nealalan.github.io/aws-notes

[EDIT]

Outdated: This is from the first time I studied for the cert in 2018

TOC

• AWS Well-Architected Framework
• AWS Disaster Recovery Whitepaper
• Cheat Sheet - AWS Services Summary
• Cheat Sheet - Security & Identity Services
• Cheat Sheet - Network Services
• Cheat Sheet - Compute Services
• Cheat Sheet - Storage Services
• Cheat Sheet - Database Services
• Cheat Sheet - Analytic Services
• Cheat Sheet - Application Services
• Cheat Sheet - Mgmt Tools
• AWS Certified SysOps Admin - Associate
• AWS Certified Developer – Associate
• AWS Certified Security - Specialty Certification
• IAM - Identity & Access Management
• Cloudwatch

AWS Well-Architected Framework (June 2018 version)

Good Design Principles

• Stop guessing your capacity needs
• Test systems at production scale
• Automate to make architectural experimentation easier
• Allow for evolutionary architectures
• Drive architectures using data
• Improve through game days

The Five Pillars of the Well-Architected Framework

1. OPS: Operational Excellence
2. SEC: Security
3. REL: Reliability
4. PERF: Performance Efficiency
5. COST: Cost Optimization

1) OPS: Operational Excellence (Whitepaper)

Design Principles for Operational Excellence

• Perform operations as code
  • limit human error and enable consistent responses to events
  • define your entire workload (applications, infrastructure, etc.) as code and update it with code
• Annotate documentation
  • Annotated documentation can be used by humans and systems
  • Use annotations as an input to your operations code.
• Make frequent, small, reversible changes
  • Design workloads to allow components to be updated regularly to increase the flow of beneficial changes into your workload
  • Make changes in small increments that can be reversed if they fail to aid in the identification and resolution of issues
• Refine operations procedures frequently
  • As you evolve your workload, evolve your procedures appropriately
• Anticipate failure
• Learn from all operational failures (lessons learned)

3 Areas: 1) PREPARE

• Operational Priorities
  • teams need to have a shared understanding of your entire workload, their role in it, and shared business goals
  • use the resources provided by AWS Support
  • AWS Knowledge Center
  • AWS Discussion Forms
  • AWS Support Center
  • AWS Cloud Compliance - regulatory or compliance requirements
  • AWS Trusted Advisor - core set of checks that recommend optimizations for your environment
• Design for Operations
  • AWS CloudFormation - create version-controlled templates
  • AWS Developer Tools - Set up CI/CD pipelines using:
    • AWS CodeCommit, AWS CodeBuild, AWS CodePipeline, AWS CodeDeploy, AWS CodeStar
  • apply metadata using tags
  • capture logs in Amazon CloudWatch from:
    • AWS CloudTrail, AWS Lambda, VPC Flow Logs, CloudWatch Events, Amazon CloudWatch Logs API
  • use this log information to create a system-wide view of your operational status
    • CloudWatch Dashboards or third-party tools
  • AWS X-Ray traces user requests as they travel through your entire application
• Operational Readiness
  • use a consistent process (including checklists) to know when you are ready to go live
  • test your procedures, failure scenarios, and the success of your responses (Game Days)
  • create temporary parallel environments, which lowers the risk, effort, and cost of experimentation and testing
  • script procedures on your instances using AWS Systems Manager Run Command, Systems Manager Automation, and use AWS Lambda to script responses to events across AWS service
  • Automate your responses by triggering these scripts using CloudWatch Events
  • making baselines using AWS Config

3 Areas: 2) OPERATE

• Understanding Operational Health
  • implement CloudWatch Dashboards with business and technical viewpoints to make informed decisions
  • CloudWatch Logs
    • define baseline metrics to establish normal operating patterns
    • ingest into Amazon ES (Elasticsearch Service)
    • use the built-in support for Kibana to create dashboards and visualizations of your operational health
  • Amazon Elastisearch Service makes it easy to deploy, secure, operate, and scale Elasticsearch for log analytics, and application monitoring.
  • AWS Personal Health Dashboard provides alerts and remediation guidance when AWS is experiencing events that may impact you
  • AWS Service Health Dashboard provides up-to-the-minute information on AWS service availability
• Responding to Events
  • anticipate operational events, both planned (for example, sales promotions, deployments, and failure tests) and unplanned (for example, surges in utilization and component failures)
  • automate the execution of runbook and playbook actions on AWS.
  • create CloudWatch rules to trigger responses through CloudWatch targets:
    • Lambda functions, Amazon SNS topics, Amazon EC2 ECS tasks, AWS Systems Manager Automation
  • create CloudWatch alarms to perform one or more actions:
    • Amazon EC2 actions, Auto Scaling actions, send a notification to an Amazon SNS topic.
    • custom actions in response to an alarm, invoke Lambda through Amazon SNS notification.
    • Use Amazon SNS to publish event notifications and escalation messages to keep people informed
  • third-party systems through the AWS service APIs and SDKs
    • New Relic, Splunk, Loggly, SumoLogic, and Datadog.
  • Amazon Elastisearch Service
  • Amazon CloudWatch / Amazon CloudWatch Events
  • Amazon SNS
  • Auto Scaling for elasticity

3 Areas: 3) EVOLVE

• Learning from Experience
  • Amazon QuickSight is a business analytics service that makes it easy to build visualizations, perform ad-hoc analysis, and quickly get insights from your data
  • Amazon Athena is a serverless interactive query service that makes it easy to analyze data in Amazon S3
  • Amazon CloudWatch is used for the collection of logs and metrics and the creation of dashboards
• Share Learnings
  • AWS IAM - enables you to manage the sharing of resources within and across accounts
  • AWS CodeCommit provides a version-controlled repository for your operations as code
  • AWS Lambda enables the definition of operational procedures as code that can be shared across accounts
  • Amazon Machine Images (AMIs) are predefined operating system templates

Best Practices

• OPS 1: What factors drive your operational priorities?
  • Evaluate Business needs
  • Evaluate compliance requirements
  • Evaluate risk
• OPS 2: How do you design your workload to enable operability?
  • Share design standards
  • Design for cloud operations
  • Provide insights into workload behavior
  • Provide insights into customer behavior
  • Implement practices that reduce defects, ease remediation and improve flow
  • Mitigate deployment risks
• OPS 3: How do you know that you are ready to support a workload?
  • Continuous improvement culture
  • Share understanding of the value to the business
  • Ensure personnel capability
  • Documented accessible governance and guidance
  • Use checklists
  • Use playbooks
  • Practice recovery
• OPS 4: What factors drive your understanding of operational health?
  • Define expected business and customer outcomes
  • Identify success metrics
  • Identify workload metrics
  • Identify ops metrics
  • Established baselines
  • Collect and analyze metrics
  • Validate indights
  • Business-level view of ops
• OPS 5: How do you manage operational events?
  • Determine priority of operational events based on business impact
  • Processes for event, incident, and problem management
  • Process per alert
  • ID decision makers
  • Define escalation paths
  • Push notifications
  • Communicate status through dashboards
  • Process for root cause analysis
• OPS 6: How do you evolve operations?
  • frequent small improvements; providing safe environments and time to experiment, develop, and test improvements; and environments in which learning from failures is encouraged
  • Process for Continuous Improvement
  • Define drivers for improvement
  • Implement feedback loops
  • Document and share lessons learned
  • Perform ops metrics reviews

Key Services

• AWS CloudFormation = essential to Ops Excellence
• Amazon QuickSight is a business analytics service that makes it easy to build visualizations, perform ad-hoc analysis, and quickly get insights from your data.
• Amazon Athena is a serverless interactive query service that makes it easy to analyze data in Amazon S3
• Amazon S3 can be used for collection and archival retention of logs
• Amazon CloudWatch is used for the collection of logs and metrics and the creation of dashboards.

