an AWS Lambda function via the AWS IoT rules
engine. Depending on how the message-based application is architected
and how the data is leveraged, one solution may be a better fit than
the other.
Check out AWS AppSync for some of these realtime and offline features using different data sources, including databases search and compute.
Sounds like AWS Serverless is most suited alternative.
Also wondering: AWS vs Firebase - Is It Even a Fair Fight?
