EBS Flashcards
What is HA of an EBS Volume?
EBS automatically replicated within an AZ
What is the scalability of EBS?
You can change types or increase capacity with no downtime and no performance impact
What is the use case for gp2 and gp3?
Boot volume, test and development, no latency sensitive requirement. Installing an OS
What is the IOPS max for gp2? gp3?
16000 iops
What is the use case for io1/io2?
Need high performance, latency sensitive, database workloads, OLTP, expensive, greater than 16k iops needed
What is the iops for io1/io2?
64000 iops per volume
What is the use case for st1?
low cost to store lots data, frequently accessed, throughput intensive, for big data, etl, data warehouse, log processing?
What should you think when you hear big data, etl, data warehouse, log processing?
Throughput, not iops
What restriction does st1 have?
It can’t be a boot volume?
What is the use case for sc1?
Need lowest cost option, infrequently scanned data, performance not a factor
What restriction does sc1 have?
Can’t be a boot volume
Where is the EBS volume location in realtion to the EC2 instance?
It is in the same AZ
How do you share a snapshot?
Snapshots can be shared in the same region but outside region need to create a copy of the snapshot in that region.
How do you take a consistent snapshot?
You stop the ec2 instance first
How would you move an ebs volume to a different region?
Take a snapshot of the ebs volume. Copy snapshot to another region. You can encrypt snapshot if it is unencrypted.
How would you move an ec2 instance to a different region? **
Take snapshot of ebs, copy snapshot to other region, create an ami of the snapshot and launch.
How would you encrypt an unencrypted ebs volume?
Copy the snapshot of the unencrypted ebs volume, and then launch an new instance using an ami of the new snapshot
What happens to encryption if you take a snapshot of an encrypted volume?
The snapshot will be encrypted and all volumes made from the snapshot are encrypted
What does end to end encryption mean for an ebs volume?
Snaphots are encrypted. data is encrypted at rest and in flight between instance and volume
What happens by default to the root volume if an instance is terminated?
The root volume is terminated
What is ec2 hibernation? On Hibernation? On Startup?
Instance has contents of RAM saved to disk. On startup processes are resumed, RAM is reloaded from disk, instance retains its instance id, prev attached volumes are reattached.
Does EC2 hibernation instances keep their instance id?
Yes they keep their instance id
Why use EC2 hibernation?
Makes booting up your instance faster
What is the size restrictions for RAM in EC2 Hibernation? How long can hibernation be?
150 GB RAM max and 60 days
What is EFS?
Elastic File System is a NFS for EC2
How many EC2 instances can use EFS? Are there AZ restrictions?
Multiple EC2 instances can use the same EFS, and instances can be in different AZ’s (unlike EBS)
What OS works with EFS?
Only Linux
Why use EFS?
Multiple instances that need access to a central NFS. Automatic scaling of capacity, highly scalable to petabytes, pay for what you need
What are the 2 performance types for EFS?
- General Purpose (web servers, CMS)
2. Max I/O (media processing, big data)
Does EFS have lifecycle management?
Yes
What are the storage tiers for EFS?
Frequently accessed and Infrequently accessed
How many concurrent NFS connections does EFS support?
Supports thousand of connections
What is the consistency of reads for EFS? What is the HA?
Read after write consistency. Multi AZ
What is FSX for Windows?
Managed native Windows File System storage on Windows Server
When should you use FSX over EFS?
When you need Sharepoint or AD migrations.
What is the difference between FSX and EFS? Protocols?
FSX is for Windows using SMB. EFS is for Unix.
What is SMB?
Server Message Block - protocol for windows FS
What is FSX for Lustre?
Linux Managed Filesystem for compute intensive workloads
What use cases are there for FSX for Lustre?
HPC, Machine Learning, AI, massive dataset processing, media processing
Where does FSX for Lustre store things?
Stores things in S3
What is an AMI?
Amazon machine image contains the info needed to launch an instance. Blueprint for an instance
What is the difference between instance store vs ebs store?
Root volume is backed by an ebs volume from an ebs snapshot. Root volume is backed by a template stored in S3
What happens if you stop an instance store? What hap-pens if the instance hardware fails?
You can’t stop an instance store. You will lose all data if the instance hardware fails
What happens if you reboot an instance store?
Data will be retained
What happens if you terminate and instance with instance store?
Data is lost
What happens if you stop an ebs store? reboot ebs backed instance?
