Sunday, 17 December 2017

AWS – Concepts and Components

AWS – Concepts and Components
  • AWS Global Infrastructure
    • 12 Regions & 33 AZs, 5 more Regions & 11 more AZs coming throughout the next year
    • Region = 2 or more AZs
    • AZ = DataCenter
    • Edge Location = CDN End Points for CloudFront
  • Networking
    • VPC = Virtual Private Cloud
    • Direct Connect = connecting to AWS w/out using Internet connection
    • Route53 = DNS service (port 53… duh)
  • Compute
    • EC2 = virtual server
    • EC2 Container Service = EC2 with Docker
    • Elastic Beanstalk = Service for deploying web applications and services. “AWS for beginners”
    • Lambda = “Most powerful/revolutionary service”. Run code w/out servers. Pay for execution time, only charged when code is executed.
  • Storage
    • S3 = Object based storage, a place to store flat files in the cloud
    • CloudFront = CDN (content delivery network), local caching of content
    • Glacier = long term backup, 3-5 hours to retrieve data
    • EFS = NAS in the cloud, block level storage (in preview)
    • Snowball = Import/Export service. For moving large amounts of data in/out of AWS. They ship you a physical suitcase of disks J
    • Storage Gateway = VM that you run locally that replicates data from local datacenter to AWS
  • Databases
    • RDS = SQL, Aurora, Oracle, PostgreSQL, MySQL, MariaDB
    • DynamoDB = NoSQL
    • Elasticache = Caching DB services in cloud to relieve stress on RDS for high I/O environments
    • Redshift = Data warehousing service. Great performance
    • DMS = Database Migration Services. How to migrate/convert local DBs into AWS
  • Analytics
    • EMR = Elastic Map Reduce. A way of processing big data
      • Managed web service Hadoop clusters
    • Data Pipeline = moving data from one service to another
    • Elastic Search = Managed service to deploy/operate a search engine in cloud
    • Kinesis = managed service platform for real time streaming of big data.
      • Web apps, mobile devices, wearables generate huge amounts of streaming data.
      • Use kinesis to digest big data
    • Machine Learning = for use by developers to work with machine learning…. (not in test)
    • Quick Sight = Business Intelligence service (not in test)
  • Security & Identity
    • IAM = control users, roles, groups, policies
    • Directory Services
    • Inspector = install agents on EC2 instances & check for vulnerabilities (not in test)
    • WAF = Web Application Firewall condition sets:
      • IP Match
      • String Match
      • SQL Injection Match
      • Size Constraint
      • Cross-site Scripting Match
    • Cloud HSM = Hardware Security Module
    • Certificate Manager
  • Management Tools
    • CloudWatch = Monitor
    • CloudFormation = Use templates to create infrastructure stacks
      • Use “CloudFormer” to create a template of your existing infrastructure to capture and redeploy applications you already have running
    • CloudTrail = track user & API activity
      • By default, log files are stored indefinitely
    • Config = Track resources & inventory changes (not in test)
    • OpsWorks = automation
      • Orchestration service that uses Chef
      • Chef consists of recipes to maintain a consistent state
      • Look for “chef”, “recipes”, “cookbook” in exam & think Opsworks
    • Service Catalog = not in test
    • Trusted Advisor = scans environment for ways to save money & increase security
  • Application Svcs
    • API Gateway = not in test
    • AppStream = AWS version of XenApp
    • CloudSearch = Managed search solution
    • Elastic Transcoder = Media transcoding service, change media files from source format to destination format
    • SES = Simple Email Service = send/receive emails
    • SQS = Simple Queue Service, a way of decoupling infrastructure
    • SWF = Simple WorkFlow Service
  • Dev Tools (not in test)
    • CodeCommit = “Github”
    • CodeDeploy = automates code deployment
    • CodePipeline = build, test, deploy code
  • Mobile Svcs (not in test, except for SNS)
    • Mobile Hub = test mobile apps
    • Cognito = save mobile user data in AWS cloud
    • Device Farm = test against real smartphones & tablets in AWS cloud
    • Mobile Analytics =
    • SNS = big topic in exam, Simple Notification Service. Way to send notifications from cloud
  • Enterprise Applications
    • WorkSpaces = VDI
      • Replaces Windows PC in the cloud (PCoIP)
      • Runs Windows 7, provided by Windows Server 2008 R2
      • Are persistent (EBS)
      • All data on D drive backed up every 12 hours
      • Do not need an AWS account to login to workspaces
      • Don’t need an existing AD domain, can use free client app
      • Can integrate with existing AD domain
      • By default:
        • Users can personalize their WorkSpaces with wallpaper, icons, shortcuts, etc..
        • Users have local admin access to install apps
    • WorkDocs = DropBox for enterprise
    • WorkMail = Exchange
  • IoT
    • Internet of Things = not in test
Identity Access Management (IAM)
  • Central control of AWS account
  • Share access
  • Granular permissions of accounts/groups/roles/policies
  • Identity Federation (AD, Facebook, LinkedIn, etc…)
  • MFA = Multi Factor Authentication
  • Temp access for users/devices/services
  • Pwd rotation policy highly customizable
  • Policies = JSON key/value pairs
  • IAM is universal, applies to all regions consistently
  • New Users have no permissions when 1st created
  • New Users are assigned an access key ID & secret access key when first created, only viewable once so download it & secure!
  • Always setup MFA on root
  • Integrated with AWS marketplace
S3
  • Secure, durable, highly scalable object storage. “Unlimited storage”. A hard drive in the cloud.
  • Object based NOT block based storage (no OS or DBs -> that’s Elastic Block Storage (EBS)). i.e. allows you to upload files
  • 0 byte to 5Tb file size
  • Files are stored in buckets
  • S3 is a universal namespace, each one must be unique:
  • EXAM Tips
    • Read after Write consistency for PUTS of new Objects
    • Eventual consistency for overwrite PUTS and DELETES as it can take time to propagate
  • S3 = Object based. Objects consist of the following:
    • Key = name of the object
    • Value = the data
    • Version ID (for versioning)
    • Metadata (tags)
    • Subresources
    • Access Control Lists (ACLs)
  • 99.99% availability
  • 99.999999999% durability
  • Tiered storage
  • Lifecycle mgmt.
