Resilience in Amazon QLDB - Amazon Quantum Ledger Database (Amazon QLDB)

Resilience in Amazon QLDB

The AWS global infrastructure is built around AWS Regions and Availability Zones. AWS Regions provide multiple physically separated and isolated Availability Zones, which are connected with low-latency, high-throughput, and highly redundant networking. With Availability Zones, you can design and operate applications and databases that automatically fail over between Availability Zones without interruption. Availability Zones are more highly available, fault tolerant, and scalable than traditional single or multiple data center infrastructures.

For more information about AWS Regions and Availability Zones, see AWS Global Infrastructure.

Storage durability

QLDB journal storage features synchronous replication to multiple Availability Zones on transaction commits. This ensures that even a full Availability Zone failure of journal storage would not compromise data integrity or the ability to maintain an active service. Additionally, the QLDB journal features asynchronous archives to fault-tolerant storage. This feature supports disaster recovery in the highly unlikely event of simultaneous storage failure for multiple Availability Zones.

QLDB indexed storage is backed by replication to multiple Availability Zones. This ensures that even a full Availability Zone failure of indexed storage would not compromise data integrity or the ability to maintain an active service.

Data durability features

In addition to the AWS global infrastructure, QLDB offers the following features to help support your data resiliency and backup needs.

QLDB service features

On-demand journal export

QLDB provides an on-demand journal export feature. Access the contents of your journal by exporting journal blocks from your ledger into an Amazon Simple Storage Service (Amazon S3) bucket. You can use this data for various purposes such as data retention, analytics, and auditing. For more information, see Exporting journal data from Amazon QLDB.

Backup and restore

Automated restore for exports is not supported at this time. Export provides a basic ability to create additional data redundancy at your defined frequency. However, a restore scenario is application dependent, where the exported records are presumably written back to a new ledger by leveraging the same or similar ingestion method.

QLDB does not provide a dedicated backup and related restore feature at this time.

Journal streams

QLDB also provides a continuous journal stream capability. You can integrate QLDB journal streams with the Amazon Kinesis streaming platform to process real-time journal data. For more information, see Streaming journal data from Amazon QLDB.

QLDB design feature

QLDB is designed to be resilient against logical corruption. The QLDB journal is immutable, ensuring that all committed transactions are persisted to the journal. In addition, every committed document change is recorded, as this enables point-in-time visibility for any unintended changes to ledger data.

QLDB does not provide an automated recovery feature for logical corruption scenarios at this time.