I am not able to upload and process images or pdf in permissible sizes neither directly from my PC nor from redshift.

It sounds like you're experiencing issues with file uploads to AWS services. Let me help troubleshoot this problem.

For slow or failing uploads from your PC to S3, there are several potential causes and solutions:

1. Network performance: S3 upload speeds can sometimes be slower than expected. You can improve this by:

• Using Amazon S3 Transfer Acceleration which optimizes transfers using AWS edge locations
• Implementing multipart uploads for large files, which allows parallel uploading of file parts
• Adjusting AWS CLI configuration parameters if you're using the CLI:
• Increase concurrent requests (e.g., set max_concurrent_requests to 16)
• Increase queue size (e.g., set max_queue_size to 10000)
• Set appropriate multipart threshold and chunk size (e.g., 64MB)

2. File size limitations: While S3 itself supports files up to 5TB, there might be limitations in:

• Your application code or libraries that impose size limits
• Web interfaces with client-side JavaScript limitations
• AWS WAF rules that might be limiting request body size (by default, WAF only inspects the first 16KB)
• API Gateway settings if you're using it in your upload process

3. For issues with Redshift specifically:

• Ensure your Redshift cluster has the necessary permissions to access the S3 bucket
• Check if there are any VPC or security group configurations blocking the connection
• Verify that the IAM roles associated with your Redshift cluster have the appropriate permissions

4. General troubleshooting steps:

• Try uploading smaller files to see if the issue is size-related
• Check your browser console for any specific error messages
• Try a different browser or network connection
• Use the AWS CLI to upload files as an alternative method
• Ensure your AWS credentials are properly configured

If you continue to experience issues after trying these solutions, you may need to contact AWS Support for more specific assistance with your account configuration.
Sources
Upload to AWS S3 is pathetically slow | AWS re:Post
S3 Upload Limit of 1MB – How to Fix? | AWS re:Post
Unable to upload files to my S3 management console | AWS re:Post