LogLens AI / Errors

Error & log reference

Clear, practical fixes for the errors you actually see in logs — what each means, how to diagnose it, and how to fix it. LogLens AI finds and explains these automatically.

connection refused
"Connection refused" means nothing is listening on the target host and port, or a firewall rejected the connec…OOMKilled (exit 137)
Exit code 137 / OOMKilled means a container exceeded its memory limit and the kernel OOM killer stopped it. Ca…502 Bad Gateway
A 502 Bad Gateway means nginx reached your upstream app but got an invalid or no response — usually the app is…504 Gateway Timeout
A 504 Gateway Timeout means the proxy reached your upstream app but it did not respond in time. Causes, diagno…500 Internal Server Error
A 500 Internal Server Error is a generic server-side failure — an unhandled exception in your app. Here is how…CrashLoopBackOff
CrashLoopBackOff means a Kubernetes container keeps starting then crashing, so kubelet backs off restarting it…ImagePullBackOff
ImagePullBackOff means Kubernetes cannot pull your container image — wrong name/tag, missing registry credenti…java.lang.OutOfMemoryError
java.lang.OutOfMemoryError means the JVM could not allocate memory — usually a heap too small or a memory leak…Too many open files
"Too many open files" (EMFILE) means a process hit its file-descriptor limit — too low a ulimit, or a leak of …Address already in use (EADDRINUSE)
EADDRINUSE / "address already in use" means the port your app wants is already bound by another process. How t…