Deep Dive into EC2Hiroshi Wada

Jul 24, 2013NICTA Software Dev Tools Series #10

Many many building blocks ...

AWS resources/services are relatively low level

Pick right resources and build your app

Steep learning curveSimilar services with different natureNon-obvious restrictionsDependency among services/resources

Easy to understand them by going *behind* the API

Region andAvailability Zone

Region: location where a set of services are providedRegions are completely isolated from each otherDifferent API endpoints, no replication across, ...Regions may provide different services

Availability Zone: a collection of data centersA region has ~4 AZsIsolated to prevent outage from spreadingResources may or may not be replicated

aws.amazon.com/about-aws/globalinfrastructure/

Region-bound and AZ-bound resources

Resources bound to an accountDNS, Access Management, ...

Resources bound to a RegionS3, machine images, DynamoDB, Elastic IP, LB, ...Replicated across AZs - highly available/durable

Resources bound to an AZInstance (VM), EBS (disk volume), ...Building fault tolerance is your job

Architecture in AZ (guess!)

RegionAZ-"a"

Rack serversoperating VMs(IP network)

No persistent diskfor users

(only ephemeral disks)

Storage AreaNetwork

provisioningEBS

(redundancy, RAID, ...)

FibreChannel

Internet

Rack serversoperating resources shared among AZs

(S3, LB, etc)

Communicationand replicationacross AZs(internal IP network)

Internet

AZ-"b"

Architecture in AZ (guess!)

RegionAZ-"a"

Rack serversoperating VMs(IP network)

No persistent diskfor users

(only ephemeral disks)

Storage AreaNetwork

provisioningEBS

(redundancy, RAID, ...)

FibreChannel

Internet

Rack serversoperating resources shared among AZs

(S3, LB, etc)

Communicationand replicationacross AZs(internal IP network)

Internet

AZ-"b"

Architecture in AZ (guess!)

RegionAZ-"a"

Rack serversoperating VMs(IP network)

No persistent diskfor users

(only ephemeral disks)

Storage AreaNetwork

provisioningEBS

(redundancy, RAID, ...)

FibreChannel

Internet

Rack serversoperating resources shared among AZs

(S3, LB, etc)

Communicationand replicationacross AZs(internal IP network)

Internet

AZ-"b"

Architecture in AZ (guess!)

RegionAZ-"a"

Rack serversoperating VMs(IP network)

No persistent diskfor users

(only ephemeral disks)

Storage AreaNetwork

provisioningEBS

(redundancy, RAID, ...)

FibreChannel

Internet

Rack serversoperating resources shared among AZs

(S3, LB, etc)

Communicationand replicationacross AZs(internal IP network)

Internet

AZ-"b"

Two types of instances: EBS backed

Root disk is in SAN and directly attached to machineStop/restart to change underlying machine in an AZ

Life cycle: start <-> stop -> terminateCharge for the use of EBS (capacity and I/O)

attach directly

EBS volume(virtual disk)

SAN

VM

servers and hypervisors

Two types of instances:instance store

Root disk is loaded from S3 to an ephemeral diskNo persistent storage (only ephemeral)

Life cycle: start -> terminateCustomization

Re-create image or use cloud-init on boot

Image

S3 load into ephemeral disk

VM

servers and hypervisors

Lifecycle of disks/images

A machine image is stored in S3=> you can launch instances in any AZ in the region

An instance is running on a physical machine=> bound to an AZ. Not highly available.

Image

S3

replicated among AZs(not visible to users)

load into an EBS volume

attach directly

EBS volume(virtual disk)

SANload intoephemeral disk

VM

AZ

Lifecycle of disks/images

An EBS volume is in SANs=> bound to an AZ

Only attachable to an instance in same AZNot durable compared to S3

Image

S3

replicated among AZs(not visible to users)

load into an EBS volume

attach directly

EBS volume(virtual disk)

SANload intoephemeral disk

VM

AZ

Lifecycle of disks/images

Snapshot (or machine image) of an EBS volume=> stored in S3. Bound to region. High durability

Creating instance-store images is not trivial ...

Snapshot,image

S3

EBS volume(virtual disk)

SAN

AZ

Create an image from VMEBS VM

Take a snapshot of a volume

Storage options - two flavors

"Regular" diskPros: you're familiar with it. random access.Cons: less available/durable (AZ bound)Services: EBS, ephemeral disks, RDS, ...

Key-value, NoSQLPros: high durability via distributionCons: proprietary interfaceServices: S3, Dynamo DB, SQS, ...