Polly Framework VS Microsoft Transient Fault Handling

Question

I want to introduce transient fault handling in our .net application. I saw two nu-get packages are available as of now. One is Polly framework and the other one is Microsoft transient fault handling application block.

We investigated and saw both support asynchronous functions and different retry strategies. Polly framework also supports circuit breaker additionally. Could someone suggest which framework to use with some solid reasons. Also, it would be really helpful if pros and cons of both the frameworks along with support on internet community and scope for future extension and support can be highlighted. Thanks in advance.

Quadratics

I would go with Polly - it's lighter weight and easier to work with - lower friction. disclaimer: I have not worked with the application block solution. – Brioche

Additionally, the MSTFHAB (as I will call it from now on) appears to be designed for use only for Azure hosted application, though it can be made to work on premise too. – Brioche

Thanks for your replies. Yes Microsoft's solutions also works with the in house application that throws transient errors. One important thing which i noticed on MSDN blog is : This is already part of Azure package and should be used from there itself directly and on msdn is is marked as obsolete as well in few articles. – Quadratics

Answer 1

Answering as [disclosure] the lead dev on Polly under the App-vNext umbrella, I'll confine myself to factual answers to your question about support from the internet community and future prospects for the library:

• In December 2015, stewardship of Polly was taken over by http://www.appvnext.com/, a consortium of developers from around the globe led by Carl Franklin of dotnetrocks.
• Between December 2015 and April 2016, the App-vNext team made 10 new releases of the Polly library. New features include full async support (including cancellation and continuation context control), and a new AdvancedCircuitBreaker for high-throughput scenarios.
• The future project Roadmap is public at https://github.com/App-vNext/Polly/wiki/Polly-Roadmap. Envisaged features see Polly grow towards a more fully-fledged fault tolerance library, as Hystrix is for Java.
• EDIT AUTUMN 2016: Polly v5.0 has added a number of new resilience features: Bulkhead isolation; Fallback; Timeout any delegate; PolicyWrap.
• EDIT: Polly is (since end October 2016) a DotNetFoundation-supported project.
• EDIT May 2017: Microsoft patterns-and-practices team officially recommends Polly in place of Topaz in certain scenarios.
• EDIT January 2018: Microsoft plans to make it easy to use Polly as outgoing middleware for HttpClient calls, in the HttpClientFactory planned for .NET Core 2.1.
• EDIT May 2018: ASPNET Core 2.1 released with Polly as outgoing middleware for calls through HttpClient configured with IHttpClientFactory: ms doco; Polly doco.

The Polly team will welcome any community feedback from the SO community!

Pittel

The story is like Newtonsoft Json.Net which is now recommended by MS (de)serializer for JSON. The competition of alternatives is good, but focusing on de facto winner is great. – Kilovoltampere

I've changed my mind and now I look for a simple alternative to Polly. It's just too sophisticated for real use. P.S. It is worth noting Json.Net was fired from .Net and is replaced by System.Text.Json now – Kilovoltampere

So what is the microsoft library for? – Axon

@YonatanNir It is deprecated, not maintained anymore, just forget that library – Quick

@PeterCsala Is there a retry library from MS? – Axon

@YonatanNir Even though polly did not start its career as MS library, now it is a valuable member of the .NET foundation. Please also note that the integration between polly and httpclient is now owned by the asp.net team (microsoft.extensions.http.polly package). – Quick