2) SEC: Security

Design principles for Security

• Implement a strong identity foundation
  • principle of least privilege
  • enforce separation of duties
  • centralize privilege mgmt
  • eliminate reliance on long-term credentials
• Enable traceability
  • monitor, alert and audit actions and changes in real time
  • integrate logs and metrics with systems to auto respond
• Apply security at all layers
  • defense-in-depth
  • apply to all layers (edge, VPC, subnet, load balancer, every instance, OS, apps)
• Automate security best practices
• Protect data in transit
• Protect data at rest
• Keep people away from data
• Prepare for security events

Best Practices

• SEC 1: How do you manage credentials for your workload?
  • Enforce use of MFA, PW reqs
  • Rotate creds regularly
  • Audit creds periodically
  • Use centralized identity provider
• SEC 2: How do you control human access to services?
  • Creds are not shared
  • User life-cycle managed
  • Min privileges
  • Clearly defined access req
  • Grant access via roles or federation
• SEC 3: How do you control programmatic access to services?
  • Creds are not shared
  • Dynamic auth
  • Min privileges
  • Clearly defined access req
• SEC 4: How are you aware of security events in your workload?
  • Logging enables where avail
  • Analyze AWS CloudTrail
  • Analyze logs centrally
  • Monitoring and alerting for key metrics and events
  • AWS marketplace or APN partner solution enabled
• SEC 5: How do you protect your networks?
  • Controlling traffic in VPC
  • Controlling traffic at the boundary or edge
  • Control traffic using SGs, ACLs, subnets
  • AWS marketplace or APN partner solution enabled
• SEC 6: How do you stay up to date with AWS security features and industry security threats?
  • Evaluate new sec services and features
  • Using sec services and features
• SEC 7: How do you protect your compute resources?
  • Hardening default config
  • Check file integrity
  • Intrusion detection enables
  • AWS marketplace or APN partner solution enabled
  • Config mgmt tool
  • Patch and scan for vulnerabilities
• SEC 8: How do you classify your data?
  • Use a data classification schema
  • Apply the classification
• SEC 9: How do you manage data protection mechanisms?
  • Use a secure key mgmt service
  • Use service level controls
  • Use client side key mgmt
  • AWS marketplace or APN partner solution
• SEC 10: How do you protect your data at rest?
  • Encrypting
• SEC 11: How do you protect your data in transit?
  • Encrypting (TLS communications)
• SEC 12: How do you prepare to respond to an incident?
  • Pre-provisioned access
  • Pre-deployed tools
  • Run game days

Key AWS Services

1. Identity and Access Management

• AWS IAM

2. Detective Control

• AWS CloudTrail - records AWS API calls
• AWS Config - inventory of AWS resources and config
• AWS CloudWatch - monitoring and can trigger AWS CloudWatch Events

3. Infrastructure Protection

• Amazon VPC enables launching into virtual network
• AWS Cloudfront is a global CDN
• securely delivers data, videos, applications, and APIs
• integrates with AWS Shield for DDos
• AWS WAF deploys onto CloudFront or App Load Balancer

4. Data Protection

• As an AWS customer you maintain full control over your data.
• Encrypt your data and manage keys, including regular key rotation.
• AWS ELB (Elastic Load Balancer)
• AWS EBS (Elastic Block Store)
• AWS S3 (Simple Storage Service)
• AWS RDS (Relational Database Service)
• Amazon Macie - automatically discovers, classifies and protects sensitive data,
• AWS KMS (Key Management Service) - makes it easy for you to create and control keys

5. Incident Response

• AWS CloudFormation - create a trusted env or clean room for investigations
• AWS CloudWatch - can trigger responses (including AWS Lambda)

3) REL: Reliability

Best Practices - Foundations, Change management, Failure management

• REL 1: How are you managing AWS service limits for your accounts?
  • Active monitoring and managing limits
  • Implemen automated monitoring and mgmt or limits
  • Be aware of fixed service limits
  • Ensure sufficient gap between limit and max use to accommodate for failover
  • Services limits managed across all relevant accts and regions
• REL 2: How do you plan your network topology on AWS?
  • Connectivity back to data center is not needed?
  • Highly avail connectivity between AWS and on-prem env implemented?
  • Highly avail network connectivity for users of workload implemented?
  • Non-overlapping private IP address ranges in VPCs?
  • IP subnet alloc accounts for expansion and avail?
• REL 3: How does your system adapt to changes in demand?
  • Workload scales automatically
  • Workload is load tested
• REL 4: How do you monitor AWS resources?
  • Monitor the workload in all tiers
  • Notifications are sent based on the monitoring
  • Automated responses are performed for events
  • Reviews are conducted regularly
• REL 5: How do you implement change?
  • Changes are deployed with automation
• REL 6: How do you back up data?
  • Data is backed up manually
  • Data is backed up using automated processes
  • Periodic recovery of the data is done to verify backup integrity and proc
  • Backups are secured and encrypted
• REL 7: How does your system withstand component failures?
  • Monitoring is done at all layers of the workload to detect failures
  • Deployed to multiple AZs and Regions if required
  • Loosely coupled dependencies
  • Implement graceful degradation
  • Auto healing implemented on all layers
  • Notifications sent upon events impacting availability
• REL 8: How do you test resilience?
  • Use a playbook
  • Inject failures to test
  • Schedule game days
  • Conduct RCAs
• REL 9: How do you plan for disaster recovery?

4) PERF: Performance Efficiency

Design Principles for Performance Efficiency

• Democratize advanced technologies
• Go global in minutes
• Use serverless architectures
• Experiment more often
• Mechanical sympathy

Best Practices & Key AWS Services for Performance Efficiency

• PERF 1: How do you select the best performing architecture?
  • Benchmarking
  • Load test
• PERF 2: How do you select your compute solution?
  • Consider options
  • Consider instance config options (family, instance size and feature)
  • Consider container config options (memory, CPU, tenancy config)
  • Consider function config options (memory, runtime, state)
  • Use elasticity to meet demand changes:
    • AWS Auto Scaling
    • AWS ECS
    • AWS Lambda
• PERF 3: How do you select your storage solution?
  • Consider characteristics: share, size, cache, access, latency, throughput, persistence
  • Consider config options (PIOPS, SSD, S3 Transfer Accel)
  • Consider access patterns (striping, key distro, partitioning)
  • AWS storage options:
    • AWS EBS,
    • AWS S3
• PERF 4: How do you select your database solution?
  • Consider characteristics: avail, consistency, tolerance, latency, durability, scalability, query capacility rational, NoSQL, warehouse, in-memory
  • Consider config options (memory, cache)
  • Consider access patterns (index, key distro, partition, scaling)
  • Consider other approaches (queryable data, search indexes, data warehouses, Big Data)
  • AWS Database solutions:
    • AWS RDS
    • AWS DynamoDB
• PERF 5: How do you configure your networking solution?
  • Consider location (Region, AZ, placement group, edge loc) = REDUCE LATENCY
  • Consider service features:
    • AWS EC2 instance network capability,
    • Amazon EBS-optimized,
    • AWS CloudFront
  • Consider networking features:
    • AWS Route53 latency-based routing
    • AWS VPC endpoints
    • AWS Direct Connect
• PERF 6: How do you evolve your workload to take advantage of new releases?
  • Use process for evaluation
  • AWS news and updated:
    • AWS Blog
• PERF 7: How do you monitor your resources to ensure they are performing as expected?
  • Monitor, Alarm-based notifications, Trigger based actions
  • AWS monitoring solutions
    • AWS CloudWatch
• PERF 8: How do you use tradeoffs to improve performance?
  • Use services
    • ElastiCache
    • CloudFront
    • Snowball
  • Use patterns - caching, read replicas, sharding, compression, buffering
  • Recovery objectives are defined (RTO and RPO)
  • Recovery strategy is defined
  • Configuration drift is managed (AMIs and the system config up-to-date)
  • Test and validate DR implementation
  • Recovery is automated

5) Cost Optimization

Pillars for cost optimization & Key Services

1. Cost-Effective Resources
2. Matching supply and demand
3. Expenditure Awareness
4. Optimizing Over Time

Best Practices for Cost Optimization

• COST 1: How do you evaluate cost when you select AWS services?
  • Select service for cost reduction
  • Optimize for license costs
  • Optimize using serverless and container-base approach
  • Optimize using appropriate storage solutions
  • EBS cold storage, S3 Std-Infrequent, Glacier
  • Optimize using appropriate databases
  • Amazon RDS (Aurora, PostgreSQL, MySQL, SQL Server, Oracle Database)
  • Amazon DynamoDB (or other key-value stores, NoSQL alternatives)
  • Optimize using other app-level services
    • AWS SQS - (Simple Queue Service)
    • AWS SNS - (Simple Notification Service)
    • AWS SES - (Simple Email Service)
• COST 2: How do you meet cost targets with resource type and size choices?
  • Metrics-driven resource sizing
• COST 3: How do you use pricing models to reduce cost?
  • Reserved capacity and commit deals
  • Spot instances
  • Region cost
• COST 4: How do you plan for data transfer charges?
  • Optimize, WAN acceleration, Multi-AW, Regions selection
  • Use a Content Delivery Network (CDN)
    • AWS Cloudfront
  • AWS Direct Connect
• COST 5: How do you match supply of resources with customer demand?
  • Demand-based approach
  • Buffer-based approach
  • Time-base approach
• COST 6: How do you monitor usage and cost?
  • Tag all resources!
  • Use billing and cost management tools
  • Notifications
  • Business outcome alloc
• COST 7: How do you govern AWS usage?
  • Establish groups and roles (who can spin up instances)
  • Track project lifecycle
• COST 8: How do you decommission resources?
  • Automate decommission
  • Defined process
• COST 9: How do you evaluate new services?
  • Schedule review (Sol Arch, acct team, cost benefit)
  • Establish a cost optimization function / team
  • Review and analyze workload