    • Can be used in conjunction with versioning
    • Can be applied to both current & previous versions
    • Actions:
      • Transition to S3-IA (128Kb & 30 days after creation)
      • Archive to Glacier (30 days after S3-IA, if relevant)
  • Encryption, ACLs & Bucket Policies
  • Storage Tiers
    • S3
      • 99.99% availability
      • 99.999999999% durability
      • Redundant, designed to sustain loss of 2 facilities concurrently
    • S3-IA (infrequently accessed)
      • 99.9% availability
      • 99.999999999% durability
      • Lower fee than S3, but charged a retrieval fee
    • S3-RRS (Reduced Redundancy Storage)
      • 99.99% availability
      • 99.99% durability
    • Glacier
      • Very cheap (as little as $0.01 GB/mo.)
      • Used for archive only
      • Takes 3-5 hours to restore from Glacier
  • Versioning
    • Stores all versions of an object (including all writes and deletes)
    • Great backup tool
    • Cannot disable versioning once enabled, but you can suspend
    • Integrates with lifecycle rules
    • Can use MFA delete capability, so that you can’t delete without MFA
    • Cross Region Replication requires versioning – only applies to files manipulated *after* CRR is turned on
    • Can take up a LOT of space on files that change a lot (because it stores each changed version)
S3 – Security & Encryption
  • By default, all new buckets are PRIVATE
  • 2 types of access control for buckets
    • Bucket policies
    • ACLs
  • Buckets can be configured to log all requests
    • Can be done to another bucket or to another AWS account
  • Encryption – 4 methods
    • In transit – information to/from bucket
      • Uses SSL/TLS
    • At rest:
      • Server Side Encryption (SSE)
        • S3 Managed keys – SSE-S3
        • AWS Key Management Service, Managed Keys – SSE-KMS
          • Provides usage audit trail
        • SSE w/ Customer Provided Keys – SSE-C
    • Client Side Encryption – the customer encrypts data prior to uploading to bucket
CloudFront – CDN (Content Delivery Network)
  • Edge Location – Where the content will be cached (different from Region or AZ)
    • Not just read only, can write to them too.
    • Objects are cached for the life of the TTL (default 24 hours)
    • Can clear cached objects, but you will be charged
  • Origin – Where the original server content is located (S3 Bucket, EC2 instance, Route53, or ELB for AWS)
  • Not faster for the 1st user, but faster for every other subsequent user
  • Can be used for static, dynamic, streaming & interactive content
  • Requests are automagically routed to nearest Edge Location
  • Optimized to work well with other AWS services (duh)
  • Also works with non-AWS origin servers (the “definitive version”)
  • 2 types of Distributions:
    • Web Distribution – Used for websites
    • RTMP Distribution – used for media streaming
  • CloudFront options
    • Restrict Viewer Access – restrict using signed URLs or signed cookies
Storage Gateway
  • Connects on-prem software appliance with AWS storage to provide seamless & secure between an org’s on-prem IT environment & AWS storage infrastructure.
  • Asynch replication backed up to S3 as EBS snapshots
  • Data is stored within a single region (user specified)
  • Software appliance is supported on VMware or Hyper-V
  • 3 types of storage gateways:
    • Gateway Stored Volumes (cloud is backup)
      • Keep entire data set on-prem & asynch backed up to S3
      • Create storage volumes up to 16TB in size & mount them as iSCSI devices
      • Used for offsite backups
      • Constantly replicating changes up to S3 in the form of Amazon EBS snapshots
    • Gateway Cached Volumes (cloud is primary)
      • Only most frequently accessed data is stored on-prem, entire data set is stored in S3
      • Using S3 as your SAN array
      • Create storage volumes up to 32TBs in size & mount them as iSCSI devices
      • If you lose internet access, you lose access to all your data
    • Gateway Virtual Tape Library (VTL)
      • Limitless collection of virtual tapes
      • Up to 10 virtual tape drives per gateway
      • Exposes iSCSI interface so populat backup application (Netbackup , Backup Exec, Veeam, ect..) can point directly to VTL
  • Pricing:
    • Only pay for what you use, 4 pricing components:
      • Gateway usage (per gateway per month)
      • Snapshot storage usage (per GB per month)
      • Volume storage usage (per GB per month)
      • Data xfer out (per GB per month)
Snowball (Import/Export) 2 Types:
  • Import/Export Disk
    • You ship your disks to AWS site of your choice
    • Import into S3, Glacier, or EBS
    • Export from S3 
  • Import/Export Snowball
    • Available in US, EU(Ireland) & APAC(Sydney)
    • 50TB or 80TB models available
    • 256-bit encryption
    • TPM ensures chain-of-custody
    • Import into S3 only
    • Export from S3
S3 Transfer Acceleration (probably not in exam yet)
  • Use Edge Network to accelerate uploads to your S3 bucket
  • Better performance the further you are away from your bucket
  • Incurs an additional fee
EC2 (Elastic Compute Cloud) – “A web service that provides resizable compute capacity in the cloud. Reduces time required to obtain & boot new server instances to minutes allowing the ability to quickly scale capacity both up and down.”
Pricing models:
  • On Demand – pay fixed rate by the hour with no commitment
    • Best for burst need servers & unpredictable workloads that cannot be interrupted
    • For users that want flexibility of EC2 w/out up-front payments or long-term commitment
    • Test/Dev for apps running on EC2 for the 1st time.
    • Supplement reserved instance servers (for extra temporary server load)
  • Reserved – 1 or 3 year term. Discount compared to On Demand, the longer your contract, the more you save.
