Storage and Databases Flashcards
What is an Instance Store?
Provides temporary block-level storage for an EC2 instance and behave like physical hard drives
An instance store is disk storage attached to the host computer for an EC2 instance
When the EC2 instance is terminated, you lose any data in the instance store
Useful in situations when you can afford to lose the data when its terminated
What is Elastic Block Store? (EBS)
Provides block-level storage volumes that you can use with EC2 instances
Data on the EBS remains available when an EC2 instance is stopped or terminated
EBS volumes are configured (volume and size), provisioned and attach to EC2 instance
EBS volumes are for data that needs to persist, so its important to back up the data
What are EBS Snapshots?
an be used to take incremental backups of EBS volumes
Incremental means each backups saves only the data changed from the last backup.
A full backup is an overwrite, backing up even the data that hasn’t changed
What is Amazon Simples Storage Service? (Amazon S3)
Provides object-level storage.
Each object consists of data, metadata & a key
E.g. image, txt doc. Metadata contains info on the data and they key is its identifier
S3 stores data as objects in buckets, has unlimited storage space with max file size of 5TB
You can set permissions to control visibility and access & use versioning to track changes
What are the S3 Storage classes?
- S3 Standard
Highly durable and used for frequently accessed data
Stores data in a min of 3 AZs
Good for websites, content distribution, and data analytics
- S3 Standard-Infrequent
Access (S3 Standard IA)
Ideal for infrequently access data but required rapid access when needed
Stores data in a min of 3 AZs and used for backups, disaster recovery files
Same availability as S3 Standard but with a lower storage price & a higher retrieval price
- S3 One Zone IA
Stores data in a single AZ and has a lower storage price than standard IA
Good to save costs and if you can easily reproduce your data in the event of AZ failure
- S3 Intelligent Tiering
Ideal for data with unknown or changing access patterns
Requires small monthly monitoring and automation fee per object
If an object hasn’t been accessed for 30 days, it gets auto moved to standard IA
- S3 Glacier
Low-cost storage for data archiving
Good for compliance requirements to retain customer records for several years
Objects are retrievable with a few minutes to hours
- S3 Glacier Deep Archive
Lower cost than glacier as retrieval can take up to 12 hours
If using complete data with occasional change, S3. If using complex read/write change functions, EBS
What is Amazon Elastic File System? (EFS)
A scalable file system used with AWS cloud services and on-prem resources
Stores data in and across multiple AZs enabling concurrent access
As you add/remove files, EFS shrinks and grows automatically and can scale to petabytes
On-prem servers can access EFS using AWS direct connect
What are Relational Databases?
Data is stored in a way that relates to other pieces of data
E.g. product name, size and price for a single item
Use structured query language (SQL) to store and query data
E.g. coffee shop owners can write SQL query to identify customers who most often buy a latte
What is Amazon Relational Database Service? (Amazon RDS)
Used to run relational databases in the AWS cloud
Automates tasks like hardware provisioning, database setup, patching and backups. Enables less time for admin and more time using data to innovate apps
Can be integrated with other services like Lambda to query database from a serverless app
Offers encryption at rest (while data is stored) and encryption in transit (while its sent and rec)
What database engines is RDS available on?
Amazon Aurora
PostgreSQL
MySQL
MariaDB
Oracle Database
Microsoft SQL Server
What are non relational Databases?
You create tables. A table is a place you can store and query your data
Sometimes called ‘No SQL databases’
Uses key value pairs. Keys = items, Value = attributes
What is Amazon DynamoDB?
A key-value database where you create tables
Serverless so don’t provision/patch/manage servers or install/maintain/operate software
Delivers fast performance at any scale and auto-scales capacity when database shrinks/grows
For complex relationships, use RDS. For lighter use cases, use DynamoDB
What is Amazon Redshift?
A data warehouse used for big data analytics
Helps collect data from many sources to help understand relationships and trends across data
What is Amazon Data Migration Service? (AWS DMS)
Used to migrate different types of databases
Source database remains operational to reduce downtime for apps
Moves data between source database and target database (even if they’re different)
Homogenous migrations = same source and target
Heterogenous migrations = different source and target type (diff schema, data types and code)
Conversion tool is used to convert schema and code to target format
What are the additional DB services?
Amazon Document DB
Document database service that supports MongoDB workloads
Good for content management, catalogues, user profiles
Amazon Neptune
Graph database service
Good for social networks, recommendation engines, fraud detection, and knowledge graphs.
Amazon Quantum Ledger Database (QLDB)
Ledger database service
Has complete history of all changes that have been made for app data. Entries never removed
Amazon Managed Blockchain
Create and manage blockchain networks with open-source framework
Amazon ElastiCache
Adds caching layers on top of your databases to improve the read times of common requests
Amazon DynamoDB Accelerator
An in-memory cache for DynamoDB. Improves response times
