AppSync subscription stopped working after creating the 6th DynamoDB item

Question

For some unknown reason, when there are 6+ items in a DynamoDB table, the createItem() subscription doesn't work, even when I was trying it in AWS AppSync console. No response at all after invoking createItem() through code, but the item gets created in DynamoDB though.  
  
Is there a limit to the number of items in DynamoDB to subscriptions?  
  
Edited by: PaulLTC on Jul 28, 2021 10:24 AM  
  
Edited by: PaulLTC on Jul 28, 2021 10:25 AM

Answer

The solution to this is to create my own Custom query and subscription instead of the generated ones, and only include the ones I want in the payload.  
The generated query and subscription have ~2.9k lines of code, and with hours of testing in AppSync console, I discovered that it probably exceeded the payload size (240KB over WebSockets and 120KB MQTT over WebSockets).  
https://docs.aws.amazon.com/general/latest/gr/appsync.html  
  
It is not too friendly that not even an error is thrown when the accumulated payload size is exceeded.

AppSync subscription stopped working after creating the 6th DynamoDB item

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