Disaster Recovery Whitepaper (2014)

• Recovery Time Objective (RTO) - the time it takes after a disruption to restore a business process to its service level and
• Recovery Point Objective (RPO) - acceptable amount of data loss measured in time before the disaster occurs

Techniques

• Backup & Restore – Data is backed up and restored, within nothing running
• Pilot light – Only minimal critical service like RDS is running and rest of the services can be recreated and scaled during recovery
• Warm Standby – Fully functional site with minimal configuration is available and can be scaled during recovery
• Multi-Site – Fully functional site with identical configuration is available and processes the load

AWS Services for recovery

• Region and AZ to launch services across multiple facilities
• EC2 instances with the ability to scale and launch across AZs
• EBS with Snapshot to recreate volumes in different AZ or region
• AMI to quickly launch preconfigured EC2 instances
• ELB and Auto Scaling to scale and launch instances across AZs
• VPC to create private, isolated section
• Elastic IP address as static IP address
• ENI with pre allocated Mac Address
• Route 53 is highly available and scalable DNS service to distribute traffic across EC2 instances and ELB in different AZs and regions
• Direct Connect for speed data transfer (takes time to setup and expensive then VPN)
• S3 and Glacier (with RTO of 3-5 hours) provides durable storage
• RDS snapshots and Multi AZ support and Read Replicas across regions
• DynamoDB with cross region replication
• Redshift snapshots to recreate the cluster
• Storage Gateway to backup the data in AWS
• Import/Export to move large amount of data to AWS (if internet speed is the bottleneck)
• CloudFormation, Elastic Beanstalk and Opsworks as orchestration tools for automation and recreate the infrastructure

Cheat Sheet - AWS Services Summary

Original Source: http://jayendrapatil.com/aws-certification-exam-cheat-sheet/

AWS Organizations

• offers policy-based management for multiple AWS accounts
• allows creation of groups of accounts and then apply policies to those groups
• enables you to centrally manage policies across multiple accounts, without requiring custom scripts and manual processes.
• helps simplify the billing for multiple accounts by enabling the setup of a single payment method for all the accounts in the organization through consolidated billing

AWS Global Infrastructure (AWS Region, AZs, Edge locations)

• Each region is a separate geographic area, completely independent, isolated from the other regions & helps achieve the greatest possible fault tolerance and stability
  • Communication between regions is across the public Internet
  • Each region has multiple Availability Zones (UPDATE: Osaka-Local has one region has 1 AZ)
• Each AZ is physically isolated, geographically separated from each other and designed as an independent failure zone AZs are connected with low-latency private links (not public internet)
• Edge locations are locations maintained by AWS through a worldwide network of data centers for the distribution of content to reduce latency. (Not necessarily in the AZ's)
• AWS has announced plans to expand with 12 new AZs in four new geographic Regions: Bahrain, Cape Town, Hong Kong SAR, and Milan. (As of Jan 2019)

AWS Services Region, AZ, Subnet VPC limitations

• Services like IAM (user, role, group, SSL certificate), Route 53, STS are Global and available across regions
• All other AWS services are limited to Region or within Region and do not exclusively copy data across regions unless configured
• AMIs are limited to regions and need to be copied over to other region
• EBS volumes are limited to the AZ, and can be migrated by creating snapshots and copying them to another region
• Reserved instances can be migrated to other AZ
• RDS instances are limited to the region and can be recreated in a different region by either using snapshots or promoting a Read Replica
• Placement groups are limited to the AZ
• Cluster Placement groups are limited to single AZs
• Spread Placement groups can span across multiple Availability Zones
• S3 data is replicated within the region to AZs and can be move to another region using cross region replication
  • Cross region replication (CRR) use and requirements
• DynamoDB maintains data within the region and can be replicated to another region using DynamoDB cross region replication (using DynamoDB streams) or Data Pipeline using EMR (old method)
• Redshift Cluster span within an AZ only, and can be created in other AZ using snapshots

AWS Consolidated Billing

• One bill for multiple AWS accouns
• Paying account with multiple linked accounts
• Payer account is independent and should be only used for billing purpose
• Paying account cannot access resources of other accounts unless given exclusively access through Cross Account roles
• All linked accounts are independent and soft limit of 20
• Allows unused Reserved Instances to be applied across the group
• Free tier is not applicable across the accounts

AWS Multiple Account Billing Strategy

• Use a group alias rather than an individual email address as the account email address to ensure continuity of communication
• Implement AWS tagging standards across your accounts

Tags & Resource Groups

• Resource Group is a collection of resources that share one or more tags
  • AWS Resource Groups API
• Tags are key and value pairs that act as metadata for organizing your AWS resources
• Tags can be inherited when created resources created from Auto Scaling, Cloud Formation, Elastic Beanstalk etc
• Tags and Resource Groups can be used for:
  • Cost allocation to categorize and track the AWS costs
  • Conditional Access Control policy to define resource permission based on tags
  • Applying updates or security patches.
  • Upgrading applications.
  • Opening or closing ports to network traffic.
  • Collecting specific log and monitoring data from your fleet of instances.

IDS/IPS

• Promiscuous mode is not allowed. AWS and Hypervisor will not deliver any traffic to instances this is not specifically addressed to the instance

IDS/IPS: Strategies

• Host Based Firewall
  • Forward Deployed IDS where the IDS itself is installed on the instances – Traffic Replication where IDS agents installed on instances which send/duplicate the data to a centralized IDS system
• In-Line Firewall – Inbound IDS/IPS Tier (like a WAF configuration) which identifies and drops suspect packets

IDS/IPS: DDOS Mitigation

• Minimize the Attack surface
  • Use AWS ELB, AWS CloudFront, and AWS Route 53 to distribute load
  • maintain resources in private subnets and use Bastion servers
• Scale to absorb the attack
  • Scaling helps buy time to analyze and respond to an attack
  • ELB auto scaling help handle increased load to absorb attacks
  • CloudFront and Route 53 inherently scales as per the demand
• Safeguard exposed resources
  • use Route 53 for aliases to hide source IPs and Private DNS
  • use CloudFront geo restriction and Origin Access Identity
  • use WAF as part of the infrastructure
• Learn normal behavior (IDS/WAF)
  • analyze and benchmark to define rules on normal behavior
  • use CloudWatch
• Create an IR plan for attacks

Cheat Sheet - Security & Identity Services

Security & Identity Services: IAM

• securely control access to AWS services and resources
• helps create and manage user identities and grant permissions for those users to access AWS resources
• helps create groups for multiple users with similar permissions
• not appropriate for application authentication
• is Global and does not need to be migrated to a different region
• helps define Policies,
  • in JSON format
  • all permissions are implicitly denied by default
  • most restrictive policy wins

Security & Identity Services: IAM Role

• helps grants and delegate access to users and services without the need of creating permanent credentials
• IAM users or AWS services can assume a role to obtain temporary security credentials that can be used to make AWS API calls
• needs Trust policy to define who and Permission policy to define what the user or service can access
• used with AWS STS (Security Token Service), a lightweight web service that provides temporary, limited privilege credentials for IAM users or for authenticated federated users

IAM role scenarios

• Service access for e.g. EC2 to access S3 or DynamoDB
• Cross Account access for users
  • with user within the same account
  • with user within an AWS account owned the same owner
  • with user from a Third Party AWS account with External ID for enhanced security
• Identity Providers & Federation
  • Web Identity Federation, where the user can be authenticated using external authentication Identity providers like Amazon, Google or any OpenId IdP using AssumeRoleWithWebIdentity
  • Identity Provider using SAML 2.0, where the user can be authenticated using on premises Active Directory, Open Ldap or any SAML 2.0 compliant IdP using AssumeRoleWithSAML
  • For other Identity Providers, use Identity Broker to authenticate and provide temporary Credentials using AssumeRole (recommended) or GetFederationToken

