Polly Presentation and Links

I had the honor of going to NDC Minneapolis in 2019 . One of the many presentations I attended was about Polly , given by Carl Franklin (the pictures below are from his presentation slides) I recently gave a presentation of my own at an Omnitech Lunch and Learn. We had a lot of good questions and conversations, so there isn’t a lot of content. If you want to learn more about it, just watch Carl’s presentation . Here is the material I used for the presentation.

App-vNext (Carl Franklin’s company) took Polly over a few years ago. It’s now in the .Net Foundation.

Why would you use Polly?

• You are making network calls
  • Network calls aren’t reliable as you think

How do you use Polly?

We walked through the samples on their GitHub page.

Retrying in Azure

Most Azure services and client SDKs include a retry mechanism . Check out these before deciding if you need to use Polly.

https://docs.microsoft.com/en-us/azure/architecture/best-practices/transient-faults

Jeremy at Omnitech had this to say after our lunch and learn,

"I think that understanding the value Polly brings (and retry strategies in general) is really important for us as consultants. We may not need to use them on every project or client, but when you need to have smart retries there's not a great substitute.

Sometimes, half the battle is knowing that a tool or strategy exists - I would encourage everyone to make sure they understand, at a general level, when automated retries are useful, the problems they solve, when they are dangerous or the wrong solution, and know of a library or two that makes them easier to work with."

Resources:

• http://www.thepollyproject.org/
• Bulletproof Transient Error Handling with Polly - Carl Franklin at NDC 2019
• http://www.appvnext.com/blog/2015/11/19/polly-is-repetitive-and-i-love-it
  • http://www.thepollyproject.org/2019/06/27/simmy-the-monkey-for-making-chaos/
• https://github.com/App-vNext/Polly-Samples
• https://netflix.github.io/pollyjs/
• https://stackoverflow.com/questions/42952057/polly-policy-to-log-exception-and-rethrow/53119097#53119097