    • Best for “steady state” systems that you’ll always have running
    • Apps that need reserved capacity, steady state or predictable usage
      • Domain Controllers
      • 1st web server
  • Spot – Allows you to bid for whatever price you want to pay for instance capacity (by hour).
    • When your bid = spot price, you get a server
    • When spot price exceeds your bid, you lose server with 1 hour warning
    • Best used for grid computing where instances are disposable & applications have flexible start/stop times
    • If spot instance is terminated by EC2, you don’t get charged for partial hour of usage. If *you* terminate, you’ll get charged for the full hour.
EC2 Instance Types:
Family
Speciality
Use Case
T2
Lowest Cost, Gen Purpose
Web Svr, small DB
M4
Gen Purpose (Main)
App
M3
Gen Purpose (Main)
App
C4
Compute Optimized
High CPU App/DB
C3
Compute Optimized
High CPU App/DB
R3
Mem Optimized (RAM)
High Mem App/DB
G2
Graphics
Vid Encoding, 3D Apps, Streaming
I2
High Speed Storage (IOPS)
NoSQL DBs, Data Warehousing
D2
Dense Storage
File srv, Hadoop
EBS (Elastic Block Storage) – Storage volumes that are attached to EC2 instances (think VMDKs)
  • Can’t attach 1 EBS instance to 2 EC2 instances (use EFS for that)
  • Can attach multiple EBS instances to 1 EC2 instance
    • How to “grow” an EBS volume:
      • Detach the original Amazon EBS volume.
      • Create a snapshot of the original Amazon EBS volume’s data in Amazon S3.
      • Create a new Amazon EBS volume from the snapshot, but specify a larger size than the original volume.
      • Attach the new, larger volume to your Amazon EC2 instance in place of the original. (In many cases, an OS-level utility must also be used to expand the file system.)
      • Delete the original Amazon EBS volume.
  • Placed in specific AZs & automatically replicated
  • EBS 3 Volume Types
    • General Purpose SSD (GP2)
      • 99.999% availability
      • Ratio of 3 IOPs per GB & ability to burst up to 3k IOPS for short periods for volumes under 1Gb.
      • Use if you need up to 10k IOPS
    • Provisioned IOPS SSD (I01)
      • For I/O intensive apps (large DBs).
      • Use if you need more than 10k IOPS
    • Magnetic (standard)
      • Cheapest
      • Good for infrequently accessed data (fileservers)
*Know how to create a VPC from memory for exam!*
  • When creating an AMI, on Step 4(Add storage) “Delete on Termination” is checked and not encrypted by default (i.e. Termination protection is turned off by default):
  • On an EBS-backed instance, the default action is for the root EBS vol to be deleted when the instance is terminated.
  • Root volumes cannot be encrypted by default, you’ll need a 3rd party tool (bit locker, etc) to encrypt root vols.
Security Group Basics:
  • All inbound traffic is blocked by default (except for ssh for listros and rdp for windows)
  • All outbound traffic is allowed by default
  • Can edit security groups on the fly. Edits take effect immediately.
  • To install Apache on AWS AMI:
    • yum install httpd –y
    • service httpd status
    • service httpd start
    • chkconfig httpd on
  • Can’t add a rule to deny a specific protocol inbound or outbound
  • Security groups are stateful:
    • If you allow a protocol inbound, automatically it’s added to outbound
  • Can have any # of instances in a security group
Volumes vs Snapshots
  • Volume
    • A volume is a virtual hard disk (think VMDK)
    • Volumes exist on EBS
    • If you take a snapshot of a volume, this will store that volume on S3
  • Snapshot
    • Point in time copy of a volume
    • Exists on S3
    • Are incremental, only the blocks that have changed since the last snap are moved to S3
    • 1st snap takes some time to create
    • Can use snap to create a new volume & change the disk type (magnetic -> GP2 or IO1 or any other combination)
    • If you want to snap a root volume, you should stop the instance before taking snap
      • If you don’t, AWS will stop it prior to taking snap.
Go into EC2 -> Volumes -> create volume (make sure it’s in the same AZ as your server!) -> Actions -> attach to server.
Use lsblk to view disks to confirm new volume attached.
Use file –s /dev/xvdf to make sure it’s clean
Use mkfs –t ext4 /dev/xvdf to make file system, then mkdir /fileserver to create directory, & mount /dev/xvdf/fileserver to mount
Volumes vs Snapshots – Security
  • Snapshots of encrypted vols are encrypted automatically
  • Vols restored from encrypted snaps are also automatically encrypted
  • You can share snaps, but only if they are unencrypted
    • They can be shared to other AWS accounts or made public
RAID, Volumes & Snapshots
  • RAID = Redundant Array of Independent Disks
    • RAID 0 – Striped, no redundancy, good performance
    • RAID 1 – mirrored, redundancy
    • RAID 5 – good for reads, bad for writes, AWS does not recommend ever putting RAID 5’s on EBS
    • RAID 10 – Striped & Mirrored, good redundancy, good performance
  • Why create a RAID in AWS?
    • Not getting Disk I/O that you require from GP2 or IO1 on a single volume.
  • How do you snap a RAID array?
    • Stop the app from writing to disk… how?
    • Take application consistent snap using one of these 3 methods:
      • Freeze file system
      • Unmount RAID array
      • Shut down EC2 instance
Create an AMI (Amazon Machine Image)
  • AMI = template VM
  • Are regional. You can only launch an AMI from the region where it’s stored. You CAN copy AMI’s to other regions using the command line/console/API.
  • Contains:
    • Template for root volume for the instance (OS, application servers, apps, etc)
    • Launch permissions that control with AWS accounts can use the AMI to launch instances
    • Block device mapping that specifies which volumes to attach when launching instance
  • By default, any AMI you create is private. You can modify image permission to make it public.

  • Read these articles on how to harden & clean up an AMI before making public!