Security & Identity Services: IAM Best Practices

• Do not use Root account for anything other than billing
• Create Individual IAM users
• Use groups to assign permissions to IAM users
• Grant least privilege
• Use IAM roles for applications on EC2
• Delegate using roles instead of sharing credentials
• Rotate credentials regularly
• Use Policy conditions for increased granularity
• Use CloudTrail to keep a history of activity
• Enforce a strong IAM password policy for IAM users
• Remove all unused users and credentials

Security & Identity Services - CloudHSM

• provides secure cryptographic key storage to customers by making hardware security modules (HSMs)
• single tenant, dedicated physical device to securely generate, store, and manage cryptographic keys used for data encryption
• inside the VPC (not EC2-classic) & isolated from the rest of the network
• can use VPC peering to connect to CloudHSM from multiple VPCs
• integrated with Amazon Redshift and Amazon RDS for Oracle
• EBS volume encryption, S3 object encryption and key management can be done with CloudHSM w/ custom application scripting
• NOT fault tolerant and would need to build a cluster - if one fails all the keys are lost
• expensive, prefer AWS Key Management Service (KMS) if cost is a criteria

Cheat Sheet - Network Services

Network Services: AWS Directory Services

• Managed Microsoft Active Directory in the AWS Cloud
• gives applications in AWS access to Active Directory services
• different from SAML + AD - where the access is granted to AWS services through Temporary Credentials

AWS Directory Services: Benefits

• EASILY MIGRATE DIRECTORY-AWARE, ON-PREMISES WORKLOADS
• USE ACTUAL MICROSOFT ACTIVE DIRECTORY
• SHARE A SINGLE DIRECTORY FOR CLOUD WORKLOADS
• EASILY EXTEND EXISTING DOMAINS
• CENTRALLY MANAGE APPLICATION ACCESS AND DEVICES IN THE AWS CLOUD
• SIMPLIFY ADMINISTRATION WITH A MANAGED SERVICE

AWS Directory Services: Simple AD

• least expensive but does not support Microsoft AD advance features
• provides a Samba 4 Microsoft Active Directory compatible standalone directory service on AWS
• No single point of Authentication or Authorization, as a separate copy is maintained
• trust relationships cannot be setup between Simple AD and other Active Directory domains
• Don’t use it, if the requirement is to leverage access and control through centralized authentication service

AWS Directory Services: AD Connector

• acts as a hosted proxy service for cloud instances to connect to on-premises Active Directory
• enables consistent enforcement (between cloud and on-prem) of existing security policies, such as:
  • password expiration
  • password history
  • account lockouts
• needs VPN connectivity (or Direct Connect)
• enable MFA by integrating with existing RADIUS-based MFA solutions
• does not cache data - might lead to latency

AWS Directory Services: Read-only Domain Controllers (RODCs)

• works out as a Read-only Active Directory
• holds a copy of the Active Directory Domain Service (AD DS) database and respond to authentication requests
• cannot be written to and are typically deployed in locations where physical security cannot be guaranteed
• helps maintain a single point to authentication & authorization controls, however needs to be synced

AWS Directory Services: Writable Domain Controllers

• are expensive to setup
• operate in a multi-master model
• changes can be made on any writable server in the forest, and those changes are replicated to servers throughout the entire forest

Network Services: AWS WAF (Web Application Firewall)

• helps monitor the HTTP/HTTPS requests forwarded to CloudFront and allows controlling access to the content.
• helps define Web ACLs, which is a combination of Rules, which is a combinations of Conditions and Action to block or allow

Third Party WAF

• act as filters that apply a set of rules to web traffic to cover exploits like XSS and SQL injection and also help build resiliency against DDoS by mitigating HTTP GET or POST floods
• provides a lot of features like OWASP Top 10, HTTP rate limiting, Whitelist or blacklist, inspect and identify requests with abnormal patterns, CAPTCHA etc
• a WAF sandwich pattern can be implemented where an autoscaled WAF sits between the Internet and Internal Load Balancer

Network Services: VPC (Virtual Private Cloud)

• helps define a logically isolated dedicated virtual network within the AWS
• provides control of IP addressing using CIDR block from a minimum of /28 to maximum of /16 block size

Network Services: VPC Components

• Internet gateway (IGW) provides access to the Internet
• Virtual gateway (VGW) provides access to on-premises data center through VPN and Direct Connect connections
• VPC can have only one IGW and VGW
• Route tables determine where network traffic from subnet is directed
• Ability to create subnet with VPC CIDR block
• Network Address Translation (NAT) server provides outbound Internet access for EC2 instances in private subnets
• Elastic IP addresses are static, persistent public IP addresses
• Instances launched in the VPC always have a Private IP and can have a Public or a Elastic IP address associated
• Security Groups and NACLs help define security
• Flow logs capture information about IP traffic going to and from network interfaces in your VPC

Network Services: VPC NAT (Network Address Translation)

• allows internet access to instances in private subnet
• performs the function of both address translation and port address translation (PAT)
• needs source/destination check flag to be disabled as it is not actual destination of the traffic
• NAT gateway is a AWS managed NAT service that provides better availability, higher bandwidth, and requires less administrative effort

Network Services: VPC Route Tables

• defines rules, termed as routes, which determine where network traffic from the subnet would be routed
• Each VPC has a Main Route table, and can have multiple custom route tables created
• Every route table contains a local route that enables communication within a VPC which cannot be modified or deleted
• Route priority is decided by matching the most specific route in the route table that matches the traffic

Network Services: VPC Subnets

• map to AZs and do not span across AZs
• have a CIDR range that is a portion of the whole VPC.
• CIDR ranges cannot overlap between subnets within the VPC.
• AWS reserves 5 IP addresses in each subnet – first 4 and last one
• Each subnet is associated with a route table which define its behavior
• Public subnets – inbound/outbound Internet connectivity via IGW
• Private subnets – outbound Internet connectivity via an NAT or VGW
• Protected subnets – no outbound connectivity and used for regulated workloads

Network Services: VPC ENI (Elastic Network Interface)

• default ENI, eth0, is attached to an instance (which cannot be detached) with one or more secondary detachable ENIs (eth1-ethn)
• has primary private, one or more secondary private, public, Elastic IP address, security groups, MAC address and source/destination check flag attributes associated
• An ENI in one subnet can be attached to an instance in the same or another subnet, in the same AZ and the same VPC
• Security group membership of an ENI can be changed
• with pre allocated Mac Address can be used for applications with special licensing requirements

VPC Security Groups vs Network Access Control Lists

Security Groups	Network ACLs
Stateful	Statless
Instance level	Subnet level
Only allows ALLOW rules	Both Allow and Deny rules
Evaluates as a whole	Evaluated in defined order

Network Services: VPC EIP (Elastic IPs)

• is a static IP address designed for dynamic cloud computing.
• is associated with AWS account, and not a particular instance
• can be remapped from one instance to an other instance
• is charged for non usage, if not linked for any instance or instance associated is in stopped state
• charged if more than one assigned to an instance

Network Services: VPC Peering

• allows routing of traffic between the peer VPCs using private IP addresses and no IGW or VGW required
• No single point of failure and bandwidth bottlenecks
• VPC peering across regions is now supported (as of 2017-11)
• IP space or CIDR blocks cannot overlap
• cannot be transitive, one-to-one relationship between two VPC
• Only one between any two VPCs and have to be explicitly peered
• Private DNS values cannot be resolved
• Security groups from peered VPC cannot be referred for ingress and egress rules in security group, use CIDR block instead

Network Services: VPC Endpoints

• enables creation of a private connection between VPC and another AWS service using its private IP address
• does not require a public IP address, access over the Internet, NAT device, a VPN connection or AWS Direct Connect
• traffic between VPC & AWS service does not leave the Amazon network
• interface endpoint is an elastic network interface with a private IP address that serves as an entry point for traffic destined to a supported service
• gateway endpoint is a gateway that is a target for a specified route in your route table, used for traffic destined to a supported AWS service

Network Services: Direct Connect

• network service that provides an alternative to using Internet to utilize AWS services by using private dedicated network connection
• provides Virtual Interfaces
• Private VIF to access instances within an VPC via VGW
• Public VIF to access non VPC services
• requires time to setup probably months, and should not be considered as an option if turnaround time is less
• does not provide redundancy, use either second direct connection or IPSec VPN connection
• Virtual Private Gateway is on the AWS side and Customer Gateway is on the Customer side
• route propagation is enabled on VGW and not on CGW

Network Services: VPN

• provide secure IPSec connections from on-premise computers or services to AWS over the Internet
• is quick to setup, is cheap however it depends on the Internet speed

Direct Connect	VPN IPSec
Expensive to Setup and Takes time	Cheap & Immediate
Dedicated private connections	Internet
Reduced data transfer rate	Internet data transfer cost
Consistent performance	Internet inherent variability
Do not provide Redundancy	Provides Redundancy

