You're facing database performance issues during peak traffic. How can you efficiently troubleshoot them?

Having a good monitoring system and a query analysis tool is key to identify slow queries. If that's not set you must go to the logs and identify slow queries. Then make an action plan to implement changes needed to speed up those queries. This should include, possible index creation, query rewriting, redirecting queries to secondaries among others. Always test every change in an isolated environment before applying in production and schedule a maintenance window to apply them. after the changes are applied carefully monitor the system to see if the changes help and be prepared to rollback in case it didn't.