HighRes Image Loading Failure in iOS 18 with KFImage in List/ForEach

goojoob commented 1 week ago

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Issue Description

What

On iOS 18 (Xcode 16.0), KFImages frequently fail to show up when used inside List/ForEach. I have high quality images and use the DownsamplingImageProcessor, but only some of them load successfully, while the rest remain stuck in a loading state, and I see the following log: nw_connection_add_timestamp_locked_on_nw_queue [C1] Hit maximum timestamp count, will start dropping events

Interestingly, if I switch from WiFi to 5G, the images start loading again, but the loading stalls once more after a few additional images, showing again the same message log.

Reproduce

@State var allImages: [String] = //the content of this array is in https://oldschool.cat/allImages.swift please copy paste here the content

    var body: some View {
        NavigationStack {
            List {
                ForEach(allImages, id: \.self) { release in
                    if let image = URL(string: release) {
                        KFImage(image)
                            .placeholder {
                                ProgressView()
                            }
                            .retry(maxCount: 3, interval: .seconds(3))
                            .setProcessor(DownsamplingImageProcessor(size: CGSize(width: 100, height: 100)))
                    }
                }
            }
        }
    }

Other Comment

You can check the behaviour in this video: https://youtu.be/043Uy0i9LcE

onevcat commented 1 week ago

Upon investigating the URLs provided, I found that the server is returning HTTP status code 429 (Too Many Requests), indicating that the requests are being rate-limited.

Error: responseError(reason: Kingfisher.KingfisherError.ResponseErrorReason.invalidHTTPStatusCode(response: <NSHTTPURLResponse: 0x6000003116a0> { URL: https://i.discogs.com/....NC5qcGVn.jpeg } { 
    Status Code: 429, Headers 
{
    "Alt-Svc" =     (
        "h3=\":443\"; ma=86400"
....
}

This status code 429 is specifically designed to indicate when a user has exceeded the allowed number of requests within a given time period. The server implements these rate limits to prevent excessive concurrent requests (such as multiple simultaneous image loads). This explains why switching networks temporarily resolves the issue - the new network connection presents a different client IP address to the server, effectively resetting the rate limit counter.

Since this is a server-side rate limiting mechanism rather than a Kingfisher-related issue, I recommend closing this ticket. Please don't hesitate to reach out if you have any additional questions or concerns.

goojoob commented 1 week ago

Thanks for the answer @onevcat , that make sense now. I've checked the server rate limits and it says: Your application should identify itself to our servers via a unique user agent string in order to achieve the maximum number of requests per minute. I guess i'll configure the user-agent in ImageDownloader to get the maximum quota.

onevcat / Kingfisher