EC2 Fundamentals Flashcards
What is IAM Access?
Allows IAM users and roles to access billing and cost management console.
How to set up billing alerts?
Budgets
are you billed for a stopped state instance
no
if you stop and start an instance do you have the same IP
no to public, yes to private
What is a security group
They control what traffic is allowed in and out of instances
security groups have allow or deny rules
allow
by default all inbound traffic is
blocked
by default all outbound traffic is
allowed
port 22, 21, 80, 443, 3389
SSH linux & SFTP, FTP, HTTP, HTTPS, SSH windows
when you see a timeout what does this mean?
security group issue
You can only cancel spot instant requests in which states
open, disabled, active
to terminate a spot instance you need to
cancel and then terminate
what are the ec2 placement groups
spread, cluster, partition
what is cluster
clusters instances in a low latency group within an AZ
what is spread
spreads instances across underlying hardware - max 7 per group per AZ - critical applications
what is partition
spreads instances across many different partitions in an AZ - scales 100s of ec2 in a group
pros and cons of cluster
pro - great network (low latency)
con - if rack fails then instances fails
use case of cluster
big data jobs which are quick
applications that need low latency and high network throughput
pros and cons of spread
pros - spread across az, if one fails they all dont fail
cons- limited to 7 instances per group per az
use case of spread
apps that need high availability
apps that need fault tolerance
ENI
virtual network card
ENI are az specific
yes
can eni be created independently and attached to an instance
yes
what is ec2 hibernate
it is where the os is in hibernation and the ram is stored in the root ebs volume, once the instance is running again the ram will be moved back to the instance
use cases for hibernation
long running instance
saving the ram state
want a quick boot time cause services take long to initialise
what is an ebs volume
network drive attached to instances. allows you to persist data even after instance is terminated
ebs volumes are az specific
yes
by default, root ebs volumes are…
deleted on termination
by default, attached ebs volumes are..
not deleted on termination
can you have more than one ebs attached to an instance
yes
whats a snapshot
a backup of ebs volume at any point of time
do you need to detach volume to do a snapshot
no, but it is recommended
can you copy snapshots across region or az
yes
can you archive the snapshot
yes, 75% cheaper. it takes 24hrs to 72hrs to retrieve it from archive
recycle bin for snapshots
yes, from 1 day to 1 year, recover accidental deleted snapshots
what is AMI
customises your instance - configuration, os, monitoring, software
AMI are region specific?
yes, but can be copied across regions
whats is an EC2 instance store
a hard drive attached to instance with higher performance than ebs volumes
pros and cons of instance store
pros - high throughput i/o
cons - ephemeral storage - not for long term storage
use case of instance store
cache buffer scratch data temporary content
which ebs volume can attach to many instances in same az
io1 io2 family
how many instances for multi-attach ebs
16
what is EFS
network file system that can be mounted on many instances across az
