crowd-funder-for-time-pwa/docs/DATABASE_CONNECTION_FIXES.md

Database Connection Fixes for TimeSafari

Overview

This document outlines the fixes implemented to resolve database connection issues in the TimeSafari application, particularly for Capacitor SQLite on Android devices.

Issues Identified

1. CapacitorSQLitePlugin Errors

• Multiple *** ERROR CapacitorSQLitePlugin: null messages in Android logs
• Database connection conflicts and initialization failures
• Connection leaks causing "Connection timesafari.sqlite already exists" errors

2. Performance Issues

• App skipping 57 frames due to main thread blocking
• Null pointer exceptions in garbage collection
• Memory management issues

3. Connection Management

• Lack of proper connection cleanup on app lifecycle events
• No retry logic for failed connections
• Missing error handling and recovery mechanisms

Implemented Fixes

1. Enhanced Database Initialization

Connection Cleanup

• Added cleanupExistingConnections() method to properly close existing connections
• Implemented connection consistency checks before creating new connections
• Added proper error handling for connection cleanup failures

Retry Logic

• Implemented exponential backoff retry mechanism for database connections
• Maximum of 3 retry attempts with increasing delays
• Comprehensive error logging for each attempt

Database Configuration

• Configured optimal SQLite settings for performance and stability:
  • PRAGMA journal_mode=WAL for better concurrency
  • PRAGMA synchronous=NORMAL for balanced performance
  • PRAGMA cache_size=10000 for improved caching
  • PRAGMA temp_store=MEMORY for faster temporary operations
  • PRAGMA mmap_size=268435456 (256MB) for memory mapping

2. Lifecycle Management

App Lifecycle Listeners

• Added event listeners for beforeunload and visibilitychange
• Automatic database cleanup when app goes to background
• Proper resource management to prevent connection leaks

Health Monitoring

• Implemented healthCheck() method for connection status monitoring
• Added reinitializeDatabase() for forced reconnection
• Performance metrics tracking for database operations

3. Error Handling and Diagnostics

Comprehensive Error Handling

• Enhanced error logging with detailed context
• Graceful degradation when database operations fail
• User-friendly error messages with recovery suggestions

Diagnostic Tools

• Created databaseDiagnostics.ts utility for troubleshooting
• Database stress testing capabilities
• Performance monitoring and reporting
• System information collection for debugging

4. Configuration Changes

Capacitor Configuration

• Temporarily disabled encryption to isolate connection issues
• Disabled biometric authentication to reduce complexity
• Maintained proper database location settings

Camera Integration Fixes

• Fixed CameraDirection enum usage for Capacitor Camera v6
• Updated from string literals to proper enum values
• Resolved TypeScript compilation errors

Usage

Running Diagnostics

import { runDatabaseDiagnostics, stressTestDatabase } from '@/utils/databaseDiagnostics';

// Run comprehensive diagnostics
const diagnosticInfo = await runDatabaseDiagnostics();
console.log('Database status:', diagnosticInfo.connectionStatus);

// Run stress test
await stressTestDatabase(20);

Health Checks

import { PlatformServiceFactory } from '@/services/PlatformServiceFactory';

const platformService = PlatformServiceFactory.getInstance();
const health = await platformService.healthCheck();

if (!health.healthy) {
  console.error('Database health check failed:', health.error);
  // Attempt reinitialization
  await platformService.reinitializeDatabase();
}

Performance Monitoring

import { logDatabasePerformance } from '@/utils/databaseDiagnostics';

// Wrap database operations with performance monitoring
const start = Date.now();
await platformService.dbQuery("SELECT * FROM users");
const duration = Date.now() - start;
logDatabasePerformance("User query", duration);

Troubleshooting Guide

Common Issues and Solutions

1. "Connection timesafari.sqlite already exists"

Cause: Multiple database connections not properly closed Solution:

• Use the enhanced cleanup methods
• Check for existing connections before creating new ones
• Implement proper app lifecycle management

2. CapacitorSQLitePlugin null errors

Cause: Database initialization failures or connection conflicts Solution:

• Use retry logic with exponential backoff
• Check connection consistency
• Verify database configuration settings

3. Performance Issues

Cause: Main thread blocking or inefficient database operations Solution:

• Use WAL journal mode for better concurrency
• Implement proper connection pooling
• Monitor and optimize query performance

4. Memory Leaks

Cause: Database connections not properly closed Solution:

• Implement proper cleanup on app lifecycle events
• Use health checks to monitor connection status
• Force reinitialization when issues are detected

Debugging Steps

1. Check Logs: Look for database-related error messages
2. Run Diagnostics: Use runDatabaseDiagnostics() to get system status
3. Monitor Performance: Track query execution times
4. Test Connections: Use stress testing to identify issues
5. Verify Configuration: Check Capacitor and SQLite settings

Recovery Procedures

Automatic Recovery

• Health checks run periodically
• Automatic reinitialization on connection failures
• Graceful degradation for non-critical operations

Manual Recovery

• Force app restart to clear all connections
• Clear app data if persistent issues occur
• Check device storage and permissions

Security Considerations

Data Protection

• Encryption can be re-enabled once connection issues are resolved
• Biometric authentication can be restored after stability is confirmed
• Proper error handling prevents data corruption

Privacy

• Diagnostic information is logged locally only
• No sensitive data is exposed in error messages
• User data remains protected during recovery procedures

Performance Impact

Improvements

• Reduced connection initialization time
• Better memory usage through proper cleanup
• Improved app responsiveness with background processing
• Enhanced error recovery reduces user impact

Monitoring

• Performance metrics are tracked automatically
• Slow operations are logged with warnings
• System resource usage is monitored

Future Enhancements

Planned Improvements

1. Connection Pooling: Implement proper connection pooling for better performance
2. Encryption Re-enablement: Restore encryption once stability is confirmed
3. Advanced Monitoring: Add real-time performance dashboards
4. Automated Recovery: Implement self-healing mechanisms

Research Areas

1. Alternative Storage: Investigate other storage solutions for specific use cases
2. Migration Tools: Develop tools for seamless data migration
3. Cross-Platform Optimization: Optimize for different device capabilities

Conclusion

These fixes address the core database connection issues while maintaining application stability and user experience. The enhanced error handling, monitoring, and recovery mechanisms provide a robust foundation for reliable database operations across all platforms.

Author

Matthew Raymer - Database Architecture and Mobile Platform Development