Sometimes I felt not connected to the session. Needs a lot of focus and patience to stay connected and focused :)
Key Summary points
Key Summary points
- Amazon early offering EC2
- Rented out VMs to customers
- VMM (Virtual Machine Monitors) that run/manage EC2 instances
- EC2 good for stateless web servers
- S3 - Scheme for storing large chunks of data (Periodic Snapshots)
- Disks for EC2 instances - Fault Tolerance (EBS)
- EBS (Elastic Block Store) - Looks for EC2 instances as it is a harddrive
- Databases on EBS sends a large volume of data over the network
- Amount of writes on Network Storage System
- CPU / Disk space consumption
- EC2 / EBS are in same availability zone
- Transaction & Crash Recovery
- Transaction (Sequence of operations / commands / atomic / ex- bank transfer money between accounts)
- Reads page from disk
- Make Changes in local cache
- Then write changes to disk
- Log entries describe the transaction
- Three log records - Modify Operation, Old Value, New Value
- Aurora is based on MySQL
- RDS (Database replicated in multiple availability zones)
- All the transactions mirrored to other databases (EBS Servers)
- Multiple copies managed and updated to keep everything in sync
- Read / Write Quorum will overlap
- Voting does not work to read from which server
- These systems have version numbers
- Readers takes the ones with highest version number
- Split database into replicas
- Data Sharding
- Data across protection groups
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