Databases Flashcards
How to implement synchronous data replication for the RDS database to help meet the RTO?
When creating a database enable Multi-AZ
How to implement asynchronous data replication for the RDS database?
Create Read Replica
AWS Database that can run complex analytic queries against terabytes of structured data, using sophisticated query optimization, columnar storage on high-performance storage, and massively parallel query execution
Redshift
How long will a failover of an RDS database typically complete if Multi-AZ is enabled?
1-2 minutes
Database type that is great for transactional data
Relational Database
How to setup Automatic Failover in RDS
Turn on MultiAZ
Can you change the instance size of RDS
Yes, but you may have downtime
Automated Backups Default for RDS
7 days
Automated Backup range for RDS
0 - 35 days
Aurora compatible Databases
MySQL PostgresQL
Max Read Replicas with Arurora
15
Aurora Serverless compatible Databases
MySQL
ACID compliant Document Databases
DynamoDB
DynamoDB Consistency
Eventually Consistently by default
Strong Consistent Available
Request Throughput of DynamoDB
1 RCU 1 item 4 KB/sec
1 WCU 1 item 1 KB/sec
Does DynamoDB scale automatically
Yes
You can also schedule automatically and set a max and min throughput
DynamoDB Streams are kept for up to what length of time
24 hrs
How to help a read heavy DynamoDB table to reduce latency of reads
Enable DAX caching
If you have customers in multiple regions, and app uses DynamoDB how to make it so customers are not impacted by latency
DynamoDB global tables
Consistency of DynamoDB Global Tables
Eventually Consistency ONLY across regions, for Strong consistent have to be in same region
How to expire items in DynamoDB
Set a TTL
If you turn on PITR in DynamoDB how long does this data go back?
35 days
What services can you use to migrate data to DynamoDB?
AWS Data Pipeline
AWS Glue
AWS EMR Hive (DynamoDB connector)
AWS DMS (cassandra or Mongo to Dynamo)
How many local secondary indexes can you have with a DynamoDB table?
5
Local Secondary Index Consistency Support
Strong and Eventually consistent reads
Describe Local Secondary Index
Created on Table Creation
Same partition Key
Different Sort Key
Describe Global Secondary Index
Partition can span all keys (does not need to be unique) and any sort key
Can be created at any time
Max number of Global Secondary Indexes
20
Global Secondary Index Consistency Support
Eventually Consistent ONLY
Size limit of items in DynamoDB
400 KB
Recommended item size in DynamoDB
1-4KB
DynamoDB how to ensure that item has not changed since you read it?
Use optimistic locking w/ version #
2 Flavors of Elasticache
Memcached
Redis
Can Elasticache be used on prem?
Yes, 2 options
VPN or Direct Connect
Describe MemcacheD
easier, simpler data, static data
Describe Redis
more complex and ever changing data. Use if need HIPPA compliant
Caching Strategies for DynamoDB
Lazy Loading - write to cache when data requested
Write Through - proactive caching on write to DB
Use case of Elasticache
Real Time Leaderboards
Service used to migrate databases to AWS
Amazon DMS
If heterogenous transitions how to translate schema before DMS.
Use Amazon Conversion Schema Tool (SCT)
Redis-compatible, durable, in-memory database service that delivers ultra-fast performance.
MemoryDB for Redis
Mongo Compatible Database
DocumentDB
Wide Column Database compatible with Apache Cassandra
Amazon Keyspaces
Graph Database
Neptune
Serverless time series database service for Internet of Things (IoT) and operational application
Amazon Timestreams
Ledger database. Immutable records.
QLDB
Petabyte scale, fully managed data warehousing service.
Redshift
What types of Data/file formats can Amazon Redshift Spectrum Query in S3
Avro, CSV, JSON, ORC, and Parquet
Language that you can use to query Redshift
SQL (Postgre)
How to migrate to Redshift
Workload Qualification Framework (WQF) which uses AWS Schema Conversion Tool
For an Aurora Database how to direct the write operations of the production traffic to your high-capacity instances and point the reporting queries sent by your internal staff to the low-capacity instances.
Create a custom endpoint in Aurora based on the specified criteria for the production traffic and another custom endpoint to handle the reporting queries
How to automatically backup a DynamoDB table to another region or account
AWS Backup
How to automatically backup a DynamoDB table in the same region and account
Enable DynamoDB PITR
What are the events that will make Amazon RDS automatically perform a failover to the standby replica?
Loss of availability in primary Availability Zone.
Loss of network connectivity to primary.
Compute unit failure on primary.
Storage failure on primary.
What should you do if your RDS instance is running out of disk space?
Enable Storage Autoscaling (you can set a max threshold)
Max backup retention for RDS database?
35 days
RDS can you connect to standby instance if MULTI-AZ is turned on?
FALSE, only primary