Network Services: Route 53

• Highly available and scalable DNS & Domain Registration Service
• Reliable and cost-effective way to route end users to Internet applications
• Supports multi-region and backup architectures for High availability. ELB , limited to region, does not support multi region HA architecture
• supports private Intranet facing DNS service
• internal resource record sets only work for requests originating from within the VPC and currently cannot extend to on-premise
• Global propagation of any changes made to the DN records within ~ 1min
• Route 53 to create an alias resource record set that points to ELB, S3, CloudFront. An alias resource record set is an Route 53 extension to DNS. It’s similar to a CNAME resource record set, but supports both for root domain – zone apex e.g. example.com, and for subdomains for e.g. www.example.com.
• CNAME resource record sets can be created only for subdomains and cannot be mapped to the zone apex record
• Weighted, Latency and Geolocation can be used for Active-Active while Failover routing can be used for Active-Passive multi region architecture

Network Services: Route 53 Routing Policy

• Simple routing – simple round robin policy
• Weighted round robin – assign weights to resource records sets to specify the proportion for e.g. 80%:20%
• Latency based routing – helps improve global applications as request are sent to server from the location with minimal latency, is based on the latency and cannot guarantee users from the same geographic will be served from the same location for any compliance reasons
• Geolocation routing – Specify geographic locations by continent, country, state limited to US, is based on IP accuracy
• Failover routing – failover to a backup site if the primary site fails and becomes unreachable

Cheat Sheet - Compute Services

Compute Services: EC2

• provides scalable computing capacity
• Virtualization for EC2 is run using the Xen Hypervisor software

Compute Services: EC2 Features

• Virtual computing environments, known as EC2 instances
• Preconfigured templates for EC2 instances, known as Amazon Machine Images (AMIs), that package the bits needed for the server (including the operating system and additional software)
• Various configurations of CPU, memory, storage, and networking capacity for your instances, known as Instance types
• Secure login information for your instances using key pairs (public-private keys where private is kept by user)
• Storage volumes for temporary data that’s deleted when you stop or terminate your instance, known as Instance store volumes
• Persistent storage volumes for data using Elastic Block Store (EBS)
• Multiple physical locations for your resources, such as instances and EBS volumes, known as Regions and Availability Zones
• A firewall to specify the protocols, ports, and source IP ranges that can reach your instances using Security Groups Static IP addresses (Elastic IP addresses)
• Metadata, known as tags, can be created and assigned to EC2 resources
• Virtual networks that are logically isolated from the rest of the AWS cloud, and can optionally connect to on premises network, known as Virtual private clouds (VPCs)

Compute Services: EC2 AMIs (Amazon Machine Images)

• template from which EC2 instances can be launched quickly
• does NOT span across across regions, and needs to be copied
• can be shared with other specific AWS accounts or made public

Compute Services: EC2 Purchasing Options

• Dedicated Instances - tenancy option which enables instances to run in VPC on hardware that’s isolated, dedicated to a single customer
• Light, Medium, and Heavy Utilization Reserved Instances are no longer available for purchase and were part of the Previous Generation AWS EC2 purchasing model

On-Demand Instances

• pay for instances and compute capacity that you use by the hour
• with no long-term commitments or up-front payments

Reserved Instances

1. Applications have steady state or predictable usage
2. Applications that require reserved capacity
3. Users able to make upfront payments to reduce their total computing cost even further - Buy when you know what you will need for the next 12+ months

• provides lower hourly running costs by providing a billing discount
• capacity reservation that is applied to instances
• suited if consistent, heavy, predictable usage
• provides benefits with Consolidate Billing
• can be modified to switch Availability Zones or the instance size within the same instance type, given the instance size footprint (Normalization factor) remains the same
• pay for the entire term regardless of the usage, so if the question targets cost effective solution and answer mentions reserved instances are purchased & unused, it can be ignored

Spot Instances

• cost-effective choice but does NOT guarantee availability
• applications flexible in the timing when they can run and also able to handle interruption by storing the state externally
• AWS will give a two minute warning if the instance is to be terminated to save any unsaved work

Compute Services: EC2 Enhanced Networking

• results in higher bandwidth, higher packet per second (PPS) performance, lower latency, consistency, scalability and lower jitter
• supported using Single Root I/O Virtualization (SR-IOV) only on supported instance types
• is supported only with an VPC (not EC2 Classic), HVM virtualization type and available by default on Amazon AMI but can be installed on other AMIs as well

Compute Services: EC2 Placement Group

1. A placement group is a logical grouping of instances within a single availability zone
2. Using placement groups enables applications to participate in a low latency, 10 Gbps network
3. Placement Groups are recommended for applications that benefit from low network latency, high network throughput, or both

• provide low latency, High Performance Computing via 10Gbps network
• is a logical grouping on instances within a Single AZ
• don’t span availability zones, can span multiple subnets but subnets must be in the same AZ
• NOTE – Spread Placement Groups can span multiple AZs.
• can span across peered VPCs for the same Availability Zones
• existing instances cannot be moved into an existing placement group
• for capacity errors, stop and start the instances in the placement group
• use homogenous instance types which support enhanced networking and launch all the instances at once

Compute Services: Load Balancing and Auto Scaling

• Auto Scaling & ELB can be used for High Availability and Redundancy by spanning Auto Scaling groups across multiple AZs within a region and then setting up ELB to distribute incoming traffic across those AZs
• With Auto Scaling use ELB health check with the instances to ensure that traffic is routed only to the healthy instances

Compute Services: AWS ELB (Elastic Load Balancer)

• Managed load balancing service and scales automatically
• distributes incoming application traffic across multiple EC2 instances
• is distributed system that is fault tolerant and actively monitored by AWS scales it as per the demand
• are engineered to not be a single point of failure
• need to Pre Warm ELB if the demand is expected to shoot especially during load testing
• supports routing traffic to instances in multiple AZs in the same region
• performs Health Checks to route traffic only to the healthy instances
• support Listeners with HTTP, HTTPS, SSL, TCP protocols
• has an associated IPv4 and dual stack DNS name
• can offload the work of encryption and decryption (SSL termination) so that the EC2 instances can focus on their main work
• supports Cross Zone load balancing to help route traffic evenly across all EC2 instances regardless of the AZs they reside in
• to help identify the IP address of a client
  • supports Proxy Protocol header for TCP/SSL connections
  • supports X-Forward headers for HTTP/HTTPS connections
• supports Stick Sessions (session affinity) to bind a user’s session to a specific application instance,
  • it is not fault tolerant, if an instance is lost the information is lost
  • requires HTTP/HTTPS listener and does not work with TCP
  • requires SSL termination on ELB as it users the headers
• supports Connection draining to help complete the in-flight requests in case an instance is deregistered
• For High Availability - recommended to attach one subnet per AZ for at least two AZs, even if the instances are in a single subnet.
• cannot assign an Elastic IP address to an ELB
• IPv4 & IPv6 support however VPC does not support IPv6. VPC now supports IPV6.
• HTTPS listener does not support Client Side Certificate
• for SSL termination at backend instances or support for Client Side Certificate use TCP for connections from the client to the ELB, use the SSL protocol for connections from the ELB to the back-end application, and deploy certificates on the back-end instances handling requests
• supports a single SSL certificate, so for multiple SSL certificate multiple ELBs need to be created

Compute Services: Auto Scaling

• ensures correct number of EC2 instances are always running to handle the load by scaling up or down automatically as demand changes
• cannot span multiple regions.
• attempts to distribute instances evenly between the AZs that are enabled for the Auto Scaling group
• performs checks either using EC2 status checks or can use ELB health checks to determine the health of an instance and terminates the instance if unhealthy, to launch a new instance
• can be scaled using manual scaling, scheduled scaling or demand based scaling
• cooldown period helps ensure instances are not launched or terminated before the previous scaling activity takes effect to allow the newly launched instances to start handling traffic and reduce load

Compute Services: EC2 Auto Scaling Groups

• EC2 instances are organized into groups so that they can be treated as a logical unit for the purposes of scaling and management
• you can specify its minimum, maximum, and, desired number of EC2 instances
• groups uses a launch configuration as a template for its EC2 instances.
• When you create a launch configuration, you can specify information such as the AMI ID, instance type, key pair, security groups, and block device mapping for your instance

Compute Services: EC2 Load Balancer (Classic Load Balancing)

