Databases on AWS Flashcards
Name the 6 types of RDS’s in AWS
- SQL Server 2. Oracle 3. My SQL Server 4. PostgreSQL 5. Aurora 6. MariaDB
What are the two key features of RDS?
Multi AZ for DR and Read replicas for performance
Are key value pairs found in RDS or Non Relational DB’s?
Non relational DB’s
What is data warehousing used for?
business intelligence and pulling in very large and complex data sets
What is Amazon’s Data Warehouse Solution called?
Red Shift
What is Amazon’s noSQL DB solution called?
DynamoDB
What do RDS’s run on?
Virtual Machines (EC2 instances)
Who is responsible for patching of RDS’s?
Amazon
True of false: RDS is Serverless
False, with the only exception of Aurora Serverless
What are the two types of backups for RDS?
Automated and Database Snapshots
T or F: Multi AZ for RDS will give you an exact copy of your production DB in another AZ
True
Why use Read Replicas?
It improves performance of your DB
What must you have turned on in order to deploy a read replica?
Automatic backups
Where is DynamoDB stored?
SSD Storage
How many data centers is Dynamo DB spread across?
3
Difference between Eventual Consistent Read and Strongly Consistent Read for DyanmoDB
Eventual means usually read within a second and Strongly is less than a second
What is DynamoDB Accelerator (DAX)
fully managed, highly available, in memory cache. This will reduce request times from milliseconds to microseconds.
Why would a developer want to use DAX?
So they don’t have to manager the caching logic
What are transactions in DynamoDB?
Fulfilling orders. DynamoDB prepares two underlying reads or writes
What are streams in DynamoDB?
time ordered sequence of item level changes in a table
What are shards in DynamoDB?
Groups of stream records.
What allows you to configure data migration logic from one DB to another?
Database Migration Service (DMS)
What is AWS’s data warehousing option?
Redshift
In what two options can you configure Redshift?
Single or multi node
In a multi node configuration in Redshift, what are the types of nodes?
Leader node and Compute Node
Explain leader nodes and compute nodes
Leader manages client connections and receives queries. Compute stores data and perform queries and computation. You can have up to 128 compute nodes
What feature of Redshift allows it to use less space?
Advanced compression
What is the benefit of using Aurora?
relational DB engine that combines speed and availability of high end commercial DB’s
How is Aurora self healing?
data block and disks are continuously scanned for errors and repaired automatically
3 types of Aurora replicas
- Aurora replica (in region, automated failover) 2. MySQL read replica (cross region, no automated failover) 3. PostgresQL
What is Aurora Serverless and when would you use it?
on demand, autoscaling config for MySQL and PostgreSQL compatible editions of Aurora. Used for infrequent or unpredictable workloads
What is Elasticache?
web service for deploying, operating and scaling and in memory cache in the cloud
What are the 2 open source caching engines that are options in Elasticache?
Memcached & Redis
When to use Memcached vs Redis
Memcached - simple and easy to start / Redis - need advanced data type, multi AZ, or ranking and sorting data sets
Types of Data Migration Services (DMS) migrations
- homogenous migrations (DB’s of the same type 2. heterogenous migrations (one type of B to another)
What must you use for heterogenous DMS migrations?
AWS Schema Conversion tool
What is Amazon EMR?
big data platform for processing vast amounts of data using open source tools
What is the central component of Amazon EMR?
The cluster, which is a collection of EC2 instances
What are the node types in Amazon EMR and what do they do?
- Master Node - manages the cluster. Every cluster has one 2. Core Node - Runs tasks and stores data in Hadoop Distributed File System ( HDFS) 3. Task Node - runs tasks but does not store data in HDFS. These are optional
Where is log data stored at by default in Amazon EMR?
The master node
What happens to I/O operations of a single AZ RDS instance during a DB snapshot or backup?
I/O may be briefly suspended while backup process initializes and you may experience brief period of elevated latency
T or F: You can RDP or SSH into an RDS instance
F
T or F: RDS Reserved Instances are available for multi AZ deployments
T
What is the max value for RDS backup retention periods?
35 days
What storage option is recommended if you want to run a DB on an EC2 instance?
EBS
Default port number for MySQL installation
3306
Which AWS DB platform is most suitable for Online Transaction Processing (OLTP)
RDS
Yes or No: Is there a data transfer charge incurred when replicating data from your primary RDS instance to your secondary?
No
T or F: DynamoDB is a non relational DB
T
T or F: When you add a rule to a RDS DB security group, you must specify a port number or protocol
F