AMI Types (EBS vs Instance Store)
  • You can select your AMI based on:
    • Region
    • OS
    • Architecture (32 or 64 bit)
    • Launch Permissions
    • Storage for the Root Device (root vol), 2 types:
      • Instance Store (ephemeral storage)
        • Can’t “stop” an instance of this type, only reboot or terminate. If the underlying host fails, you will lose data.
        • You can reboot without losing data, if you stop the instance, the data will be wiped.
        • “Ephemeral storage” means exactly that, not persistent
        • The root device for an instance launched from the AMI is an instance store volume created from a template stored in S3
        • Cannot be detached and reattached to other EC2 instances
      • EBS backed volumes
        • Are persistent
        • The root device for an instance launched from the AMI is an EBS volume created from an EBS snapshot
        • Can be stopped, you will not lose data if the underlying host fails.
        • Can be detached and reattached to other EC2 instances
        • By default, both root vols will be deleted on termination, but you can choose to keep an EBS vol on termination, not for ephemeral.
Elastic Load Balancers (ELB)
  • ELB is never given a static IP address, just DNS name.
  • ELBs can be “In Service” or “Out of Service”
  • Thresholds
    • Unhealthy Threshold = how many intervals with no response before flagging as Out of Service
    • Healthy Threshold = how many intervals with response before flagging as In Service
  • Support the following X-Forwarder headers:
    • X-Forwarded-For
    • X-Forwarded-Proto
    • X-Forwarded-Port
CloudWatch – Performance Monitoring Service
  • Standard monitoring = 5 minutes
    • Turned on by default
  • Detailed monitoring = 1 minute
  • Monitors the hypervisor, NOT the guest OS
    • Does not monitor memory
  • Dashboards – create/configure widgets to monitor your environment
  • Alarms – notify when a given threshold is hit
  • Events – automatically respond to state changes in your AWS resources
  • Logs – aggregate, monitor & store logs. Agent installed onto EC2 instances
  • You can only assign a role to an EC2 instance during its creation!
  • AWS command line preinstalled on the AWS AMI
  • Commands:
    • Aws configure
      • Input access key, Secret Access key, default region name (in doc above) & output format (I just hit enter)
    • Aws s3 help
      • Make Bucket = mb
      • Remove Bucket = rb
  • If you use roles, you don’t have to store your credentials on your EC2 instance (which is a security risk)
IAM – Roles
  • Roles can only be assigned to an EC2 instance when you are launching it.
  • Roles are more secure than storing access keys on individual EC2 instances
  • Roles are easier to manage
  • They are universal, can be used in any region/AZ
  • Useful for:
    • Federated (non-AWS) user access
      • Microsoft AD, LDAP, Kerberos
      • Can create trust if org supports SAML 2.0
    • Cross-Account Access
      • Multiple AWS accounts
    • Applications running on EC2 instances that need access to other AWS resources
      • EC2 instance hitting an S3 bucket or DynamoDB table
Bash Scripting
  • Write a script that EC2 instance will run when 1st being provisioned
    • Install apache
    • Run updates
    • Move file from S3 to apache dir to create website
  • How to write the bash script
    • #!/bin/bash
    • Yum install httpd –y
    • Yum update –y
    • Aws s3 cp s3://<BUCKETNAME>t/index.html /var/www/html
    • Service httpd start
    • Chkconfig httpd on
  • Provision an AWS AMI instance per usual, but in the advanced section put in the above script

Instance Metadata –
  • How to access instance metadata from within an EC2 instance. From CLI:
    • Sudo su
      • This could be triggered from a bash script & returns a bunch of different variables, which can then be used to perform various functions:
        • Write data to an html page
        • Trigger a lambda function to update DNS
        • Whatever else you can think of J

Auto scaling Groups
  • Have to have a launch configuration to have an auto scaling group
  • Can create rules to spin-up and/or shut down instances based on monitor triggers
  • Deleting an auto scaling group will automatically delete any instances it created
EC2 Placement Groups
  • A logical grouping of instances within a single AZ.
    • Can’t span AZs (duh)
  • Enables applications to participate in low-latency, 10 GBps network
  • Recommended for apps that benefit from low latency networks, high network throughput, or both
    • Grid computing
    • Hadoop clusters
  • Name must be unique within your AWS account
  • Only certain types of instances can be launched in a placement group
    • Compute Optimized
    • GPU
    • Memory Optimized
    • Storage Optimized
  • AWS recommends homogenous instances within a placement group (size & family)
  • Can’t merge placement groups
  • Can’t move an existing instances into a placement group. You *can* create an AMI from your existing instance THEN launch a new instance from that AMI into a placement group… if you really wanted to.
Elastic File System (not in exam yet)
  • File storage for EC2 instances
  • Elastic capacity
  • Can mount multiple EC2 instances to 1 EFS “volume”
  • Supports NFSv4 & thousands of connections
  • Only pay for the storage you use (don’t need to pre-provision)
  • Scales up to PBs
  • Data is stored across multiple AZs within a region
  • Read after write consistency
  • File based storage
Lambda concepts
  • Compute service that runs your code in response to events and it automatically manages the underlying compute resources for you
  • Can automatically run code in response to events
    • Modifications to objects in S3 buckets
    • Messages arriving in Kinesis stream
    • Table updates in DynamoDB
    • API call logs created by CloudTrail
    • Etc…
  • A new abstraction layer – run code without worrying about infrastructure at all
  • Javascript is the supported programming language
  • 99.99% availability for the service and the functions it operates
  • 1st 1 million requests are free, $0.20 per 1 million requests afterwards
Route53 (DNS)
  • IPv6 not fully supported yet.
  • Alias records work like CNAME records
    • Used to map resource record sets in your hosted zone to ELB, CloudFront distributions, or S3 buckets that are configured as websites.
    • Difference – a CNAME can’t be used for naked domain names (i.e. w/out “www”), you can with A record or Alias.
    • Automatically recognizes changes in the record sets
  • ELBs don’t have a pre-defined IPv4 address, resolved using DNS
    • This can be an issue because naked domain names need an IP address.
