[AWS] 4-2. Aurora

[ Aurora ]

- Aurora is a proprietary technology from AWS (not open sourced)

- Postgres and MySQL are both supported as Aurora DB (that means your drivers will work as if Aurora was a Postgres or MySQL database)

- Aurora is "AWS cloud optimized" and claims 5x performance improvement over MySQL on RDS, over 3x the - performance of Postgres on RDS

- Aurora storage automatically grows in increments of 10GB, up to 64TB

- Aurora can have 15 replicas while MySQL has 5, and the replication process is faster (sub 10ms replica lag)

- Failover in Aurora is instantaneous(즉각적인). It's High Availability native

- Aurora costs more than RDS(20% more) - but is more efficient

 

# Aurora High Availability and Read Scaling

- 6 copies of your data across 3 AZ :

  -- 4 copies out of 6 needed for writes

  -- 3 copies out of 6 need for reads

  -- Self healing with peer-to-peer replication

  -- Storage is striped across 100s of volumes

- One Aurora Instance takes writes (master)

- Automated failover for master in less than 30 seconds

- Master + up to 15 Aurora Read Replicas serve reads

- Support for Cross Region Replication

 

 

[ Aurora DB Cluster ]

쓰기(Master를 통해)와 읽기(Read Replicas를 통해)는 각각의 endpoint 를 통해 수행

[ Aurora Security ]

- Similar to RDS because uses the same engines

- Encryption at rest using KMS

- Automated backups, snapshots and replicas are also encrypted

- Encryption in flight using SSL (same process as MySQL or Postgres)

- Possibility to authenticate using IAM token (same method as RDS)

- You are responsible for protecting the instance with security groups

- You can't SSH

 

[ Aurora Serverless ]

로드량이 많아지면 Aurora database 가 추가적으로 생성됨. 반대로 적어지면 줄어듬

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

- Good for infrequent, intermittent(간헐적인) or unpredictable workloads

- No capacity planning needed

- Pay per second, can be more cost-effective

 

[ Global Aurora ]

1개의 마스터 region, 최대 5개의 서브 region, region 당 최대 16개의 read replicas

- Aurora Cross Region Read Replicas :

  Useful for disaster recovery

  Simple to put in place

- Aurora Global Database (recommended) :

  1 Primary Region (read/write)

  Up to 5 secondary (read-only) regions, replication lag is less then 1 second

  Up to 16 Read Replicas per secondary region

  Helps for decreasing latency

  Promoting another region (for disaster recovery) has an RTO(recovery time object) of < 1 minute