Aws-lambda-dotnet: Guidance for HttpClient life-cycle in Lambdas

Created on 4 Jun 2018 · 4Comments · Source: aws/aws-lambda-dotnet

Microsoft recommends, for most use-cases, that you create a singleton of HttpClient, configure it and share it for the life-cycle of the app, or Http request in some cases.

How do Lambda's work in regards to this? Each time my Lambda fires (regardless if cold/warm) is it the same process running each time or a new dotnet process? If it's a new dotnet process each time then I can safely just instantiate and dispose of the HttpClient because it's only used once through-out the life-cycle of the Lambda. If the same process is re-used (with the handler invoked multiple times) then I need to handle the life-cycle of my HttpClient differently.

Any guidance on how we should treat the usage of HttpClient in Lambda's would be appreciated.

guidance

Source

scionwest

Most helpful comment

Here is my talk from NDC Minnesota last month. If you skip ahead to about 2:40 into I go through the lifecycle of a Lambda environment which will hopefully clear things up for you.

https://vimeo.com/271358846

normj on 4 Jun 2018

👍3

All 4 comments

Here is my talk from NDC Minnesota last month. If you skip ahead to about 2:40 into I go through the lifecycle of a Lambda environment which will hopefully clear things up for you.

https://vimeo.com/271358846

normj on 4 Jun 2018

👍3

Answered my question, thanks!

scionwest on 4 Jun 2018

This was so helpful! Although this is 2 years too late, Thanks! @normj

judedaryl on 16 Apr 2020

Thanks @normj

For anyone who comes across this searching for answers - create a singleton HttpClient, it should survive a few invocations of events until such time that you had a long period of inactivity and Lambda destroys the environment running your code.