1
, DevOps Shack
AWS DevOps Troubleshooting Guide
Table of Contents
1-10: EC2 & Load Balancer Issues
1. EC2 Instance Not Starting
2. EC2 Instance Stuck in “Initializing” State
3. EC2 Instance High CPU Utilization
4. EC2 Instance Unable to Reach the Internet
5. EC2 Instance Connection Timeout (SSH Issues)
6. Elastic Load Balancer (ELB) Not Routing Traffic
7. Target Group in ELB Showing Unhealthy Instances
8. SSL Certificate Not Working on ELB
9. EC2 Auto Scaling Not Launching New Instances
10.EC2 Spot Instance Interrupted Unexpectedly
11-20: S3, IAM, and Permissions Issues
11.S3 Bucket Access Denied (403 Error)
12.S3 Public Access Block Preventing Access
13.S3 Lifecycle Policy Not Deleting Objects
14.S3 Cross-Region Replication Not Working
15.S3 File Upload Extremely Slow
16.IAM Policy Not Granting Expected Access
17.IAM Role Not Attaching to EC2 Instance
, 18.AWS STS Token Expired Error
19.MFA Authentication Failing for IAM User
2
20.AWS Access Key Leaked Warning
21-30: RDS, DynamoDB & Database Issues
21.RDS Instance Not Connecting
22.RDS High CPU Utilization
23.RDS Automatic Backup Not Working
24.RDS Connection Timeout from Lambda
25.RDS Read Replica Lagging Behind Primary
26.DynamoDB Query Performance Slower Than Expected
27.DynamoDB Throttling Errors (ProvisionedThroughputExceededException)
28.DynamoDB Streams Not Triggering Lambda
29.DynamoDB Backup Failing
30.RDS Storage Full Error
31-40: AWS Lambda, API Gateway, and CloudFront Issues
31.AWS Lambda Timeout Error
32.Lambda Function Exceeds Memory Limit
33.API Gateway Returning 500 Internal Server Error
34.API Gateway CORS Issues
35.Lambda Cold Start Delays Performance
36.CloudFront Not Serving Updated Content
37.CloudFront Distribution Deployment Stuck in Progress
38.API Gateway Route Not Matching Requests
39.AWS Lambda Not Triggering from S3 Event
, 40.API Gateway Throttling Requests
41-50: AWS CI/CD, Security, and Miscellaneous Issues
41.AWS CodePipeline Stuck in Progress
42.CodeBuild Failing Due to Dependency Errors
3
43.CodeDeploy Failing on EC2 Instances
44.CodeCommit Repository Not Allowing Push
45.CodePipeline Failing Due to S3 Permissions
46.AWS Secrets Manager Not Rotating Credentials
47.AWS Certificate Manager (ACM) Certificate Not Issuing
48.AWS WAF Blocking Legitimate Traffic
49.CloudFormation Stack Failing to Create
50.AWS Auto Scaling Terminating Instances Unexpectedly
51-60: AWS Networking Issues
51.VPC Peering Not Working
52.EC2 Instance Can’t Reach Internet via NAT Gateway
53.Security Group Rules Not Applying Correctly
54.NACL Blocking Expected Traffic
55.VPN Connection Dropping Frequently
56.Direct Connect Latency Higher Than Expected
57.PrivateLink Endpoint Not Working
58.Route 53 DNS Resolution Failing
59.Route 53 Latency-Based Routing Not Working
60.AWS Global Accelerator Not Distributing Traffic Properly
61-70: AWS ECS, EKS, and Container Issues
, DevOps Shack
AWS DevOps Troubleshooting Guide
Table of Contents
1-10: EC2 & Load Balancer Issues
1. EC2 Instance Not Starting
2. EC2 Instance Stuck in “Initializing” State
3. EC2 Instance High CPU Utilization
4. EC2 Instance Unable to Reach the Internet
5. EC2 Instance Connection Timeout (SSH Issues)
6. Elastic Load Balancer (ELB) Not Routing Traffic
7. Target Group in ELB Showing Unhealthy Instances
8. SSL Certificate Not Working on ELB
9. EC2 Auto Scaling Not Launching New Instances
10.EC2 Spot Instance Interrupted Unexpectedly
11-20: S3, IAM, and Permissions Issues
11.S3 Bucket Access Denied (403 Error)
12.S3 Public Access Block Preventing Access
13.S3 Lifecycle Policy Not Deleting Objects
14.S3 Cross-Region Replication Not Working
15.S3 File Upload Extremely Slow
16.IAM Policy Not Granting Expected Access
17.IAM Role Not Attaching to EC2 Instance
, 18.AWS STS Token Expired Error
19.MFA Authentication Failing for IAM User
2
20.AWS Access Key Leaked Warning
21-30: RDS, DynamoDB & Database Issues
21.RDS Instance Not Connecting
22.RDS High CPU Utilization
23.RDS Automatic Backup Not Working
24.RDS Connection Timeout from Lambda
25.RDS Read Replica Lagging Behind Primary
26.DynamoDB Query Performance Slower Than Expected
27.DynamoDB Throttling Errors (ProvisionedThroughputExceededException)
28.DynamoDB Streams Not Triggering Lambda
29.DynamoDB Backup Failing
30.RDS Storage Full Error
31-40: AWS Lambda, API Gateway, and CloudFront Issues
31.AWS Lambda Timeout Error
32.Lambda Function Exceeds Memory Limit
33.API Gateway Returning 500 Internal Server Error
34.API Gateway CORS Issues
35.Lambda Cold Start Delays Performance
36.CloudFront Not Serving Updated Content
37.CloudFront Distribution Deployment Stuck in Progress
38.API Gateway Route Not Matching Requests
39.AWS Lambda Not Triggering from S3 Event
, 40.API Gateway Throttling Requests
41-50: AWS CI/CD, Security, and Miscellaneous Issues
41.AWS CodePipeline Stuck in Progress
42.CodeBuild Failing Due to Dependency Errors
3
43.CodeDeploy Failing on EC2 Instances
44.CodeCommit Repository Not Allowing Push
45.CodePipeline Failing Due to S3 Permissions
46.AWS Secrets Manager Not Rotating Credentials
47.AWS Certificate Manager (ACM) Certificate Not Issuing
48.AWS WAF Blocking Legitimate Traffic
49.CloudFormation Stack Failing to Create
50.AWS Auto Scaling Terminating Instances Unexpectedly
51-60: AWS Networking Issues
51.VPC Peering Not Working
52.EC2 Instance Can’t Reach Internet via NAT Gateway
53.Security Group Rules Not Applying Correctly
54.NACL Blocking Expected Traffic
55.VPN Connection Dropping Frequently
56.Direct Connect Latency Higher Than Expected
57.PrivateLink Endpoint Not Working
58.Route 53 DNS Resolution Failing
59.Route 53 Latency-Based Routing Not Working
60.AWS Global Accelerator Not Distributing Traffic Properly
61-70: AWS ECS, EKS, and Container Issues
