> ## Documentation Index > Fetch the complete documentation index at: https://docs.pylar.ai/llms.txt > Use this file to discover all available pages before exploring further. # Troubleshooting Connections > Common connection issues and solutions for connecting data sources to Pylar ## Overview This guide helps you troubleshoot common issues when connecting data sources to Pylar. Follow these solutions to resolve connection problems quickly. ## Common Connection Issues ### Connection Timeout Errors **Symptoms**: Connection attempts timeout or fail to connect **Common Causes**: * IP address not whitelisted * Firewall blocking connections * Network connectivity issues * Database server not accessible **Solutions**: 1. **Verify IP Whitelisting**: * Ensure Pylar IP `34.122.205.142` is whitelisted * Check firewall rules allow the database port * Verify security group settings (for cloud databases) 2. **Check Network Connectivity**: * Verify database server is running * Test connection from your local machine * Check if database is publicly accessible * Review network routing 3. **Verify Port Configuration**: * Check port number is correct * Ensure port is open in firewall * Verify database is listening on the port ### Authentication Failures **Symptoms**: "Authentication failed" or "Access denied" errors **Common Causes**: * Incorrect username or password * User account locked or disabled * Insufficient permissions * Credentials expired **Solutions**: 1. **Verify Credentials**: * Double-check username spelling * Verify password is correct (no extra spaces) * Test credentials in database client * Reset password if needed 2. **Check User Status**: * Verify user account is active * Check if account is locked * Review user permissions * Ensure user has database access 3. **Review Permissions**: * Verify user has SELECT permissions * Check schema-level permissions * Review table-level access * Grant necessary permissions ### Network Issues **Symptoms**: "Connection refused" or "Network unreachable" errors **Common Causes**: * Database not publicly accessible * VPN or private network restrictions * DNS resolution issues * Network security policies **Solutions**: 1. **Database Accessibility**: * Verify database is publicly accessible * Check if database is in private VPC * Configure network access if needed * Use SSH tunnel for private databases 2. **DNS Issues**: * Verify hostname resolves correctly * Try using IP address instead of hostname * Check DNS configuration * Review network settings 3. **Network Policies**: * Review security group rules * Check firewall configurations * Verify network routing * Review cloud provider network settings ### Permission Errors **Symptoms**: "Permission denied" or "Access denied" when querying **Common Causes**: * User lacks necessary permissions * Database-level restrictions * Schema-level access controls * Table-level permissions **Solutions**: 1. **Grant Permissions**: ```sql theme={null} -- Example for PostgreSQL GRANT SELECT ON schema_name.table_name TO pylar_user; GRANT USAGE ON SCHEMA schema_name TO pylar_user; ``` 2. **Review Access Controls**: * Check database user permissions * Review schema access * Verify table-level permissions * Check row-level security policies 3. **Test Permissions**: * Test queries directly in database * Verify user can access tables * Check for any access restrictions ## Database-Specific Issues ### BigQuery Issues **Issue**: Service account JSON invalid **Solutions**: * Verify JSON is complete and valid * Check service account has proper roles * Ensure JSON key hasn't expired * Regenerate JSON key if needed **Issue**: Project ID not found **Solutions**: * Verify Project ID is correct * Check project exists in Google Cloud * Ensure service account has project access * Review project permissions ### Snowflake Issues **Issue**: Account URL format incorrect **Solutions**: * Remove `https://` prefix * Remove everything after `.snowflakecomputing.com` * Verify account identifier is correct * Check URL format matches requirements **Issue**: Network policy blocking **Solutions**: * Add IP `34.122.205.142` to network policy * Verify network policy is applied * Check account-level network settings * Review user network restrictions ### PostgreSQL/MySQL Issues **Issue**: Connection refused **Solutions**: * Verify database is publicly accessible * Check `pg_hba.conf` or MySQL user hosts * Ensure IP is whitelisted * Review firewall rules **Issue**: Port not accessible **Solutions**: * Verify port number (5432 for PostgreSQL, 3306 for MySQL) * Check firewall allows port * Ensure database is listening on port * Review security group settings ### Redshift Issues **Issue**: Endpoint URL format **Solutions**: * Remove port from endpoint (everything after `:`) * Enter port separately (default 5439) * Verify endpoint format is correct * Check cluster is publicly accessible **Issue**: Security group blocking **Solutions**: * Add IP `34.122.205.142` to security group * Allow Redshift protocol (TCP port 5439) * Verify security group is attached to cluster * Review VPC network settings ## Debugging Tips ### Test Connection Manually Before troubleshooting in Pylar, test the connection manually: **PostgreSQL/MySQL**: ```bash theme={null} psql -h hostname -p port -U username -d database_name # or mysql -h hostname -P port -u username -p database_name ``` **BigQuery**: ```bash theme={null} bq query --use_legacy_sql=false "SELECT 1" ``` ### Check Connection Logs * Review Pylar connection logs * Check database server logs * Review firewall/security group logs * Look for specific error messages ### Verify Network Connectivity ```bash theme={null} # Test if port is accessible telnet hostname port # or nc -zv hostname port ``` ### Test Credentials * Test credentials in database client * Verify credentials work from command line * Check if credentials have necessary permissions ## Getting Help If you've tried troubleshooting and still have issues: 1. **Check Documentation**: Review specific connection guides 2. **Review Error Messages**: Look for specific error codes 3. **Contact Support**: Reach out with: * Connection type * Error message * Steps you've tried * Relevant logs ## Prevention Tips ### Before Connecting * ✅ Verify you have correct credentials * ✅ Check IP whitelisting requirements * ✅ Ensure database is accessible * ✅ Review permission requirements ### After Connecting * ✅ Test connection immediately * ✅ Verify data appears correctly * ✅ Monitor connection health * ✅ Set up alerts for failures ## Next Steps * [Connection Security](/learn/making-connections/connection-security) - Secure your connections * [Managing Connections](/learn/making-connections/managing-connections) - Manage your connections * [SSH Connections](/learn/making-connections/connecting-via-ssh) - Enhanced security option Learn security best practices