How to Fix DNS Resolution Error in Clojure

Dealing with a DNS Resolution Error in your Clojure project? You're in the right place. Let's solve this step by step.

What Causes This Error

DNS resolution errors in Clojure occur when the runtime can't resolve a hostname to an IP address. This may be caused by misconfigured DNS servers, IPv6/IPv4 issues, network connectivity problems, or transient DNS cache failures.

The Fix

The key is to add socket/connection timeouts and retry logic to clj-http requests:

(require '[clj-http.client :as client])

(defn fetch-with-retry [url]
  (client/get url
    {:socket-timeout 10000
     :connection-timeout 5000
     :retry-handler (fn [ex try-count ctx]
                      (< try-count 3))}))

Common Pitfall

If this error appears intermittently, it likely points to a race condition or resource exhaustion issue rather than a simple misconfiguration. Check your connection pool settings and timeouts. Adding a comment in your configuration explaining why this setting exists will save your future self — and teammates — hours of confusion.

Verify the Fix

After applying the fix, restart your Clojure application and verify the error no longer appears in the console or logs. Test both the happy path and edge cases to be thorough. If the error persists, double-check that your changes were saved and the application fully restarted.

Prevention

To prevent this from recurring unnoticed, set up [Bugsly](https://bugsly.dev) for your Clojure project — it monitors errors and gives you actionable alerts.