HTTP 502 from Silent Connection Failures
criticalConnection ManagementUpdated Feb 23, 2026
Linkerd proxies return HTTP 502 when backend connections are refused or closed without explanation. These errors often become visible only after mesh injection, exposing previously undetected connection issues.
Sources
How to detect:
Monitor for increased HTTP 502 responses after Linkerd injection, especially when application logs show no errors. Check for connection refusal patterns and idle timeout mismatches between proxy and application.
Recommended action:
Verify server idle timeouts are sufficiently long (check server config for values like Go's http.Server idle timeout). Investigate half-closed connection accumulation using Linkerd's detection script. Consider increasing close-wait timeout via --close-wait-timeout flag during injection, or adjust connection pooling settings.