Aurora

Introduction

• A MySQL and PostgreSQL compatible relational database on AWS

• 5x faster than standard MySQL databases and 3x faster than standard PostgreSQL databases.

• Provides the security, availability, and reliability of commercial-grade databases at 1/10 of the cost.

Feature

• Provision Type:

  • Self-Provisioned

    • Starts with 10 GB, scales in 10 GB increments to 64TB automatically

    • Can scale up to 32 CPUs and 244GB of memory

  • Serverless

    • Automated database instantiation and auto-scaling based on actual usage.

• 2 copies of data in each AZ with minimum of 3 AZs (can choose AZ, and have 6 copies at least)

  • 4 copies out of 6 needed for writes

  • 3 copies out of 6 neede for reads

• Read / Write

  • With a write endpoint to write into Master

  • With a read endpoint to read from all Read Replicas (Scalability):

    • Aurora Replica

      • up to 15 Read Replicas

    • MySQL Replica

      • up to 5 Read Replicas

• Cross Region Read Replicas (RR): entire DB is copied (not select tables)

• Import / export data directly from / to S3: efficient use of resources

• Backtracking for rewinding the database status (useful for doing Tests)

  • Point-in-time restoration from snapshots creates a new database. (needs more time)

• Global Aurora (cross region)

  • Aurora Cross Region Read Replicas

    • Useful for DR

    • Simple to put in place

  • Aurora Global Database (recommended)

    • One Primary Region (read / write)

    • Up to 5 secondary (read only) regions, replication lag is lesser than 1 second

    • Up to 16 Read Replicas per secondary region

    • Helpful for decreasing latency

    • Promoting another region (for DR) has an RTO within 1 minute

• Aurora Multi-Master

  • In case you need immediate failover for write node (HA)

  • Every Aurora node can do read / write (need to promote a RR regularly)

  • Limits:

    • The maximum number of nodes: 2.

    • Can only be in one region.

    • May increase latency and deal with conflict with an algorithm.

    • Not support integration with other AWS services.

    • Etc.

• Loss Handling

  • Loss of up to 2 copies of data without affecting write availability

  • Loss of up to 3 copies of data without affecting read availability

  • Self-healing (scanning errors and repairing automatically)