Troubleshoot AWS Advanced JDBC Wrapper configuration for Aurora Global Database write forwarding

This article explains how to correctly configure the AWS Advanced JDBC Wrapper for Aurora Global Database with write forwarding, addressing misconfigurations that cause 5-second delays and connection failures in secondary Regions.

• Use dialect `global-aurora-mysql` instead of `aurora-mysql` to enable Global Database topology discovery in secondary Regions
• Configure host patterns in instance endpoint format (no `cluster-` prefix) with unique instance names across all Regions
• Use `gdbFailover` plugin instead of `failover2` for Global Database-aware failover with home-Region support
• Set `aurora_replica_read_consistency` to `SESSION` or `GLOBAL` in every forwarding session to enable write forwarding
• Size connection pools under the `aurora_fwd_writer_max_connections_pct` ceiling (default 10% of writer's max_connections)
• For deployments without VPC peering, restrict monitoring with `gdbAccessibleRegions` and `gdbMonitoringConnectionPriority`
• Write forwarding supports only `REPEATABLE READ` isolation and prohibits savepoints, XA transactions, and DDL operations

Correct configuration eliminates topology resolution failures and enables transparent DML routing from secondary Regions to the primary writer, with expected cross-Region latency of 12-15ms per statement.