    • Hence the need for Alias records
  • Given a choice, always choose an Alias record because you won’t incur additional charges (as you would with a CNAME)
DNS Routing Policies:
  • Simple
    • Default when you create a new record set
    • Most commonly used when you have a single resource that performs a given function (i.e. 1 webserver)
    • No built-in intelligence
  • Weighted
    • Split traffic based on weighted assignments (10% to X, 90% to Y)
    • Different regions, ELBs, AZs, etc.
    • Commonly used when testing a new website & you only want a small subset to see the new site
  • Latency
    • Route traffic based on lowest network latency for your end user
    • Need to create a latency resource record set for the EC2 or ELB resource in each region you want participating.
    • Great for improving global page load times
  • Failover
    • Used when you want to create an active/passive set up.
    • Route53 will monitor health of primary site using a health check (which monitors your end points)
  • Geolocation
    • You choose were traffic will be sent based on location of users
    • Ex. All EU users get routed to servers w/ local language and prices in Euros
Databases
  • RDS – Been around since the 70s. Database: tables, rows, fields (columns) -> think spreadsheet
  • DynamoDB – non-relational databases (No SQL)
    • Database:
      • Collection     = Table
      • Document     = Row
      • Key/Value pairs    = Fields
  • ElastiCache
    • web service that deploys, operates & scales an in-memory cache. Improves performance of web apps by retrieving info from RAM instead of disk.
    • Supports 2 open source in-mem caching engines
      • Memcached
      • Redis
    • Caches most consistently queried data
  • Redshift (data warehousing)
    • OLAP
    • Used for BI. Cognos, Jaspersoft, SAP Netweaver
    • Used to pull in large & complex data sets. Usually used to do queries on data.
  • DMS (database migration services)
    • Migrate your prod DB into AWS
    • AWS manages all the complexities of migration like data type transformation, compression & parallel xfer
    • Schema conversion tool:
      • Convert source DB to a different target DB (Oracle -> Aurora, etc…)
  • Backups, Multi-AZ & Read Replicas
    • Backups (2 types):
      • Automated
        • Recover DB to any point in time within retention period (between 1 – 35 days)
        • Point in time recovery down to a second, up to the last 5 minutes
        • Enabled by default
        • Backup data is stored in S3
        • Free backup storage equal to size of DB
        • Backups are taken within a defined window, retention period up to 35 days
        • During backup, I/O suspended (typically a few minutes)
          • This can be avoided if you go Multi-AZ as the backup is taken of the standby
      • DB Snapshots
        • Done manually (user initiated), full backup
        • Stored even after you delete the original RDS instance, until you explicitly delete them
        • When you restore either automated or snap, the restored version will be a new RDS instance with a new endpoint
    • Encryption
      • At rest is supported for MySQL, Oracle, SQL, PostgreSQL & MariaDB
      • Done using AWS KMS
      • Once your RDS instance is encrypted at rest – underlying storage, backups, read replicas and snaps are also encrypted
      • Turning on encryption for an existing instance isn’t supported… create a new encrypted instance & migrate data to it
    • Multi-AZ
      • Primary RDS instance uses synchronous replication to an RDS in a diff AZ.
      • Automatic failover, same DNS point, AWS handles replication
      • Disaster Recovery only, not performance improvement
      • Only in:
        • SQL Server
        • Oracle
        • MySQL Server
        • PostgreSQL
        • MariaDB
    • Read Replica
      • Uses asynchronous replication to create up to 5 read-only DB copies
      • Used for performance improvement & Scaling, not DR:
        • Write to prod, read from read replicas
      • Must have automatic backups turned on
      • You can have read replicas OF read replicas, but watch out for latency if you do this.
      • Each read replica will have it’s own DNS end point.
      • Cannot have read replicas that have Multi-AZ but you CAN create read replicas of Multi-AZ source DBs
      • Can break replication & turn a read replica to it’s own source DB
      • Only in:
        • MySQL Server
        • PostgreSQL
        • MariaDB
    • DynamoDB vs RDS
      • DynamoDB offers “push button” scaling -> scale DB on the fly with no downtime
      • RDS isn’t as easy -> usually need to create bigger instance size manually or add a read replica
  • DynamoDB
    • Fast, flexible NoSQL DB service.
    • Used for apps that need consistent, single-digit millisecond latency at any scale
    • Fully managed & supports document and key/value data models
    • Stored on SSD storage
    • Spread across 3 “geographically distinct” data centers
    • Multiple consistency models:
      • Eventually consistent reads (default)
        • Consistency usually reached within 1 second (best read performance)
      • Strongly consistent reads
        • Returns a result that reflects all writes that got a successful response prior to the read
        • Use this if your app needs data back immediately & in less than 1 second.
    • Pricing (not in exam):
      • Write throughput $0.0065 per hour every 10 units
      • Read throughput $0.0065 per hour every 50 units
      • Storage = $0.25 per GB per month
      • Expensive for writes, cheap for reads
  • Redshift
    • Fast (10 times faster), fully managed petabyte-scale data warehouse service
    • Can start small for $0.25 per hour with no commitments & scale up to PB or more for $1,000 per TB per year.
    • OLAP transactions
    • Data warehousing DBs us diff type of architecture from both a DB perspective & infrastructure layer.
    • 2 Configurations:
      • Single node (160Gb)
      • Multi-node
        • Leader Node (manages client connections and receives queries)
        • Compute Node (store data & perform queries and computations). Up to 128 Compute Nodes
    • Columnar Data Storage – instead of rows, redshift organizes data by column
      • Only columns involved in the queries are processed
      • Columnar data is stored sequentially on the storage media
      • Block size of 1MB for columnar storage
      • Therefore requires far fewer I/Os, greatly improving performance
    • Advanced Compression
      • Columnar data can be compressed much better than row based data
      • Redshift automatically samples data & chooses the best compression scheme
    • Massively Parallel Processing (MPP):
      • Automatically distributes data & query load across all nodes & newly added nodes
    • Pricing:
      • Compute Node Hours
        • 1 unit per node per hour
      • Backup
      • Data Transfer
    • Security
      • Encrypted in transit using SSL
      • At rest using AES-256
      • By default RedShift does it’s own key mgmt.
