DevOps Incident Library
Searchable library of real-world failure patterns and fixes. Find the error you are seeing, understand the root cause, and fix it fast.
65 incidents found
Kubernetes Pod CrashLoopBackOff
Pod status shows CrashLoopBackOff
Kubernetes Pod OOMKilled
Pod status shows OOMKilled
Kubernetes ImagePullBackOff
Pod status shows ImagePullBackOff or ErrImagePull
Nginx 502 Bad Gateway
Users see '502 Bad Gateway' error page
Nginx 504 Gateway Timeout
Users see '504 Gateway Timeout' after a long wait
Docker No Space Left on Device
Docker build fails with 'no space left on device'
Terraform State Lock Error
Terraform plan/apply fails with 'Error acquiring the state lock'
AWS Access Denied / Unauthorized
AWS CLI or SDK returns 'Access Denied' or 'UnauthorizedAccess'
SSL/TLS Certificate Expired
Browser shows 'Your connection is not private' or NET::ERR_CERT_DATE_INVALID
DNS Resolution Failure
curl or wget fails with 'Could not resolve host'
PostgreSQL Too Many Connections
Application errors: 'FATAL: too many connections for role'
Redis Memory Limit Exceeded
Redis returns OOM command not allowed when used memory > maxmemory
GitHub Actions Process Completed with Exit Code 1
GitHub Actions workflow fails with 'Process completed with exit code 1'
Jenkins Pipeline Timeout
Jenkins build shows 'Cancelling nested steps due to timeout'
Helm Release Already Exists
helm install fails with 'cannot re-use a name that is still in use'
Docker Container Exiting Immediately
Container starts and immediately exits (status 'Exited')
Terraform Provider Authentication Failure
Terraform init fails with 'Error configuring provider'
Kubernetes Pod Stuck in Pending State
Pod stays in Pending state indefinitely
Linux Permission Denied Errors
Command fails with 'Permission denied'
Kubernetes Service Not Reachable
curl to ClusterIP service returns 'Connection refused' or times out
Docker Build Context or Layer Failure
docker build fails with 'COPY failed: file not found in build context'
Linux Disk Full / No Inodes Left
Commands fail with 'No space left on device'
Kubernetes Pods Evicted
Pods show status 'Evicted'
AWS EC2 Instance Unreachable via SSH
SSH connection times out: 'Connection timed out'
Nginx 413 Request Entity Too Large
File uploads fail with '413 Request Entity Too Large'
Terraform Drift Detected / State Mismatch
terraform plan shows unexpected changes to resources you did not modify
CI/CD Docker Push Access Denied
docker push fails with 'denied: requested access to the resource is denied'
Kubernetes ConfigMap/Secret Changes Not Applied
Updated ConfigMap or Secret but pods still use old values
AWS S3 Access Denied (403 Forbidden)
S3 operations return '403 Forbidden' or 'Access Denied'
CI/CD Git Clone or Checkout Failure
CI pipeline fails at git checkout/clone step
PostgreSQL Deadlock Detected
Application errors: 'ERROR: deadlock detected'
Kubernetes Node NotReady
kubectl get nodes shows one or more nodes in NotReady state
AWS Lambda Function Timeout
Lambda returns 'Task timed out after X seconds'
Docker Container Network Connectivity Issues
Container cannot reach external hosts: 'Could not resolve host'
Nginx Cannot Connect to Unix Socket
Nginx error log: 'connect() to unix:/path/to/socket failed (13: Permission denied)'
Kubernetes HPA Not Scaling Pods
HPA shows <unknown> for current metrics
Kubernetes PVC Stuck in Pending State
PVC status shows Pending indefinitely
Kubernetes Ingress Returns 404 for All Paths
All requests to the ingress return 404 Not Found
Ansible SSH Connection Timeout
Ansible playbook hangs on 'Gathering Facts'
Ansible 'Permission denied' with become/sudo
Task fails with 'Permission denied' when using become: true
Prometheus High Cardinality Causing OOM
Prometheus consuming excessive memory and getting OOMKilled
Grafana Dashboard Showing 'No Data'
Grafana panels display 'No data' despite metrics existing in Prometheus
Envoy Proxy 503 No Healthy Upstream
All requests returning 503 Service Unavailable
HAProxy Max Connection Limit Reached
New connections being refused or queued
Istio Sidecar Not Injected Into Pods
Pods running with only 1/1 containers instead of 2/2
HashiCorp Vault Sealed and Inaccessible
Vault API returns 503 with 'Vault is sealed'
ArgoCD Application Sync Failed — OutOfSync
ArgoCD app status shows OutOfSync with sync failed
ArgoCD Image Updater Not Detecting New Images
New container images pushed to registry but ArgoCD doesn't update
GCP IAM Permission Denied on Service Account
API calls returning 403 PERMISSION_DENIED
Azure NSG Blocking Network Traffic
VM or AKS pods unable to reach external services
AWS RDS Storage Full — Database Unresponsive
Database queries timing out or failing
GKE Node Pool Exhausted — Pods Unschedulable
Pods stuck in Pending state with 'Insufficient cpu' or 'Insufficient memory'
Terraform Apply Timeout on Resource Creation
terraform apply hangs and eventually times out
Docker Compose Port Already in Use
docker compose up fails with 'port is already allocated'
GitHub Actions Runner Disk Full During Build
Build fails with 'No space left on device'
GitLab CI Pipeline Stuck in Pending State
Pipeline jobs show 'pending' indefinitely
Redis Replication Lag Causing Stale Reads
Application reading stale data from Redis replicas
Elasticsearch Cluster Health Red
Cluster health API returns red status
AWS ALB Returning 502 Bad Gateway
ALB returning 502 errors to clients
Pulumi Stack Locked — Concurrent Update Conflict
pulumi up fails with 'the stack is currently locked'
Systemd Service Failed to Start
Service shows 'failed' status in systemctl
Linux TCP Connection Refused
curl/wget returns 'Connection refused'
AWS ECS Task Stopped Unexpectedly
ECS tasks in STOPPED state with 'Essential container exited'
MongoDB Connection Pool Exhausted
Application errors: 'MongoTimeoutError: connection timed out'
Cloudflare 522 Connection Timed Out to Origin
Users seeing Cloudflare 522 error page