Database on AWS Flashcards
What RDS Databases are available?
SQL
MySQL
PostgesSQL
Oracle
Aurora
MariaDB
What is the best DB option for online analytics
Red Shift
You need an RDS database, but do not want to manage the OS. What can you use?
Any RDS, it runs on VMs but you cannot RDP or SSH to them
Is RDS serverless?
No, except for aurora
What are the RDS backup options?
Automated
Manual Snapshots
You need to improve your RDS DB performance. What can you do?
Use read replicas
What are the characteristics of read replicas?
Increases performance
Must have backups turned on
Can be multi-az
Can be in different regions
Can be aurora or MySQL
Can promote RR to master
You promoted a read replica to master, what will break?
replication
Why would you use multi-az RR?
DR
How can you force a multi-az failover?
Reboot one of the instances
What RDS DB’s provide encryption?
MySQL
Oracle
SQL Server
Postgres
MariaDB
Aurora
What encryption service does RDS use?
AWS Key mgmt Service (KMS)
What are the characteristics of DynamoDB?
SSD
Spread across thre geographically distinct data centers
Eventual consistent reads (default)
Strongly consistent reads (available for higher cost)
What is the use case for red shift?
OLAP Data Warehouse for Business Intelligence
Is multi-az available for red shift?
No
What is the maximum retention for red shift backups?
35 days
How many copies does red shift maintain of your data?
three. Original and replica on compute and an S3 backup
What DR options are available for red shift?
asynchronously replicate snapshots to S3 in another region
How many copies of your data are maintained in Aurora?
6 copies. 2 copies in each AZ with a minimum of 3 az’s
What is the use case for RDS?
Online transaction processing
What are the types of elasticache?
memcached
redis
You need data written to a dynamo DB read back within seconds. What option do you choose
Enable strongly consistent reads
What is elasticache?
A cloud-based in-memory cache used by app/web servers to improve database performance for frequently used database calls.
Describe redis
key/value store
master slave architecture
multi az
Describe memcached
Simple, widely adopted, in-memory key/value store for small chunks of arbitrary data from the results of database calls, API calls, or page rendering.
What database service categories are available on AWS?
RDS - (OnLine Transaction Processing, standard Relational Databases)
DynamoDB (NoSQL)
RedShift (OnLine Analytics Processing, Business Intelligence)
Elasticache (in memory caching)
Database Migration Service
What OLTP databases are available in RDS?
MS SQL Server
MySQL
PostgreSQL
Oracle
MariaDB
Aurora
How does Automated Backups work?
Automated Backups allow you to recover your DB to any point in time within a “retention period”. Retention Period can be between 1 and 35 days. Automated Backups will take a full daily snapshot and will also store the transaction logs throughout the day.
What is Multi-AZ RDS?
Multi-AZ allows to have an exact copy of your production database in another AZ. In the event of planned DB maintenance, BD instance failure, or an Availability Zone failure, Amazon RDS will automatically failover to the standby.
What is the use case for Multi-AZ RDS
Multi-AZ is for disaster recovery. It is not used for improving performance. For performance improvement, Read Replicas are needed.
Can Multi-AZ be used to performance improvement?
No. Multi-AZ is for disaster recovery. It is not used for improving performance. For performance improvement, Read Replicas are needed.
What options do you have to improve DB performance
Read replicas and elasticache
What are the maximum number of read replicas?
5
How do read replicas improve performance?
App/web servers can be confiured to use the relica copies to spread out the load
What is the DB service that provides OLAP?
Red shift
What is the cost of RDS backups?
nothing. stored in S3
Characteristics of RDS snapshots?
Manual
retained after RDS instance is deleted
When an RDS instance is restored will the end point be the same
No
In RDS multi-az you lose the primary. What happens
Endpoint auto fails over by re-pointing the DNS alias to a healthy copy.
What DBs provide multi-az?
MySQL
Postgres
MariaDB
Aurora
What DBs provide read replicas??
Aurora
MySQL
What are the two types of redshift configurations?
single node
multi node
What are the max number of compute nodes in a redshift multi node config?
128
Describe red shift security characteristics?
To keep data secure in transit, Amazon Redshift supports SSL-enabled connections between your client application and your Redshift data warehouse cluster.
To keep your data secure at rest, Amazon Redshift encrypts each block using hardware-accelerated AES-256 as it is written to disk. The blocks are backed up as is, which means that backups are encrypted as well.
By default, Amazon Redshift takes care of key management but you can choose to manage your keys using your own hardware security modules (HSMs) or manage your keys through AWS Key Management Service.
What are the max number of aurora replicas?
15
Aurora scaling characteristics?
10 GB to 64TB up to 32 vCPUs and 244 GB or mem
2 copies of DB in each AZ w/ min of 3 AZs
Transparently handle loss of up to two copies
Self healing
Max # of read-replicas on their DBs?
Aurora Replicas 15
MySQL replicas 5
