[GH-ISSUE #3386] Does hickory really cancel requests for dropped futures? #1177

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opened 2026-03-16 01:48:59 +03:00 by kerem · 2 comments

kerem commented

2026-03-16 01:48:59 +03:00

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Originally created by @pronebird on GitHub (Dec 9, 2025).
Original GitHub issue: https://github.com/hickory-dns/hickory-dns/issues/3386

Hi,

I have seen weird behavior with hickory where it seems that dropping future resolving DNS address doesn't cancel the request. I'll investigate a bit more to confirm my assumption. However I wonder if that's somehow a known issue?

When doing many requests and dropping future before it completes, I start seeing the following messages logged:

hickory_resolver::name_server::name_server: name_server connection failure: resource too busy config=NameServerConfig { socket_addr: 1.0.0.1:853, protocol: Tls, tls_dns_name: Some("cloudflare-dns.com"), http_endpoint: None, trust_negative_responses: true, bind_addr: None }

At some point it becomes impossible to resolve anything.

let resolver: TokioResolver = .. // shared tokio resolver

tokio::time::timeout(Duration::from_secs(6), resolver.lookup_ip("github.com")).await

Originally created by @pronebird on GitHub (Dec 9, 2025). Original GitHub issue: https://github.com/hickory-dns/hickory-dns/issues/3386 Hi, I have seen weird behavior with hickory where it seems that dropping future resolving DNS address doesn't cancel the request. I'll investigate a bit more to confirm my assumption. However I wonder if that's somehow a known issue? When doing many requests and dropping future before it completes, I start seeing the following messages logged: > hickory_resolver::name_server::name_server: name_server connection failure: resource too busy config=NameServerConfig { socket_addr: 1.0.0.1:853, protocol: Tls, tls_dns_name: Some("cloudflare-dns.com"), http_endpoint: None, trust_negative_responses: true, bind_addr: None } At some point it becomes impossible to resolve anything. ```rs let resolver: TokioResolver = .. // shared tokio resolver tokio::time::timeout(Duration::from_secs(6), resolver.lookup_ip("github.com")).await ```

kerem closed this issue

2026-03-16 01:49:04 +03:00

kerem commented

2026-03-16 01:49:10 +03:00

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@marcus0x62 commented on GitHub (Dec 9, 2025):

What version of Hickory are you using, and do you have a minimal reproducer for this? How many futures are you dropping when you see this behavior?

@marcus0x62 commented on GitHub (Dec 9, 2025): What version of Hickory are you using, and do you have a minimal reproducer for this? How many futures are you dropping when you see this behavior?

kerem commented

2026-03-16 01:49:15 +03:00

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@pronebird commented on GitHub (Dec 10, 2025):

I ran tests and it seems that hickory works properly. I must be seeing something else.

@pronebird commented on GitHub (Dec 10, 2025): I ran tests and it seems that hickory works properly. I must be seeing something else.