• Internet-facing load balancer
  • has a publicly resolvable DNS name, so it can route requests from clients over the Internet to the EC2 instances that are registered with the load balancer.
  • created INSIDE a PUBLIC SUBNET
  • Configure health checks, and Register back-end instances
  • Configure a listener by specifying a protocol and a port for front-end (client to load balancer) connections, and a protocol and a port for back-end (load balancer to back-end instances) connections
• Internal load balancer
  • has only private IP addresses.
  • The DNS name of an internal load balancer is publicly resolvable to the private IP addresses of the nodes
  • When an internal load balancer is created, it receives a public DNS name with the following form: internal-name-123456789.region.elb.amazonaws.com

Compute Services: AWS EBS (Elastic Block Store)

• is virtual network attached block storage
• volumes CANNOT be shared with multiple EC2 instances, use EFS instead
• persists and is independent of EC2 lifecycle
• multiple volumes can be attached to a single EC2 instance
• can be detached & attached to another EC2 instance in that same AZ only
• volumes are created in an specific AZ and CANNOT span across AZs
• snapshots CANNOT span across regions
• for making volume available to different AZ, create a snapshot of the volume and restore it to a new volume in any AZ within the region
• for making the volume available to different Region, the snapshot of the volume can be copied to a different region and restored as a volume
• provides high durability and are redundant in an AZ, as the data is automatically replicated within that AZ to prevent data loss due to any single hardware component failure
• PIOPS is designed to run transactions applications that require high and consistent IO for e.g. Relation database, NoSQL etc

Cheat Sheet - Storage Services

Storage Services: S3

• Key-value based object storage with unlimited storage, unlimited objects up to 5 TB for the internet
• is an Object level storage (not a Block level storage) and cannot be used to host OS or dynamic websites
• provides durability by redundantly storing objects on multiple facilities within a region
• support SSL encryption of data in transit and data encryption at rest
• regularly verifies the integrity of data using checksums and provides auto healing capability
• integrates with CloudTrail, CloudWatch and SNS for event notifications

S3 resources

• consists of bucket and objects stored in the bucket which can be retrieved via a unique, developer-assigned key
• bucket names are globally unique
• data model is a flat structure with no hierarchies or folders
• Logical hierarchy can be inferred using the keyname prefix e.g. Folder1/Object1

S3 Bucket & Object Operations

• allows retrieval of 1000 objects and provides pagination support and is NOT suited for list or prefix queries with large number of objects
• with a single put operations, 5GB size object can be uploaded
• use Multipart upload to upload large objects up to 5 TB and is recommended for object size of over 100MB for fault tolerant uploads
• support Range HTTP Header to retrieve partial objects for fault tolerant downloads where the network connectivity is poor
• Pre-Signed URLs can also be used shared for uploading/downloading objects for limited time without requiring AWS security credentials
• allows deletion of a single object or multiple objects (max 1000) in a single call

S3 Multipart Uploads allows

• parallel uploads with improved throughput and bandwidth utilization
• fault tolerance and quick recovery from network issues
• ability to pause and resume uploads
• begin an upload before the final object size is known

S3 Versioning

• allows preserve, retrieve, and restore every version of every object
• protects individual files but does NOT protect from Bucket deletion

S3 Storage tiers

	Standard	Standard IA	Reduced Redundancy	Glacier
Durability	99.999999999%	99.999999999%	99.99%	99.999999999%
Availability	99.99%	99.9%	99.99%

• Standard
  • default storage class
  • Low latency and high throughput performance
  • designed to sustain the loss of data in a two facilities
• Standard IA
  • optimized for long-lived and less frequently accessed data
  • designed to sustain the loss of data in a two facilities
  • suitable for objects greater than 128 KB kept for at least 30 days
• Reduced Redundancy Storage
  • designed for noncritical, reproducible data stored at lower levels of redundancy than Standard
  • reduces storage costs
  • designed to sustain the loss of data in a single facility
• Glacier
  • suitable for archiving data where data access is infrequent and retrieval time of several (3-5) hours is acceptable

S3 Lifecycle Management Policies

• transition to move objects to different storage classes and Glacier
• expiration to remove objects

S3 Data Consistency Model

• provide read-after-write consistency for PUTS of new objects and eventual consistency for overwrite PUTS and DELETES
• for new objects, synchronously stores data across multiple facilitiesbefore returning success
• updates to a single key are atomic

S3 Security

• IAM policies – grant users within your own AWS account permission to access S3 resources
• Bucket and Object ACL – grant other AWS accounts (not specific users) access to S3 resources
• Bucket policies – allows to add or deny permissions across some or all of the objects within a single bucket

S3 Best Practices

• use random hash prefix for keys and ensure a random access pattern, as S3 stores object lexicographically randomness helps distribute the contents across multiple partitions for better performance
• use parallel threads and Multipart upload for faster writes
• use parallel threads and Range Header GET for faster reads
• for list operations with large number of objects, its better to build a secondary index in DynamoDB
• use Versioning to protect from unintended overwrites and deletions, but this does not protect against bucket deletion
• use VPC S3 Endpoints with VPC to transfer data using Amazon internet network

Storage Services: AWS Glacier

• suitable for archiving data, where data access is infrequent and a retrieval time of several hours (3 to 5 hours) is acceptable (Not true anymore with enhancements from AWS)
• provides a high durability by storing archive in multiple facilities and multiple devices at a very low cost storage
• performs regular, systematic data integrity checks and is built to be automatically self healing
• aggregate files into bigger files before sending them to Glacier and use range retrievals to retrieve partial file and reduce costs
• improve speed and reliability with multipart upload
• automatically encrypts the data using AES-256
• upload or download data to Glacier via SSL encrypted endpoints

Storage Services: AWS CloudFront

• provides low latency and high data transfer speeds for distribution of static, dynamic web or streaming content to web users
• delivers the content through a worldwide network of data centers called Edge Locations
• keeps persistent connections with the origin servers so that the files can be fetched from the origin servers as quickly as possible.
• dramatically reduces the number of network hops that users’ requests must pass through
• supports multiple origin server options, like AWS hosted service for e.g. S3, EC2, ELB or an on premise server, which stores the original, definitive version of the objects
• single distribution can have multiple origins and Path pattern in a cache behavior determines which requests are routed to the origin
• supports Web Download distribution and RTMP Streaming distribution
  • Web distribution supports static, dynamic web content, on demand using progressive download & HLS and live streaming video content
  • RTMP supports streaming of media files using Adobe Media Server and the Adobe Real-Time Messaging Protocol (RTMP) ONLY
• supports HTTPS using either
  • dedicated IP address, which is expensive as dedicated IP address is assigned to each CloudFront edge location
  • Server Name Indication (SNI), which is free but supported by modern browsers only with the domain name available in the request header
• For E2E HTTPS connection,
  • Viewers -> CloudFront needs either self signed certificate, or certificate issued by CA or ACM
  • CloudFront -> Origin needs certificate issued by ACM for ELB and by CA for other origins
• supports HTTP REQUEST METHODS: GET, HEAD, OPTIONS, PUT, POST, PATCH, DELETE to get object & object headers, add, update, and delete objects
  • only caches responses to GET and HEAD requests and, optionally, OPTIONS requests
  • does not cache responses to PUT, POST, PATCH, DELETE request methods and these requests are proxied back to the origin
• object removal from cache
  • would be removed upon expiry (TTL) from the cache, by default 24 hrs
  • can be invalidated explicitly, but has a cost associated, however might continue to see the old version until it expires from those caches
  • objects can be invalidated only for Web distribution
  • change object name, versioning, to serve different version
• supports adding or modifying custom headers before the request is sent to origin which can be used to
  • validate if user is accessing the content from CDN
  • identifying CDN from which the request was forwarded from, in case of multiple CloudFront distribution
  • for viewers not supporting CORS to return the Access-Control-Allow-Origin header for every request
• supports Partial GET requests using range header to download object in smaller units improving the efficiency of partial downloads and recovery from partially failed transfers
• supports compression to compress and serve compressed files when viewer requests include Accept-Encoding: gzip in the request header
• supports different price class to include all regions, to include only least expensive regions and other regions to exclude most expensive regions
• supports access logs which contain detailed information about every user request for both web and RTMP distribution

CloudFront Security

• Origin Access Identity (OAI) can be used to restrict the content from S3 origin to be accessible from CloudFront only
• supports Geo restriction (Geo-Blocking) to whitelist or blacklistcountries that can access the content
• Signed URLs
  • for RTMP distribution as signed cookies aren’t supported
  • to restrict access to individual files, for e.g., an installation download for your application.
  • users using a client, for e.g. a custom HTTP client, that doesn’t support cookies
• Signed Cookies
  • provide access to multiple restricted files, for e.g., video part files in HLS format or all of the files in the subscribers’ area of a website.
  • don’t want to change the current URLs
• integrates with AWS WAF, a web application firewall that helps protect web applications from attacks by allowing rules configured based on IP addresses, HTTP headers, and custom URI strings

