https://nalar.dev/tags/singleflight/ Recent content in Singleflight on Nalar Hugo en-us Mon, 07 Sep 2026 00:00:00 +0700 https://nalar.dev/suppress-duplicate-concurrent-work-in-go-with-singleflight/ Mon, 07 Sep 2026 00:00:00 +0700 https://nalar.dev/suppress-duplicate-concurrent-work-in-go-with-singleflight/ <p>A service can become overloaded even when each individual request is reasonable. Imagine a popular product whose cached record expires. Fifty requests arrive almost together, all observe the same cache miss, and all start the same database query.</p> <p>The problem is not ordinary parallelism. Those requests are doing <strong>duplicate work for the same result at the same time</strong>.</p> <p><code>golang.org/x/sync/singleflight</code> provides a small mechanism for suppressing that duplication inside one Go process. For a given key, one caller performs the work while concurrent callers for the same key wait and receive the same result. Calls using different keys can still perform their own work.</p>