Revision of last five classes

• We have started our discussion with relational databases
• Different ways of creating Databases in AWS
  • IAAS approach:
    • Creating an ec2 instance with necessary os
    • install database management system (mysql, postgres, oracle, db2, microsoft sql server)
    • Import data and use it
  • PAAS approach:
    • AWS has a service called as RDS (Relational Database Services) which helps in creating
      • mysql
      • mariadb
      • postgres
      • sql server
      • oracle
    • In this case we just need to manage the data import and data inside database
• Databases are created in VPC’s. AWS allows users to create db subnet group to select the subnets where db can be launched
• AWS also allows users to create a db security group which acts as firewall around database
• Databases in RDS can be
  • Multi-AZ
  • Single-AZ
• AWS RDS allows us to create read replica of the rds instance in the same region or in different region.
• AWS RDS read replica can be promoted to become primary database where the write operations also will be allowed.
• Backups of the AWS RDS can be selected by choosing the retention period. Backups are referred as snapshots.
• AWS RDS offers two kinds of connectivities
  • Publicly accesible
  • Private connectivity
• SSH Tunneling connections are also available
• When we create dbs we need to select the instance class
  • Standard
  • Memory Optimized
  • Burstable
• Storage:
  • Three storage types
    • General purpose ssd
    • provisioned iops
    • Magnetic (standard)
  • Limitations:
    • upto 64 TiB for mysql, maria db, oracle and postgres
    • upto 16 TiB for Microsoft SQl Server
• Purchasing Options
  • On-demand:
    • No-Commitments
    • Will be charge as you use hourly
    • Costlier option
  • Reservered
    • 1-year or 3-year commitment with AWS
    • Suitable for production workloads
    • Will recieve discount upto 59%

Backups of RDS Databases

• Backup options while creating an rds instance
• Create an rds instance with any db engine (mysql) with 7 days of backup
• In this case aws will automatically take backups
• Users can also initiate on-demand backups
• Once the Snapshot is created, we can copy snapshot, share snapshot, export the snapshot to s3 bucket
• From snapshot we can create a database by restoring snapshot.
• Snapshots are the better way to share data in databases with other AWS Users