        • Can manage keys through HSM (hardware security modules) or KMS if you want
    • Only available in 1 AZ
      • Can restore snaps to new AZs in the event of an outage
    • Good choice if mgmt. runs lots of OLAP transactions & it’s stressing the DB
    • Think Business Intelligence (BI)
  • Elasticache
    • Caches things – if your app is constantly going to a DB to pull the same data over and over, you can cache it for faster performance
    • Used to improve latency and throughput for read-heavy app workloads (social networks, gaming, media sharing) or compute heavy workloads (recommendation engine)
    • Improves application performance by storing critical pieces of data in mem for low-latency access.
    • Types of elasticache
      • Memcached
        • Widely adopted mem object caching system.
      • Redis
        • Open source in-mem key/value store.
      • Supports master/slave replication & multi-AZ to achieve cross AZ redundancy
    • Good choice if your DB is read heavy & not prone to frequent changing
  • Aurora
    • MySQL compatible RDS DB engine
    • Speed & availability of commercial DBs
    • Simplicity & cost-effectiveness of open source DBs
    • 5x better performance than MySQL @ 1/10th the price of commercial DB w/ similar performance & availability
    • Big challenge to Oracle
    • Scaling capabilities:
      • Start w/ 10Gb, scales in 10Gb increments up to 64Tb
      • Compute scales up to 32vCPUs & 244Gb of mem
      • 2 copies of DB in each AZ w/ a min of 3 AZs (6 copies of data)
      • Can handle loss of 2 copies w/out affecting write availability
      • Can handle loss of 3 copies w/out affecting read availability
      • Storage is self-healing. Blocks & disks are constantly scanned & repaired
    • Replica features:
      • Aurora Replicas (currently 15)
      • MySQL read replicas (currently 5)
VPC (Virtual Private Cloud)
  • For the exam know how to build a custom VPC from memory
    • Create VPC
      • Define IP range (automatically creates default route table)
      • Create subnets (automatically creates route table & nACL)
        • Largest = /16, Smallest = /28
        • AWS reserves the 1st 4 and last 1 IP address of any subnet, so /28 = 11 useable IPs
      • Create IGW
        • By default it’s detached, need to manually attach it to VPC
      • Create custom route table & attach IGW to it
      • Associate public subnet(s) to use new route
      • Launch 1 instance per subnet
      • Provision EC2 NAT instance
        • Create security group for NAT instance
  • VPC = Think of it as a Virtual Datacenter
    • By default you are allowed 5 VPCs per region
    • Logically isolated section of AWS where you can launch AWS resources in a virtual network of your own definition
    • You control the network environment: IP address range, subnets, routing tables, gateways, etc
  • Default VPC vs Custom VPC
    • Default is user friendly, can deploy instances right away
    • All subnets in default VPC have an internet gateway attached
    • Each EC2 instance has both a public & private IP address
    • If you delete default VPC, you have to call AWS to get it back
  • VPC Peering
    • Connect 1 VPC to another VPC via direct network route using private IP addresses
    • Instances behave as if they were on the same private network
    • You can peer VPC’s with other AWS accounts & with other VPC’s in the same account within a single region
    • AWS uses the existing infrastructure of a VPC to create a VPC peering connection. 
    • It is not a gateway or a VPN connection.
    • It does not rely on a separate piece of hardware
    • No SPoF for communication or bandwidth bottleneck
    • Peering is done in a star configuration. VPC A ßà VPC B ßà VPC C = A cannot talk to C unless you connect directly (no transitive peering)
    • Peers cannot have matching or overlapping CIDR blocks
  • By default when you create a VPC it will automatically create a route table
  • If you choose dedicated tenancy for your VPC, any instances you create in that VPC will also be dedicated
  • 1 subnet = 1 AZ, you cannot have subnets cross AZ
  • Don’t forget to add internet gateway
    • 1 IGW per VPC
    • Need to attach IGW after you create it
  • Need to create InternetRouteTable if you want VPC to communicate in/out 

    • Once you’ve created your IGW, any subnet associations you make to it will be internet accessible:

    • A security group can stretch across multiple Regions/AZs where a subnet cannot
  • VPC Flow Logs:
    • Enables you to capture information about the IP traffic going to and from network interfaces in your VPC
    • Data is stored using Amazon CloudWatch Logs, you can view and retrieve its data in Amazon CloudWatch Logs.
    • Help with a number of tasks:
      • Troubleshoot why specific traffic is not reaching an instance
      • Diagnose overly restrictive security group rules
      • Security tool to monitor the traffic that is reaching your instance.
Network Address Translation (NAT)
  • Allows your instances that do not have internet access the ability to access the internet via a NAT server instance
  • create security group
  • allow inbound & outbound on HTTP and HTTPS
  • provision NAT inside public subnet
  • On a NAT instance, you need to change source/destination check to disabled
  • Set up route on private subnet to route through NAT instance
Access Control Lists (ACLs)
  • A numbered list of rules (in order, lowest applies first)
  • Put down network access lists across the entire subnet
  • Over rules security groups
  • Acts as a basic firewall
  • VPC automatically comes with an ACL
  • When you create a new ACL, by default everything is DENY
  • Only one ACL per subnet, but many subnets can have the same ACL
Application Services
SQS – most important service going into exam
  • Read FAQ for SQS for exam: https://aws.amazon.com/sqs/faqs/
  • A distributed message queueing service that sits between a “producer” and “consumer” to quickly and reliably cache that message.
  • Allows you to decouple the components of an app so that they can run independently.