Storage Services: AWS Import/Export

• accelerates moving large amounts of data into and out of AWS using portable storage devices for transport and transfers data directly using Amazon’s high speed internal network, bypassing the internet.
• suitable for use cases with
  • large datasets
  • low bandwidth connections
  • first time migration of data
• Importing data to several types of AWS storage, including EBS snapshots, S3 buckets, and Glacier vaults.
• Exporting data out from S3 only, with versioning enabled only the latest version is exported
• Import data can be encrypted (optional but recommended) while export is always encrypted using Truecrypt
• Amazon will wipe the device if specified, however it will not destroy the device

Cheat Sheet - Database Services

Amazon RDS (Relational Database Service) (features)

• Set up, operate, and scale a relational database in the cloud with just a few clicks.
• supports MySQL, MariaDB, PostgreSQL, Oracle, Microsoft SQL Server, and the new, MySQL-compatible Amazon Aurora DB engine
• managed service, shell (root ssh) access is not provided
• manages backups, software patching, automatic failure detection, and recovery
• supports use initiated manual backups and snapshots
• daily automated backups with database transaction logs enables Point in Time recovery up to the last five minutes of database usage
• snapshots are user-initiated storage volume snapshot of DB instance, backing up the entire DB instance and not just individual databases that can be restored as a independent RDS instance
• support encryption at rest using KMS as well as encryption in transit using SSL endpoints
• for encrypted database logs, snapshots, backups, read replicas are all encrypted as well

RDS Multi-zone Deployment

• provides high availability and automatic failover support and is NOT a scaling solution
• maintains a synchronous standby replica in a different AZ
• transaction success is returned only if the commit is successful both on the primary and the standby DB
• Oracle, PostgreSQL, MySQL, and MariaDB DB instances use Amazon technology, while SQL Server DB instances use SQL Server Mirroring
• snapshots and backups are taken from standby & eliminate I/O freezes
• during automatic failover, its seamless and RDS switches to the standby instance and updates the DNS record to point to standby
• failover can be forced with the Reboot with failover option

RDS Read Replicas

• RDS does not support all the features of underlying databases, and if required the database instance can be launched on an EC2 instance
• uses the PostgreSQL, MySQL, and MariaDB DB engines’ built-in replication functionality to create a separate Read Only instance
• updates are asynchronously copied to the Read Replica, and data might be stale
• can help scale applications and reduce read only load
• requires automatic backups enabled
• replicates all databases in the source DB instance
• for disaster recovery, can be promoted to a full fledged database
• can be created in a different region for MySQL, Postgres and MariaDB, for disaster recovery, migration and low latency across regions
• RMAN (Recovery Manager) can be used for Oracles backup and recovery when running on an EC2 instance

Amazon DynamoDB - NoSQL, key-value and document database

• fully managed NoSQL database service
• synchronously replicates data across three facilities in an AWS Region, giving high availability and data durability
• runs exclusively on SSDs to provide high I/O performance
• provides provisioned table reads and writes
• automatically partitions, reallocates and re-partitions the data and provisions additional server capacity as data or throughput changes
• provides Eventually consistent (by default) or Strongly Consistent option to be specified during an read operation
• creates and maintains indexes for the primary key attributes for efficient access of data in the table
• supports secondary indexes
  • allows querying attributes other then the primary key attributes without impacting performance.
  • are automatically maintained as sparse objects
• Local vs Global secondary index
  • shares partition key + different sort key vs different partition + sort key
  • search limited to partition vs across all partition
  • unique attributes vs non unique attributes
  • linked to the base table vs independent separate index
  • only created during the base table creation vs can be created later
  • cannot be deleted after creation vs can be deleted
  • consumes provisioned throughput capacity of the base table vsindependent throughput
  • returns all attributes for item vs only projected attributes
  • Eventually or Strongly vs Only Eventually consistent reads
  • size limited to 10Gb per partition vs unlimited
• supports cross region replication using DynamoDB streams which leverages Kinesis and provides time-ordered sequence of item-level changes and can help for lower RPO, lower RTO disaster recovery
• Data Pipeline jobs with EMR can be used for disaster recovery with higher RPO, lower RTO requirements
• supports triggers to allow execution of custom actions or notifications based on item-level updates

Database Services: ElastiCache

• managed web service that provides in-memory caching to deploy and run Memcached or Redis protocol-compliant cache clusters
• can be used state management to keep the web application stateless

ElastiCache with Redis

• like RDS, supports Multi-AZ, Read Replicas and Snapshots
• Read Replicas are created across AZ within same region using Redis’s asynchronous replication technology
• Multi-AZ differs from RDS as there is no standby, but if the primary goes down a Read Replica is promoted as primary
• Read Replicas cannot span across regions, as RDS supports
• cannot be scaled out and if scaled up cannot be scaled down
• allows snapshots for backup and restore
• AOF can be enabled for recovery scenarios, to recover the data in case the node fails or service crashes. But it does not help in case the underlying hardware fails
• Enabling Redis Multi-AZ as a Better Approach to Fault Tolerance

ElastiCache with Memcached

• can be scaled up by increasing size and scaled out by adding nodes
• nodes can span across multiple AZs within the same region
• cached data is spread across the nodes, and a node failure will always result in some data loss from the cluster
• supports auto discovery
• every node should be homogenous and of same instance type

ElastiCache Redis vs Memcached

• complex data objects vs simple key value storage
• persistent vs non persistent, pure caching
• automatic failover with Multi-AZ vs Multi-AZ not supported
• scaling using Read Replicas vs using multiple nodes
• backup & restore supported vs not supported

Database Services: Amazon Redshift

• fully managed, fast and powerful, petabyte scale data warehouse service
• uses replication and continuous backups to enhance availability and improve data durability and can automatically recover from node and component failures
• provides Massive Parallel Processing (MPP) by distributing & parallelizing queries across multiple physical resources
• columnar data storage improving query performance and allowing advance compression techniques
• only supports Single-AZ deployments and the nodes are available within the same AZ, if the AZ supports Redshift clusters
• spot instances are NOT an option

Cheat Sheet - Analytics Services

AWS Data Pipeline

• web service that helps you reliably process and move data between different AWS compute and storage services, as well as on-premises data sources, at specified intervals.
• orchestration service that helps define data-driven workflows to automate and schedule regular data movement and data processing activities
• integrates with on-premises and cloud-based storage systems
• allows scheduling, retry, and failure logic for the workflows

Analytics Services: AWS EMR (Elatic Map Reduce)

• a web service that utilizes a hosted Hadoop framework running on the web-scale infrastructure of EC2 and S3
• launches all nodes for a given cluster in the same Availability Zone, which improves performance as it provides higher data access rate
• seamlessly supports Reserved, On-Demand and Spot Instances
• consists of Master Node for management and Slave nodes, which consists of Core nodes holding data and Task nodes for performing tasks only
• is fault tolerant for slave node failures and continues job execution if a slave node goes down
• does not automatically provision another node to take over failed slaves
• supports Persistent and Transient cluster types
  • Persistent which continue to run
  • Transient which terminates once the job steps are completed
• supports EMRFS which allows S3 to be used as a durable HA data storage

Analytics Services: Amazon Kinesis

• enables real-time processing of streaming data at massive scale
• provides ordering of records, as well as the ability to read and/or replay records in the same order to multiple Kinesis applications
• data is replicated across three data centers within a region and preserved for 24 hours, by default and can be extended to 7 days
• streams can be scaled using multiple shards, based on the partition key, with each shard providing the capacity of 1MB/sec data input and 2MB/sec data output with 1000 PUT requests per second

Kinesis vs SQS

• real-time processing of streaming big data vs reliable, highly scalable hosted queue for storing messages
• ordered records, as well as the ability to read and/or replay records in the same order vs no guarantee on data ordering (with the standard queues before the FIFO queue feature was released)
• data storage up to 24 hours, extended to 7 days vs up to 4 days, can be configured from 1 minute to 14 days but cleared if deleted by the consumer
• supports multiple consumers vs single consumer at a time and requires multiple queues to deliver message to multiple consumers

Cheat Sheet - Application Services

Amazon SQS (Scalable Queue Service)

