[GH-ISSUE #3198] Deduplicate concurrent queries in `Resolver` #1151

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opened 2026-03-16 01:44:38 +03:00 by kerem · 1 comment

kerem commented

2026-03-16 01:44:38 +03:00

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Originally created by @divergentdave on GitHub (Aug 12, 2025).
Original GitHub issue: https://github.com/hickory-dns/hickory-dns/issues/3198

We got a report that making a very large number of concurrent queries when using reqwest with Hickory DNS enabled may result in FD exhaustion during DNS resolution. Currently, we deduplicate concurrent requests in RecursorPool and MemoizeClientHandle (see also #3119). However reqwest uses TokioResolver, which just has a cache in CachingClient, but does not deduplicate identical concurrent queries. We should apply a similar solution to this API.

Originally created by @divergentdave on GitHub (Aug 12, 2025). Original GitHub issue: https://github.com/hickory-dns/hickory-dns/issues/3198 We got a report that making a very large number of concurrent queries when using `reqwest` with Hickory DNS enabled may result in FD exhaustion during DNS resolution. Currently, we deduplicate concurrent requests in `RecursorPool` and `MemoizeClientHandle` (see also #3119). However `reqwest` uses `TokioResolver`, which just has a cache in `CachingClient`, but does not deduplicate identical concurrent queries. We should apply a similar solution to this API.