Build zero-downtime write architectures for Amazon Neptune

This article describes the write queue architecture pattern for Amazon Neptune that decouples write acceptance from execution using SQS, Kinesis, or MSK to maintain availability during maintenance and failover events.

• Place a durable message queue between applications and Neptune to accept writes during unavailability
• Understand causes of Neptune write downtime: parameter changes, scaling, failover, patching, and regional events
• Choose between SQS Standard (unordered), SQS FIFO (ordered), Kinesis Data Streams (replay), or MSK (high throughput)
• Design idempotent writes using Gremlin mergeV()/mergeE() or openCypher MERGE to handle duplicate deliveries
• Implement ordering with SQS FIFO message group IDs or Kinesis partition keys when dependencies exist
• Monitor queue depth, message age, and consumer lag with CloudWatch alarms and dead-letter queues
• Handle read-after-write consistency via caching, dual-path writes, or accepting eventual consistency
• Deploy write queues in each region for multi-region architectures with Neptune global databases

The write queue pattern trades immediate consistency for high availability, enabling applications to accept writes continuously even when Neptune is temporarily unavailable.