Data is retained in both cases
What happens if you terminate and instance with ebs store?
The default is to terminate the root volume, but can be changed to retain
What is AWS Backup?
Allows consolidated backup across AWS services.
What is AWS Backup with Organizations?
Allows backup of multiple AWS accounts in your organization. Centralized control of backups of multiple services in multiple accounts
Why use AWS Backup?
Centralized control, can set lifecycle policies, automate backups, enforce backup policies like encryption
What engines does RDS support?
Postgresql, Mysql, Oracle, MariaDB, Aurora, Sql Server
What is OLTP vs OLAP? What should RDS be used for?
OLTP = large amounts of small transactions
OLAP = large amounts of data, analysis and complex queries
RDS is for OLTP
How does Multi AZ work for RDS? Is the copy async or sync?
There is a primary instance, and a standby instance in another AZ. If primary fails, then AWS switches DNS to point to standby. Data is synchronously copied to standby.
Is Multi AZ used for performance gains in RDS?
No, Multi AZ is only for DR
What are Read Replicas used for?
Increasing performance of RDS
What is a read replica?
A read only copy of the db
Where can you deploy a read replica?
Can put a read replica in a different AZ or different Region
What DNS endpoint does Multi Az use vs read replica?
Multi AZ uses the same DNS endpoint while a read replica has a separate DNS endpoint
How many read replicas can you have for RDS?
5 per database for MySQL,MariaDB,Postrgresql,Oracle, Sql Server
For Aurora you can have 15 replicas
Can you promote a read replica into a standalone db?
Yes you can, but it breaks replication
What must be turned on in RDS to enable Read Replicas?
Automatic Backups
Can you make a Read Replica Multi AZ?
Yes you can make read replicas multi az
Can you access the stand by RDS Instance in Multi AZ?
No you cannot access this instance while the primary db is still running
What is Aurora?
Amazon proprietary use of postresql/mysql bringing commercial support/reliability with open source cost/simplicty
What performance increases can you get with Aurora?
You can get 5x performance increase
How many copies are kept for Aurora?
2 copies in each AZ for a total of 6 copies
How many read replicas can Aurora have? vs. non-Aurora?
15 read replicas vs 5 read replicas
Can you share EBS snapshots with other accounts? What needs to be done for you to do so?
Yes you can. To share EBS snapshots publicly, the snapshot must be unencrypted. For encrypted snapshots you must share the customer managed KMS key as well
Why use Aurora?
Storage and CPU Autoscales up and down - perfect for unpredictable workloads
What is Aurora Serverless?
Aurora Serverless is pay for what you use, on demand and auto scales up or down
How many copies of data loss can happen for write? for read?
2 copies can be lost for write, and 3 for read
How does failover for Aurora work? vs. non-Aurora?
There is automated failover to a read replica in Aurora while non-Aurora does not have failover
How does backups work?
Automated backups are on by default and continuous
What is DynamoDB?
A NoSQL document/key-value database for millisecond latency.
What are 4 facts about DynamoDB?
- It is on SSD
- Spread across 3 geographic distinct datacenters
- Default is eventually consistent reads
- Can be strongly consistent reads
What is DAX?
DynamoDB Accelerator which is a pass through cache, apps will talk to DynamoDB and it will handle the caching
What is the general point of ACID?
Your transaction all succeeds or none at all
How do you use ACID in DynamoDB?
Use DynamoDB Transactions for acid on 1 or more table in a single region and account
What region do DynamoDB backups live in?
The same region as the DynmoDB table
What is the retention for On-Demand Dynamo backups?
Retained until deleted
What is the retention for Dynamo Point in Time Recovery?
35 days and at 5 minutes in the past interval
Is Dynamo PITR turned on by default?
No it is not turned on by default
What is DynamoDB Streams?
Time ordered sequences of changes to items in a table
How long does data stay in a DynamoDB Stream?
24 hours
What components are in a DynamoDB stream?
The stream, stream records aka sequences, shards aka a grouping of sequences
What must be done to use DynamoDB Global Tables?**
You need to turn on DynamoDB Streams
Why use Dynamo Global Tables?
- Provides multi region, multi master replication for HA and DR
- No need to rewrite applications
- Your application can be globally located
- Less than 1 second latency
Why use DAX?
10x performance increase, changes latency from milliseconds to microseconds, fully managed caching
