Lock contention is a common performance bottleneck in Aurora PostgreSQL. Amazon CloudWatch Database Insights Advanced Mode offers a lock tree analysis feature that provides hierarchical visualizations of blocking and waiting sessions, capturing snapshots every 15 seconds and retaining data for 15 months. Two real-world scenarios are walked through: an e-commerce order processing deadlock during a Black Friday surge, and a telecom billing module stuck in idle-in-transaction state. Both cases demonstrate how to identify root blockers using the lock tree, interpret ClientRead and TransactionId wait events, and resolve issues with pg_terminate_backend(). Best practices cover application design (explicit transaction boundaries, short transactions), database configuration (idle_in_transaction_session_timeout, lock_timeout), and monitoring with pg_stat_activity and pg_locks.
