RDS, Aurora & ElastiCache Flashcards

1
Q

What is RDS?

A

Relational database service

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2
Q

What dies RDS manged?

A
  • Automated provisioning, OS patching
  • Continuous backups and restore to specific timestamp (Point in Time Restore)!
  • Monitoring dashboards
  • Read replicas for improved read performance
  • Multi AZ setup for DR (Disaster Recovery)
  • Maintenance windows for upgrades
  • Scaling capability (vertical and horizontal)
  • Storage backed by EBS (gp2 or io1)
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3
Q

What you can’t do on RDS?

A

You cannot SSH into your instance

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4
Q

Which backups does RDS have?

A

Full daily backup

Logs - every 5 min.

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5
Q

How long are the backups kept? Which point in time can you go back to?

A

Ability to restore to any point in time (from 5 minutes ago or seven days ago)

7 days retention - can increase to 35

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6
Q

What features do DB snapshots have?

A

Manually triggered

Kept of as long as you want

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7
Q

What features do RDS storage auto scaling have?

A

Helps increase storage dynamically

increase automatically when DB run out of free space - avoid manually scaling

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8
Q

What are the conditions for RDS to start auto scaling?

A
  • Free storage is less than 10% of allocated storage
  • Low-storage lasts at least 5 min
  • 6 hours have passed since last modification
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9
Q

What kinds of applications can benefit from RDS auto scaling?

A

Useful for applications with unpredictable workloads

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10
Q

What are the features of RDS read replicas for read scalability?

A
  1. Up to 5 read replicas: (1)Within AZ (2)Cross AZ (3) Cross region.
  2. ASYNC - reads are eventually consistent.
  3. Promoted to their won DB.
  4. Must update the connection string to leverage read replicas
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11
Q

How do the network costs for RDS read replications in various AZs and the same region differ?

A

For RDS read replicas within the same region - you don’t need to pay that fee.

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12
Q

What are the benefits of RDS Multi AZ?

A
  • SYNC replication
  • One DNS name – automatic app failover to standby.
  • Increase availability
  • Failover in case of loss of AZ, loss of network, instance or storage failure.
  • No manual intervention in apps.
  • Not used for scaling
  • Multi-AZ replication is free.
  • Note:The Read Replicas be setup as Multi AZ for Disaster Recovery (DR)
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13
Q

Can the Read Replicas be setup as Multi AZ for Disaster Recovery (DR)?

A

Yes!

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14
Q

Hod do we make a RDS goes from single AZ to multi AZ?

A
  1. Click “modify” for the database.
  2. Zero downtime operation (no need to stop the DB)
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15
Q

What append internally when you go from single AZ to multi AZ?

A
  • A snapshot is taken
  • A new DB is restored from the snapshot in a new AZ
  • Synchronization is established between the two databases
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16
Q

RDS security - What is “at rest encryption” features?

A
  • Possibility to encrypt the master & read replicas with AWS KMS - AES-256 encryption
  • Encryption has to be defined at launch time
  • Master must be encrypted if not cannot be encrypted
  • Transparent Data Encryption (TDE) available for Oracle and SQL Server
17
Q

RDS security - What is “in flight encryption” features?

A
  • SSL certificates to encrypt data to RDS in flight.
  • Provide SSL options with trust certificate when connecting to database.
18
Q

How to encrypt RDS backups?

A
  • Snapshots of un-encrypted RDS databases are un-encrypted.
  • Snapshots of encrypted RDS databases are encrypted.

Can copy a snapshot into an encrypted one.

19
Q

How to encrypt un-encrypted RDS database?

A
  • Create a snapshot of the un-encrypted database
  • Copy the snapshot and enable encryption for the snapshot
  • Restore the database from the encrypted snapshot
  • Migrate applications to the new database, and delete the old database
20
Q

What are the RDS network security two features?

A
  1. RDS databases are usually deployed within a private subnet, not in a public one.
  2. RDS security works by leveraging security groups (the same concept as for EC2 instances) – it controls which IP / security group can communicate with RDS
21
Q

What are the RDS IAM features?

A
  1. IAM policies help control who can manage AWS RDS (through the RDS API).
  2. Traditional Username and Password can be used to login into the database or authentication token obtained through IAM & RDS API calls (lifetime of 15 minutes)
  3. IAM-based authentication can be used to login into RDS MySQL & PostgreSQL - Only!!
22
Q

What are the benefits of IAM authentication?

