Investigate retrys when pulling from harbor proxy repositories

[Atomsoldat]

Images take longer to pull than usual, because layers need to be retried

The retries happen not only on the first pull. All subsequent pulls have the same issue. e.g.:

docker rmi harbor.nekropolis.irminsul/dockerhub-proxy/pengbai/docker-supermario
docker pull harbor.nekropolis.irminsul/dockerhub-proxy/pengbai/docker-supermario              
  Using default tag: latest                               
  latest: Pulling from                                    
  dockerhub-proxy/pengbai/docker-supermario               
  092586df9206: Retrying in 3 seconds                     
  ef599477fae0: Retrying in 3 seconds

harbor-core logs:

2026-02-28T14:45:39Z [WARNING] [/server/middleware/repoproxy/p
roxy.go:227]: Artifact: dockerhub-proxy/pengbai/docker-superma
rio:, digest:sha256:8d909e68fbc38de1dc6bef982e0ca8c364f3c80215
25c9487cec4374a53f15f5 is not found in proxy cache, fetch it f
rom remote repo                                               
2026-02-28T14:45:43Z [ERROR] [/lib/http/error.go:58]: {"errors
":[{"code":"UNKNOWN","message":"unknown: write tcp 10.0.6.77:8
080-\u003e10.0.2.102:43923: write: broken pipe"}]}            
2026-02-28T14:45:43Z [ERROR] [/lib/http/error.go:58]: {"errors
":[{"code":"UNKNOWN","message":"unknown: write tcp 10.0.6.77:8
080-\u003e10.0.2.102:38837: write: broken pipe"}]}            
2026-02-28T14:45:43Z [ERROR] [/lib/http/error.go:58]: {"errors
":[{"code":"UNKNOWN","message":"unknown: write tcp 10.0.6.77:8
080-\u003e10.0.2.102:43535: write: broken pipe"}]}            
2026-02-28T14:45:50Z [ERROR] [/lib/http/error.go:58]: {"errors
":[{"code":"UNKNOWN","message":"unknown: write tcp 10.0.6.77:8
080-\u003e10.0.3.121:38917: write: broken pipe"}]}