Retry Simulator

Retry Simulator was designed to simulate, observe & collect retry patterns handling capability results with services using .NET Polly framework. Run the simulator to identify the right retry pattern handling.

Benefits

1. Fires concurrent requests to server to simulate real-time retries. (Note - use it with extreme cautious)
2. Local server provided without needing to create a server to simulate retries and understand how it works.
3. Simulate retries with public server directly using simple JSON configuration file.
4. Provides tokenization(e.g. correlation-id) which able to correlate requests from client & server.
5. Writes results to project /Result directory in CSV format to visualize the data.

Dependancies

1. Visual Studio 2019/Visual Studio Code
2. Download .NET 5 Build SDK
3. Ensure Visual Studio 2019 IDE have been configured with Nuget package source : https://api.nuget.org/v3/index.json

Guide to setup & run project locally

Clone RetrySimulator GitHub project to your preferred environment.

Running client simulator

1. Open preferred Windows Terminal & navigate to project(<project path>/Client)
2. Run dotnet run command
3. Choose based on the retry option below:
   • Constant Backoff (e.g. 1s, 1s, 1s)
   • Linear Backoff (e.g. 1s, 2s, 3s)
   • Exponential Backoff (e.g. 1s, 2s, 4s, 8s)
   • Exponential Jitter Backoff (e.g. 1.123s, 2.456s, 4.768s, 8.125s)
   • RetryAfter Backoff (e.g. 5s, 5s, 5s)
   • Aws Decorrelated Jitter Backoff (e.g. 1.123s, 2.456s, 2.768s, 4.125s)
   • Decorrelated Jitter Backoff V2 (e.g. 1.555s, 2.223s, 2.123s, 3.233s)
4. Configure appSettings.json:

{
 "retry": {
   "minDelayIsMs": 1000,
   "maxDelayIsMs": 5000,
   "maxRetry": 50,
   "jitterStart": 1,
   "jitterEnd": 1000

 },
 "request": {
   "method": "Post|Get|Update|Delete",
   "requestUri": "https://localhost:5001/api/service?id={{ id }}",
   "headers": {
     "Authorization": "Bearer <token>",
     "Correlation-ID": "{{ id }}",
   },
   "contentHeaders": {
     "Content-Type": "application/json"
   },
   "body": "{\"correlation-id\":\"{{ id }}\"}"
 }
}

Running local server simulator

1. Open preferred Windows Terminal & navigate to project (<project path>/Server)
2. Run dotnet run command

Compatibility

Windows

What's next?

1. To research on how to throttle/drop/lag incoming & outgoing traffic for Windows/Linux.
2. Package as an .EXE format