A
  1. Network in/out must be encrypted using SSL.
  2. IAM to centrally manage users instead of DB.
  3. Can leverage IAM Roles and EC2 Instance profiles for easy integration
23
Q

What is yours responsibility at RDS security?

A
  1. Check the ports / IP / security group inbound rules in DB’s SG
  2. In-database user creation and permissions or manage through IAM
  3. Creating a database with or without public access
  4. Ensure parameter groups or DB is configured to only allow SSL connections
24
Q

What is amazon Aurora?

A
  • Aurora is a proprietary technology from AWS (not open sourced)
  • Aurora support Postgres and MySQL
  • “AWS cloud optimized” and claims 5x performance improvement over MySQL on RDS, over 3x the performance of Postgres on RDS.
  • storage automatically grows in increments of 10GB, up to 128 TB.
  • can have 15 replicas, the replication process is faster (sub 10 ms replica lag).
  • Failover in Aurora is instantaneous - High available native
  • Cost 20%more then RDS.
25
Q

What makes Aurora High Availability and Read Scaling

A
  • 6 copies of your data across 3 AZ:
    • 4 copies out of 6 needed for writes
    • 3 copies out of 6 need for reads
    Self healing with peer-to-peer replication
    • Storage is striped across 100s of volumes
  • The master Instance takes writes
  • Automated failover for master in less than 30 seconds.
  • Master + up to 15 Aurora Read Replicas serve reads.
  • Support for Cross Region Replication
26
Q

What are Aurora features?

A
  • Automatic fail-over
  • Backup and Recovery
  • Isolation and security
  • Industry compliance
  • Push-button scaling
  • Automated Patching with Zero Downtime
  • Advanced Monitoring
  • Routine Maintenance
  • Backtrack: restore data at any point of time without using backups
27
Q

What are Aurora security features?

A
  • Similar to RDS because uses the same engines
  • Encryption at rest using KMS
  • Automated backups, snapshots and replicas are also encrypted
  • Encryption in flight using SSL (same process as MySQL or Postgres)
  • Possibility to authenticate using IAM token (same method as RDS)
  • You are responsible for protecting the instance with security groups
  • You can’t SSH
28
Q

What is Aurora custom endpoints?

A
# **Define a subset of Aurora Instances as a Custom Endpoint**
• Example: **Run analytical** queries on **specific replicas**
• The Reader Endpoint is generally not used after defining Custom Endpoints
29
Q

What is Aurora serverless? What are the benefits?

A

Automated database instantiation and auto- scaling based on actual usage

  • Good for infrequent, intermittent or unpredictable workloads
  • No capacity planning needed
  • Pay per second, can be more cost-effective
30
Q

How do I obtain immediate Aurora failover?

A

by creating multi-master node - multiple DB connections

every node does R/W

31
Q

What is “Global Aurora”?

A
  • Aurora Cross Region Read Replicas:
    • Useful for disaster recovery
    • Simple to put in place
  • Aurora Global Database (recommended):
    1 Primary Region (read / write)
    • Up to 5 secondary (read-only) regions, replication lag is less than 1 second
    • Up to 16 Read Replicas per secondary region
    • Helps for decreasing latency
    • Promoting another region (for disaster recovery) has an RTO of < 1 minute
32
Q

What is Aurora machine learning?

A
  • Enables you to add ML-based predictions to your applications via SQL
  • Simple, optimized, and secure integration between Aurora and AWS ML services
  • You don’t need to have ML experience
33
Q

Which services are Aurora ML support?

A
  • Amazon SageMaker (use with any ML model)
  • Amazon Comprehend (for sentiment analysis)
34
Q

Use cases for Aurora ML?

A
  1. fraud detection
  2. ads targeting
  3. sentiment analysis
  4. product recommendations
35
Q

What is Amazon ElasticeCache?

A
  • ElastiCache is to get managed Redis or Memcached
  • Caches are in-memory databases with really high performance, low latency
36
Q

What is Amazon ElasticeCache use for?

A
  • Helps reduce load off of databases for read intensive workloads
  • Helps make your application stateless
  • AWS takes care of OS maintenance / patching, optimizations, setup, configuration, monitoring, failure recovery and backups
37
Q

What does Using ElastiCache involves?

A

Using ElastiCache involves heavy application code changes

38
Q

What the ElastiCache don’t support?

A

Do not support IAM authentication