  • Eases message management between components
  • Any component can later retrieve the queued message using SQS API
  • Queue resolves issues if:
    • The producer is producing work faster than consumer is processing
    • Producer or consumer are only intermittently connected to network
  • Ensures delivery of each message at least once
  • Supports multiple writers and readers on the same queue
  • Can apply autoscaling to SQS 
  • A single queue can be used by many app components with no need for those components to coordinate amongst themselves to share the queue
  • SQS does NOT guarantee first in, first out (FIFO) delivery of message
    • If you want this, you need to place sequencing information in each message so that you can reorder the messages after they come out of queue
  • SQS is a pull based system
  • 12 hour visibility time out by default
  • Engineered to provide “at least once” delivery of mgs, but you should design your app so that processing a message more than once won’t create an error
  • Messages can contain up to 256KB of text in any format
  • Billed at 64KB “chunk” – a 25kKB msg will be 4 x 64KB “chunks”
  • 1st 1 million SQS requests per month are free
  • $0.50 per 1 million requests per month thereafter
  • A single request can have from 1 to 10 messages, up to a max total payload of 256KB
  • Each 64KB ‘chunk’ of payload is billed as 1 request.
    • Ex: 1 API call with a 256KB payload is billed as 4 requests
SWF – Simple Workflow Service
  • Makes it easy to coordinate work across distributed app components
  • Enables apps to be designed as a coordination of tasks
  • Tasks represent invocations of various processing steps in a app which can be performed by:
    • Executable code
    • Web service calls
    • Human actions
    • Scripts
  • Amazon uses SWF to process orders on the amazon website to get you your stuffs
  • SWF vs SQS
    • SQS has a retention period of 14 days, SWF up to 1 year for workflow executions
    • SWF presents task-oriented API, SQS = message-oriented API
    • SWF ensures a task is assigned only once and never duplicated, with SQS you need to handle the potential for duplicate messages
    • SWF keeps track of all the tasks & events in an application. With SQS you need to implement application-level tracking, especially if you have multiple queues.
  • SWF Actors (3 types):
    • Workflow Starters – an app that can initiate a workflow (amazon.com front end when placing an order)
    • Deciders – control the flow of activity tasks (if cc declined – decide to send to alternative payments page)
    • Activity workers – carry out tasks (payment now successful, go pull widget off shelf & mail it)
SNS – Simple Notification Service
  • Web service to setup, operate & send notifications from AWS.
  • Scalable, flexible, cost-effective way to publish messages from an app & deliver them to subscribers or other apps
  • Push notification to Apple, Google, Fire OS, Windows devices, etc..
  • Can deliver via SMS text messages, email, SQS queues, any HTTP endpoint
  • Can also trigger Lambda functions
  • SNS Subscribers:
    • HTTP/S
    • Email/Email-JSON
    • SQS
    • Application
    • Lambda
  • Allows you to group multiple recipients using topics
  • One topic can support delivery to multiple endpoints types
    • “Autoscale change” to my phone, my email etc… all properly formatted for the endpoint
  • All messages published to SNS are stored redundantly across multiple AZs
  • Instantaneous, push-based deliver (no polling)
  • Simple APIs & easy integration with apps
  • Flexible message delivery over multiple transport protocols
  • Pay as you go model with no up-front costs
  • Mgmt console offers simple point/click interface
  • SNS vs SQS
    • Both messaging services in AWS
    • SNS – Push
    • SQS – Polls (pulls)
  • Pricing:
    • $0.50 per 1 million SNS requests
    • $0.06 per 100,000 notification deliveries over HTTP
    • $0.75 per 100 notification deliveries over SMS
    • $2.00 per 100,000 notification deliveries over email
Elastic Transcoder
  • Media transcoder in the cloud
  • Converts media file from original source format into different formats that will play on different endpoint devices
  • Provides transcoding presets for popular output formats
    • Don’t need to guess about which settings work best on particular devices
  • Pay based on the minutes that you transcode & the resolution at which you transcode
  • https://read.acloud.guru/easy-video-transcoding-in-aws-7a0abaaab7b8#.eepluawzo
White Paper Breakdown:
What is cloud computing? On demand delivery of IT resources and apps via the Internet w/ pay-as-you-go pricing. Cloud providers maintain the network-connected hardware while the consumer provisions and use what you need via web applications.
6 Advantages of Cloud:
  1. Trade capex for “variable expense”
  2. Benefit from economies of scale
  3. Stop guessing about capacity
  4. Increase speed & agility
  5. Stop spending money running & maintaining datacenters
  6. Go global in minutes
  • State of the art electronic surveillance and multi factor access control systems
  • Staffed 24×7 by security guards
  • Access is least privilege based
Shared Security Model – AWS is responsible for securing the underlying infrastructure. YOU are responsible for anything you put on or connects to the cloud
AWS responsibilities:
  • Infrastructure (hardware, software, networking, facilities)
  • Security configuration of it’s managed services (DynamoDB, RDS, Redshift, Elastic MapReduce, WorkSpaces)
Customer responsibilities:
  • IAAS – EC2, VPC, S3
  • Managed services – Amazon is responsible for patching, AV etc… but YOU are responsible for account mgmt. and user access. Recommended that MFA is implemented, SSL/TLS is used for communication, & API/user activity is logged using CloudTrail
Storage Decommissioning:
  • AWS uses NIST 800-88 to destroy data. All decommed magnetic storage devices are degaussed and physically destroyed.
Network Security:
  • Transmission Protection – Use HTTPS using SSL
  • For customers who need additional layers of network security, AWS provides VPCs & the ability to use an IPSec VPN between their datacenter & the VPC
  • Amazon Corporate Segregation – AWS production network is segregated from the Amazon corporate network by a means of a complex set of network security/segregation devices
  • DDoS mitigation
  • Prevent Man in the middle attacks (MITM)
  • Prevent IP Spoofing – the AWS controlled, host-based firewall will not permit an instance to send traffic with a source IP or MAC other than its own.
