Request Retrying when offline #3948

gouravkmar · 2025-03-24T22:47:20Z

Issue Link 🔗
No specific issue was raised for this feature; this PR introduces a network-aware request retrier that automatically reattempts failed requests when the network becomes available.

Goals ⚽
Implement an automatic retry mechanism that waits for network availability.

Improve request handling by reducing manual retry efforts for network-related failures.

Implementation Details 🚧
Introduced NetworkAwareRetrier, a custom RequestRetrier that integrates with Alamofire sessions.

Utilized NWPathMonitor to detect network status changes and store pending retries.

Ensured thread safety using a concurrent queue with barrier flags for state management.

Maintained a queue of pending retry completions, executing them once the network is restored.

Usage 🚀
1️⃣ Adding NetworkAwareRetrier to an Alamofire Session
To enable automatic request retries for all requests within a session:

let retrier = NetworkAwareRetrier()
let session = Session(interceptor: retrier)

session.request("https://example.com/api/").response { response in
    print("Request completed")
}

2️⃣ Using NetworkAwareRetrier for a Specific Request
If you want to apply the retrier only to a specific request without affecting the entire session, you can use

request(_:method:interceptor:):

let retrier = NetworkAwareRetrier()
let session = Session()

session.request("https://example.com/api/", interceptor: retrier).response { response in
    print("Request completed")
}

This ensures that only the specific request will retry when network connectivity is restored, while other requests in the session remain unaffected.

Testing Details 🔍
Unit Tests: Verified that failed requests are queued and retried once the network becomes available.

Manual Testing: Simulated network loss and recovery scenarios to confirm expected retry behavior.

Concurrency Testing: Ensured thread-safe access to shared properties.

jshier · 2025-03-25T23:10:14Z

Thanks for the PR, we've wanted something like this! However, there's no need for custom caching here, Alamofire's retry feature already handles that. All you need to do here is create a custom RequestRetrier-conforming type and handle the retry logic in there, Alamofire can asynchronously wait to know whether to retry.

Additionally, given the imminent deprecation of NetworkReachabilityManager, you should rebuild on top of NWPathMonitor. That will ensure it works well into the future.

With those changes I can do a more detailed review and we can get this merged.

gouravkmar · 2025-03-26T16:56:34Z

Thanks for the PR, we've wanted something like this! However, there's no need for custom caching here, Alamofire's retry feature already handles that. All you need to do here is create a custom RequestRetrier-conforming type and handle the retry logic in there, Alamofire can asynchronously wait to know whether to retry.

Additionally, given the imminent deprecation of NetworkReachabilityManager, you should rebuild on top of NWPathMonitor. That will ensure it works well into the future.

With those changes I can do a more detailed review and we can get this merged.

I've added the support of multiple failed requests in case of session wide retrier and removed the custom caching flow, please do check @jshier

gouravkmar · 2025-04-20T09:53:59Z

@marcprux can you please help merge this in case this is fine?

monicadiaz68071978

Approved

Request caching when offline

62f9c21

Removed caching and adopeted the new NWPathMonitor

6e500cf

gouravkmar changed the title ~~Request caching when offline~~ Request Retrying when offline Apr 1, 2025

monicadiaz68071978 reviewed Jun 7, 2025

View reviewed changes

Provide feedback

Saved searches

Use saved searches to filter your results more quickly

Uh oh!

Uh oh!

Request Retrying when offline #3948

Request Retrying when offline #3948

Uh oh!

Uh oh!

Uh oh!

Uh oh!

Uh oh!

Uh oh!

Uh oh!

Uh oh!

Request Retrying when offline #3948

Are you sure you want to change the base?

Request Retrying when offline #3948

Uh oh!

Conversation

Uh oh!

Uh oh!

Uh oh!

Uh oh!

Uh oh!

Uh oh!

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Uh oh!