Hello @opqrshun !
When the Service is a Consumption plan scale automatically, including scaling down to zero when there's no traffic, which is referred to as a "cold start".
The incoming requests are handled even in high traffic with queueing from Azure itself
You can always change to a Premium Plan which offers consistently fast performance due to pre-warmed instances that are always ready to respond to requests.
Now , for the Logging , once a request even if it is erroneous , it should be logged , of course you must have Application Insights enabled , and relevant logging on your setup!
If a request never reaches the Azure function because of a network error or similar, then the Azure function itself can't log it,
You can also look the Durable Functions :
Durable Functions is an extension of Azure Functions that lets you write stateful functions in a serverless compute environment. The extension lets you define stateful workflows by writing orchestrator functions and stateful entities by writing entity functions using the Azure Functions programming model. Behind the scenes, the extension manages state, checkpoints, and restarts for you, allowing you to focus on your business logic.
The Durable Task Framework allows for long-running, durable, and reliable stateful operations. It provides capabilities like chaining functions together in a sequence and waiting for human intervention or approval before proceeding.
I hope this helps!
Kindly mark the answer as Accepted and Upvote in case it helped!