  • Prevent Port Scanning – Unauthorized port scans are a violation of T&Es. You must request a vulnerability scan in advance
  • Prevent Packet Sniffing by other tenants
AWS Credentials
  • Passwords
  • MFA
  • Access Keys
  • Key Pairs
  • X.509 certs
AWS Trusted Advisor
  • Inspects your AWS environment & makes recommendations to save money, improve performance & close security gaps:
  • Provides alerts for several of the most common security misconfigs:
    • Leaving certain ports open
    • Not creating IAM accounts for internal users
    • Allowing public access to S3 buckets
    • Not turning on user activity logging (AWS CloudTrail)
    • Not using MFA on your root AWS account
Instance Isolation
  • Instances on same physical machine are isolated from each other via the Xen hypervisor.
  • The AWS firewall resides within the hypervisor layer, between the physical network interface & the instances virtual interface.
    • All packets must pass through this firewall
  • Physical RAM is separated using similar mechanisms
  • Customer instances have no access to raw disk devices, only virtual disks
  • AWS proprietary disk virtualization layer resets every block of storage used by the customer
    • Ensures customer X data isn’t exposed to customer Y
  • Mem allocated to guest is scrubbed (zeroed out) by hypervisor when it becomes unprovisioned
    • Mem not returned to pool of free mem until scrubbing is complete
  • Guest OS
    • Instances are completely controlled by customer. AWS does not have any access rights or back doors to guest OSes
    • AWS provides the ability to encrypt EBS volumes & their snapshots with AES-256
  • Firewall:
    • EC2 provides a complete firewall solution. By default inbound is DENY-ALL
  • ELB – SSL Termination on the load balancer is supported
    • Allows you to ID the originating IP address of a client connecting to your servers, whether you are using HTTPS or TCP load balancing
  • Direct Connect:
    • Slower to provision than a VPN because it’s a physical connection
    • Bypass ISPs in your network path (if you don’t want traffic to traverse Internet)
    • Procure rack space within the facility housing the AWS Direct Connect location & deploy your equipment nearby.
    • Connect this equipment to AWS Direct Connect using a cross-connect
    • Use VLANs (802.1q) to use 1 connection to access both public (S3) and private (EC2 in a VPC) AWS resources
    • Available in
      • 10Gbps
      • 1Gbps
      • Sub 1Gbps groups purchased through AWS Direct Connect Partners
  • AWS mgmt. has a strategic business plan which includes risk identification & mitigation plans. This is re-evaluated at least bi-annually. 
  • AWS security regularly scans all Internet facing service endpoint IP addresses for vulnerabilities (these scans do not include customer instances)
  • Independent external vulnerability threat assessments are performed regularly by 3rd party security firms.
    • Not meant to replace a customer’s own vulnerability scans
  • SOC 1/SSAE 16/ISAE 3402
  • SOC2
  • SOC3
  • FISMA, DIACAP, & FedRAMP
  • PCI DSS Level 1 ß
    can take credit card information with PCI compliance (software needs to be compliant too)
  • ISO 27001
  • ISO 9001
  • ITAR
  • FIPS 140-2
  • HIPAA
  • Cloud Security Alliance (CSA)
  • Motion Picture Association of America (MPAA)
AWS Platform:
Storage Options in the Cloud: (2 docs?)
Architecting for the Cloud – Best Practices: http://d0.awsstatic.com/whitepapers/AWS_Cloud_Best_Practices.pdf
Business Benefits:
  • Almost 0 upfront infrastructure investment
  • JIT infrastructure
  • More efficient resource utilization
  • Usage-based pricing
  • Reduced time to market
Technical Benefits:
  • Automation – “Scriptable infrastructure”
  • Auto-scaling
  • Proactive scaling
  • More efficient dev lifecycle
  • Improved testability
  • DR/BC baked in
  • “Overflow” traffic to the cloud
Design for Failure:
  • Assume that hardware will fail & outages will occur
  • Assume that you will be overloaded with requests
  • By being a pessimist, you think about recovery strategies during design time, which helps you design an overall better system
Decouple your components:
  • Build components that do not have tight dependencies so that if 1 component dies/sleeps/is busy, the other components are built so as to continue work as if no failure is happening.
  • If you see decoupling in exam, think SQS
  • WebServer – SQS – AppServer – SQS – DBServer
Implement Elasticity:
  • Proactive Cyclic Scaling – periodic scaling that occurs @ fixed intervals (daily, weekly, monthly, quarterly) i.e. “Payroll Monday”
  • Proactive Event Scaling – when you are expecting a big surge of traffic (Black Friday, new product launch, marketing campaign)
  • Auto-scaling based on demand – Create triggers in monitoring to scale up/down resources
Secure Your Application:
  • Only have the ports open to/from your various stacks to allow communication, no more (duh)
Consolidated Billing
  • 1 paying account for all linked accounts in an org
  • Paying account gets 1 monthly bill
  • Paying account cannot access resources of the linked accounts
  • All linked accounts are independent of each other
  • 20 linked accounts for consolidated billing (soft limit)
  • Easy to track charges & allocate costs
  • Volume pricing discount, resources of all your linked accounts are added up for discounts
Resource Groups & Tagging
  • Tags = Key/Value pairs attached to AWS resources
  • Metadata
  • Tags can be inherited sometimes:
    • Autoscaling, CloudFormation, Elastic Beanstalk can create other resources
  • Resource Groups
    • Make it easy to group resources using the tags that are assigned to them
    • Contain info like:
      • Region
      • Name
      • Health checks
      • For EC2 – Public & Private IP addresses
      • For ELB – Port configs
      • For RDS – Database engine, etc.
    • Use tag editor to find/modify resources in large volumes
Active Directory Integration:
  • User browses to ADFS URL
  • User authenticates against AD
  • User receives a SAML assertion
  • User’s browser posts the SAML assertion to the AWS sign-in endpoint for SAML
  • User’s browser receives the sign-in URL and is redirected to the console
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