Amazon Web Services: Simple Notification Service

In this blog, we will discuss Simple notification service

SNS sends notices to internal assets from AWS:from Application to user OR to application or user. SNS is useful for monitoring, alerts and logging.

SNS Setup

To set up a SNS,

•  Create a Topic. Think it as a mailbox or email alias
• Add Subscribers: Think of it like a  multiple recipients.If more than just email
• Subscribers must confirm since this is an internal message
• And you send messages to the Topic. All confirmed subscribers immedialy et the message

SNS Overview

• it obviates the need to build custom messaging
• its push based messaging
• Deep integration with other AWS services
• it has API and AWS console support

.Next we identify SNS subscriber types

• Http/s
• email/ email-JSON
• SMS
• SQS

SNS Service integration

• Autoscaling: Publish instance add/remove messages
• EC2:Application on EC2 can leverage SNS
• S3
• Cloudwatch

Amazon Web Services: Virtual Private Cloud Advanced

In the last blog we  covered VPC. In this blog we will cover advance VPC
In this blog primarily the  focus will be on

• Isolation internal tiers/Customers from each other
• Programatically connecting/disconnecting Internet gateway

Isolation internal tiers/Customers from each other

Please look at teh diagram below: There is a web/App tier and compute Tier Both are in AZ-A and AZ-B. Both have different VPC and Routing table

So this way you can isolate different tiers and customers from each other

Programatically connecting/disconnecting Internet gateway

Amazon Web Services: Virtual Private Cloud

In this blog, we will discuss Amazon Web Services,Virtual Private Cloud (VPC)

 Please have a look at the diagram below:

Customer 1 (C1), Customer 2(C2) and Customer 3 (C3) have their EC2 instances. Without VPC, C2 can ping and try to access easily C3 s EC2 instances.

VPC Benefits:

• Logical isolation of your resources from other customers, from internal divisions and application tiers.
• Control Over:

          --Address Spaces

          --Subnets: Do you know minimum size of subnets should be /28 or 14 ip addresses and maximum size should be eual to size of VPC. We can have 200 Subnest per AZ

          --Route Tables and NATs

          --Network Gateway (VPN and Internet)

          --Ingress and egress security groups

          --Multiple Elastic Network Interface (ENI) on VPC EC2

          --Control over dedicated hardware

VPC Limitations are:

• Only Select resources like ELB( w/support to balance web/app tier), EC2( and EBS, Autoscaling), RDS, Elasticache can be launched in a VPC
• You will want to launch all of them together either inside or outside VPC
• No multicast or broadcast support
• 5 VPCs per account per Region
• 200 subnets per VPC
• 5 vpc eip per account per region
• 1 internet gateway per VPC
• No. Of ENIs per instance depend upon type of instance

VPC Setup:

• Create VPC: Choose reaonable IPs
• Creeate Subnets
• Create route tables, NACLs
• Launch assets into VPC
• Create IG.VPG

So this is the basic understanding of VPC

Amazon Web Services: ElastiCache

In This blog we will discuss Elastic Cache

ElastiCache is the in memory caching mechanism. It is the memcache under the hood. It is 100% API compliant.More appropriately it is a memcache cluster


Memcache is a popular , opensource in -memory cache. it is  very fast read and writes.It takes burden of backend resources

Memcache is a key value store.It is a NOSql DB. Its only access method is a key

ElastiCache is actually a memcache cluster. it is a distributed collection of cache nodes

Its available in only Single AZ

Cache nodes are very user specified types

• very much like EC2 Instance type
• can be wrapped with security groups
• can buy capacity reservations
• Resizeable ( remove or add nodes)

To Setup and ElastiCache

• Choose an AZ
• Chose node types, # of nodes
• Launch Cluster
• Connect application by pointing to elasticache endpoint
• Benchmark, resize ( if necessary)

Elasticache Expiry

• Expiring Key is controlled via the elasticache API (memcache commands)
• Scheduled
• on demand

ElastiCache Pricing

• It has per hour node charge
• Bandwidth Charges- Bandwidth Charges are free inside the AZ but Charged $0.1/GB in or out of AZs

Amazon Web Services : CloudFront

In this blog we will discuss amazon cloudfront. What is cloudfront?

Cloudfront is a CDN or content delivery network. It utilizes Edge Locations near to user. Since its a CDN we need to remember content needs and origin and it can be expire also.

CDN are popular static websites.Using CDN, you can either make

• Download distributions like products, documents and data
• or Streaming distribution like audio or video

Cloudfront has native integrations to AWS (S3 origins).It is very cost effective

To setup a cloudfront, one must create a distribution

• Must define Http or steaming
• Must Specify an origin: Any web accessible server will work ( EC2, S3, Private server)\
• Can also specify TTL, logging, Path matches
• Distribution domain created for you for example like d1234.cloudfront.net or can also easily create vanity URLS

Use Distribution domain in links

When user access the CDN URL, Cloudfront directs them to their closest Edge. Everyone loads content faster.

Cloudfront is a pull mechanism.Each edge pulls from origin if it doesnt have the requested content

       

Each Pull is charged

• from origin
• from each user

Invalidation request are charged.

But you can get Reservation capacity discount if you know your load in future and you reserve in advance.

Amazon Web Services: Storage

In this blog we focus on Storage. We will discuss many storage options available in AWS.

So we will look at S3 Storage, RDS( Managed MySQL, Oracle and SQL) and DyanamoDB( NOSQL database)

Lets start with S3 Storage.

S3 Storage ( Simple Storage Service) is an object storageand is best used for static assests. It is the cheapest option to store and serve data. There is no limits on the number of the objects that you can create. It is extremely durable.

S3 is extremely scalable too. All objects are natively web accessible.It can also host static websites.

There are certain S3 limitations:

• Latency
• Its a WORM ( Write Once Read Many) Storage.
• It cannot serve Dynamic content
• Its 100buckets and 5TB Max sizeon the objects
• bare bones (write, read, delete)

RDS ( Relation Database service) is a hands off RDBMS (MySQL, Oracle and SQL). RDS is manually scalable like EC2. RDS has HA already baked in ( multi-AZ master/slave). RDS also has DR baked in with automated backups and real time snapshots. It is very cost effective. It is also very scalable.

RDS has some limitations too. It has upward vertical limitation. RDS has 3TB max db size.It has only SQL Interface with No SSH or hardware access.


DyanamoDB deals awesomely with 3Vs of big Data( variety, velocity and volume). It has HA baked in. It is highly scalable and cheap. It has drop dead administration

Amazon Web Services: Cloudformation

In this blog, we will discuss Cloudformation.
cloudformation helps in codifying creation of stack of resources.

What are stack of resources? A stack could be:

• ELB
• Auto scaling group
• EC2
• RDS (Database)
• All connections between them

There are many benefits of cloudformation, namely:

1. Your infrastructure as a code
2. can be version controlled
3. Modularization ( templates can contain other templates)
4. Enforce one way to deploy
5. Cost nothing

Signing up with Cloudformation means signing up with AWS services that Cloudformation can create

With Cloudformation you can setup billing alarms. To learn how to setup billing alarms go to

https://portal.aws.amazon.com/gp/aws/developer/account?ie=UTF8&action=billing-alerts 

There are 200-300 pre-packaged amazon templates available. The templates are JSON based. The templates can accespt run-time parameter [Instance type (small for test), Kep pair (prod vs Test)]

Templates can also update running stack

Templates have 7 section

• version
• description
• parameters
• mapping
• resources
• properties
• output

The link for templates is

http://aws.amazon.com/cloudformation/aws-cloudformation-templates/