aws-cloud-tools

RDS Commands

The RDS command group provides tools for managing and troubleshooting Amazon RDS instances, with specialized support for MySQL connection issues.

Commands

troubleshoot-mysql

Analyze MySQL RDS instances for connection-related issues, including the common “too many connections” error.

aws-cloud-utilities rds troubleshoot-mysql <DB_INSTANCE_IDENTIFIER> [OPTIONS]

Arguments

• DB_INSTANCE_IDENTIFIER: The RDS instance identifier to troubleshoot

Options

• --output-file FILE: Save detailed results to a JSON file
• --profile PROFILE: AWS profile to use
• --region REGION: AWS region
• --output FORMAT: Output format (table, json, yaml, csv)

Examples

# Basic troubleshooting
aws-cloud-utilities rds troubleshoot-mysql my-mysql-db

# Save detailed results to file
aws-cloud-utilities rds troubleshoot-mysql my-mysql-db --output-file mysql-analysis.json

# Use specific profile and region
aws-cloud-utilities rds troubleshoot-mysql my-mysql-db --profile production --region us-west-2

What it analyzes

1. Instance Information
   • Instance class and specifications
   • Engine version and status
   • Multi-AZ configuration
   • Performance Insights status
2. Connection Metrics (Last 24 Hours)
   • Database connections (current and peak)
   • Connection attempts
   • Aborted connections
   • Thread statistics
3. Parameter Groups
   • Connection-related parameters
   • Current values and sources
   • Modifiable parameters
4. Error Logs
   • Recent connection-related errors
   • “Too many connections” occurrences
   • Connection timeouts and resets
5. Recommendations
   • Prioritized action items
   • Configuration suggestions
   • Best practice recommendations

list-instances

List RDS instances in the current region with optional filtering.

aws-cloud-utilities rds list-instances [OPTIONS]

Options

• --engine ENGINE: Filter by database engine (mysql, postgres, etc.)
• --status STATUS: Filter by instance status (available, stopped, etc.)

Examples

# List all RDS instances
aws-cloud-utilities rds list-instances

# List only MySQL instances
aws-cloud-utilities rds list-instances --engine mysql

# List only available instances
aws-cloud-utilities rds list-instances --status available

Common MySQL Connection Issues

Too Many Connections Error

This error occurs when the number of concurrent connections exceeds the max_connections parameter value.

Common causes:

• Application not using connection pooling
• Connection leaks in application code
• Insufficient max_connections setting
• High traffic without proper scaling

Solutions:

1. Implement connection pooling in your application
2. Increase max_connections parameter
3. Upgrade to a larger instance class
4. Use read replicas to distribute load
5. Fix connection leaks in application code

High Aborted Connections

Indicates connections being terminated unexpectedly.

Common causes:

• Network timeouts
• Application connection handling issues
• Security group or firewall issues
• Client-side connection drops

Solutions:

1. Check network connectivity
2. Review application connection handling
3. Adjust timeout parameters
4. Monitor security group rules

Parameter Tuning

Key Connection Parameters

• max_connections: Maximum number of concurrent connections
• connect_timeout: Connection establishment timeout
• wait_timeout: Time to wait for activity on a connection
• interactive_timeout: Timeout for interactive connections
• thread_cache_size: Number of threads to cache for reuse

Best Practices

1. Connection Pooling: Always use connection pooling in applications
2. Right-sizing: Choose appropriate instance classes for your workload
3. Monitoring: Set up CloudWatch alarms for connection metrics
4. Read Replicas: Use read replicas to distribute read traffic
5. Parameter Groups: Create custom parameter groups for production workloads

Monitoring and Alerting

Recommended CloudWatch Alarms

# Database connections approaching limit
DatabaseConnections > 80% of max_connections

# High aborted connections
AbortedConnections > 10 per 5 minutes

# High connection attempts
ConnectionAttempts > normal baseline + 50%

Performance Insights

Enable Performance Insights for detailed analysis of:

• Top SQL statements
• Wait events
• Database load
• Connection patterns

Troubleshooting Workflow

1. Run the troubleshoot command

   aws-cloud-utilities rds troubleshoot-mysql your-db-instance
   

2. Review the analysis results
   • Check current connection metrics
   • Look for error patterns in logs
   • Review parameter configurations
3. Implement recommendations
   • Start with high-priority items
   • Test changes in non-production first
   • Monitor impact of changes
4. Follow up monitoring
   • Set up CloudWatch alarms
   • Enable Performance Insights
   • Regular health checks

Integration with Other Tools

The RDS troubleshooting tool integrates with:

• CloudWatch metrics and logs
• Performance Insights (when enabled)
• Parameter groups
• Security groups (via instance info)

Output Formats

Table Format (Default)

Provides a clean, readable summary with color-coded recommendations.

JSON Format

Detailed machine-readable output suitable for automation and further analysis.

File Output

Save complete analysis results to a JSON file for:

• Historical tracking
• Sharing with team members
• Integration with other tools
• Compliance documentation

Security Considerations

• The tool only reads RDS configuration and metrics
• No sensitive data is displayed in output
• Uses your existing AWS credentials and permissions
• Follows AWS IAM best practices

Required Permissions

{
    "Version": "2012-10-17",
    "Statement": [
        {
            "Effect": "Allow",
            "Action": [
                "rds:DescribeDBInstances",
                "rds:DescribeDBParameters",
                "rds:DescribeDBLogFiles",
                "rds:DownloadDBLogFilePortion",
                "cloudwatch:GetMetricStatistics"
            ],
            "Resource": "*"
        }
    ]
}