Best Practices

Recommended setup

Whitelist IPs before connecting

Add Coupler.io's IPs (52.21.222.113 and 35.170.113.181) to your firewall or security group before you create a data flow. This prevents "connection refused" errors and saves troubleshooting time.

Use a dedicated database user

Create a MySQL user specifically for Coupler.io with SELECT-only permissions. This limits the blast radius if credentials are ever compromised and makes audit logs cleaner.

Test with a small table first

Before exporting your largest or most critical table, test the connection with a smaller table to confirm everything works smoothly.

Data refresh and scheduling

Filter by date for large tables

If exporting millions of rows, apply a date filter (e.g., last 30 days) instead of exporting all history. This speeds up exports and reduces timeout risk. You can append historical data in a separate flow if needed.

Start with daily refreshes

Run a daily schedule first to ensure exports complete reliably. Once confident, increase frequency to hourly if your business requires real-time data.

Monitor your first few runs

After scheduling a data flow, check your destination (Google Sheets, BigQuery, etc.) to confirm data is arriving correctly and in the expected format before moving on.

Performance optimization

Index your filtered columns

If filtering on created_at, status, or user_id, ensure those columns have database indexes. This dramatically speeds up query execution and prevents timeouts.

Export views, not complex queries

If you need complex transformations, create a MySQL view and export that instead of filtering in Coupler.io. Views are pre-computed and run faster.

Common pitfalls

Do

• Whitelist IPs in your firewall or security group before connecting

• Create a dedicated MySQL user with SELECT-only permissions

• Apply date filters to large tables to avoid timeouts

• Test your first export with a manual run before scheduling

• Use indexes on columns you filter by (created_at, status, user_id)

Don't

• Use your root or admin MySQL account — create a separate user

• Export your entire database history in one flow if it's millions of rows

• Skip firewall configuration if your database is in the cloud or behind a corporate network

• Schedule very high frequency refreshes (hourly) for large tables without testing first

• Store your MySQL password in plain text notes; use a password manager