• fully managed message queuing service that enables you to decouple and scale microservices, distributed systems, and serverless applications. SQS eliminates the complexity and overhead associated with managing and operating message oriented middleware, and empowers developers to focus on differentiating work
• extremely scalable queue service and potentially handles millions of messages
• helps build fault tolerant, distributed loosely coupled applications
• stores copies of the messages on multiple servers for redundancy and high availability
• supports multiple readers and writers interacting with the same queue as the same time
• holds message for 4 days, by default, and can be changed from 1 min – 14 days after which the message is deleted
• message needs to be explicitly deleted by the consumer once processed
• allows send, receive and delete batching which helps club up to 10 messages in a single batch while charging price for a single message
• handles visibility of the message to multiple consumers using Visibility Timeout, where the message once read by a consumer is not visible to the other consumers till the timeout occurs
• can handle load and performance requirements by scaling the worker instances as the demand changes (Job Observer pattern)
• supports delay queues to make messages available after a certain delay, can be used to differentiate from priority queues
• supports dead letter queues, to redirect messages which failed to process after certain attempts instead of being processed repeatedly

message sample allowing short and long polling

• returns immediately vs waits for fixed time for e.g. 20 secs
• might not return all messages as it samples a subset of servers vs returns all available messages
• repetitive vs helps save cost with long connection

SQS Design Patterns

• Job Observer Pattern can help coordinate number of EC2 instances with number of job requests (Queue Size) automatically thus Improving cost effectiveness and performance
• Priority Queue Pattern can be used to setup different queues with different handling either by delayed queues or low scaling capacity for handling messages in lower priority queues

Amazon SNS (Simple Notification Service)

• delivery or sending of messages to subscribing endpoints or clients
• publisher-subscriber model
• Producers and Consumers communicate asynchronously with subscribers by producing and sending a message to a topic
• supports Email (plain or JSON), HTTP/HTTPS, SMS, SQS
• supports Mobile Push Notifications to push notifications directly to mobile devices with services like Amazon Device Messaging (ADM), Apple Push Notification Service (APNS), Google Cloud Messaging (GCM) etc. supported
• order is not guaranteed and No recall available
• integrated with Lambda to invoke functions on notifications
• for Email notifications, use SNS or SES directly, SQS does not work

Amazon SWF

• orchestration service to coordinate work across distributed components
• helps define tasks, stores, assigns tasks to workers, define logic, tracks and monitors the task and maintains workflow state in a durable fashion
• helps define tasks which can be executed on AWS cloud or on-premises
• helps coordinating tasks across the application which involves managing inter-task dependencies, scheduling, and concurrency in accordance with the logical flow of the application
• supports built-in retries, timeouts and logging
• supports manual tasks

SWF Characteristics

• deliver exactly once
• uses long polling, which reduces number of polls without results
• Visibility of task state via API
• Timers, signals, markers, child workflows
• supports versioning
• keeps workflow history for a user-specified time
• AWS SWF vs AWS SQS
• task-oriented vs message-oriented
• track of all tasks and events vs needs custom handling

AWS SWF vs AWS SQS

• task-oriented vs message-oriented
• track of all tasks and events vs needs custom handling

AWS SES

• highly scalable and cost-effective email service
• uses content filtering technologies to scan outgoing emails to check standards and email content for spam and malware
• supports full fledged emails to be sent as compared to SNS where only the message is sent in Email
• ideal for sending bulk emails at scale
• guarantees first hop
• eliminates the need to support custom software or applications to do heavy lifting of email transport

Cheat Sheet - Management Tools

Amazon CloudFormation

• gives developers and systems administrators an easy way to create and manage a collection of related AWS resources
• Resources can be updated, deleted and modified in a orderly, controlled and predictable fashion, in effect applying version control to the AWS infrastructure as code done for software code
• supports Chef & Puppet Integration to deploy and configure right down the the application layer
• supports Bootstrap scripts to install packages, files and services on the EC2 instances by simple describing them in the CF template
• automatic rollback on error feature is enabled, by default, which will cause all the AWS resources that CF created successfully for a stack up to the point where an error occurred to be deleted
• provides a WaitCondition resource to block the creation of other resources until a completion signal is received from an external source
• allows DeletionPolicy attribute to be defined for resources in the template
• retain to preserve resources like S3 even after stack deletion
• snapshot to backup resources like RDS after stack deletion
• DependsOn attribute to specify that the creation of a specific resource follows another
• Service role is an IAM role that allows AWS CloudFormation to make calls to resources in a stack on the user’s behalf
• support Nested stacks that can separate out reusable, common components and create dedicated templates to mix and match different templates but use nested stacks to create a single, unified stack

CloudFormation Template

• is an architectural diagram, in JSON format, and Stack is the end result of that diagram, which is actually provisioned
• template can be used to set up the resources consistently and repeatedly over and over across multiple regions and consists of
• List of AWS resources and their configuration values
• An optional template file format version number
• An optional list of template parameters (input values supplied at stack creation time)
• An optional list of output values like public IP address using the Fn::GetAtt function
• An optional list of data tables used to lookup static configuration values for e.g., AMI names per AZ

Elastic BeanStalk

• makes it easier for developers to quickly deploy and manage applications in the AWS cloud.
• automatically handles the deployment details of capacity provisioning, load balancing, auto-scaling and application health monitoring
• CloudFormation supports ElasticBeanstalk
• provisions resources to support
  • a web application that handles HTTP(S) requests or
  • a web application that handles background-processing (worker) tasks
• supports Out Of the Box
  • Apache Tomcat for Java applications
  • Apache HTTP Server for PHP applications
  • Apache HTTP server for Python applications
  • Nginx or Apache HTTP Server for Node.js applications
  • Passenger for Ruby applications
  • MicroSoft IIS 7.5 for .Net applications
  • Single and Multi Container Docker
• supports custom AMI to be used
• is designed to support multiple running environments such as one for Dev, QA, Pre-Prod and Production.
• supports versioning and stores and tracks application versions over time allowing easy rollback to prior version
• can provision RDS DB instance and connectivity information is exposed to the application by environment variables, but is NOT recommended for production setup as the RDS is tied up with the Elastic Beanstalk lifecycle and if deleted, the RDS instance would be deleted as well

OpsWorks

• is a configuration management service that helps to configure and operate applications in a cloud enterprise by using Chef
• helps deploy and monitor applications in stacks with multiple layers
• supports preconfigured layers for Applications, Databases, Load Balancers, Caching
• OpsWorks Stacks features is a set of lifecycle events – Setup, Configure, Deploy, Undeploy, and Shutdown – which automatically runs specified set of recipes at the appropriate time on each instance
• Layers depend on Chef recipes to handle tasks such as installing packages on instances, deploying apps, running scripts, and so on
• OpsWorks Stacks runs the recipes for each layer, even if the instance belongs to multiple layers
• supports Auto Healing and Auto Scaling to monitor instance health, and provision new instances

CloudWatch

• allows monitoring of AWS resources and applications in real time, collect and track pre configured or custom metrics and configure alarms to send notification or make resource changes based on defined rules
• does not aggregate data across regions
• stores the log data indefinitely, and the retention can be changed for each log group at any time
• alarm history is stored for only 14 days
• can be used an alternative to S3 to store logs with the ability to configure Alarms and generate metrics, however logs cannot be made public
• Alarms exist only in the created region and the Alarm actions must reside in the same region as well

Amazon CloudTrail

• records access to API calls for the AWS account made from AWS management console, SDKs, CLI and higher level AWS service
• support many AWS services and tracks who did, from where, what & when
• can be enabled per-region basis, a region can include global services (like IAM, STS etc), is applicable to all the supported services within that region
• log files from different regions can be sent to the same S3 bucket
• can be integrated with SNS to notify logs availability, CloudWatch logs log group for notifications when specific API events occur
• call history enables security analysis, resource change tracking, trouble shooting and compliance auditing

AWS Certified SysOps Admin - Associate

Monaitoring - Demonstrate ability to monitor availability and performance

• Cloudwatch

AWS Certified Developer – Associate

The AWS Certified Developer – Associate exam validates technical expertise in developing and maintaining applications on the AWS platform. Exam concepts you should understand for this exam include:

• Picking the right AWS services for the application
• Leveraging AWS SDKs to interact with AWS services from your application
• Writing code that optimizes performance of AWS services used by your application
• Code-level application security (IAM roles, credentials, encryption, etc.)

Suggested White Papers:

• AWS Whitepaper: Architecting for the Cloud Best Practices
• AWS CDA Exam Blueprint
• AWS Whitepaper: Backup, Archive and Restore Approaches Using AWS
• AWS Whitepaper: Security Best Practices
• AWS Whitepaper: AWS Overview
• AWS Whitepaper: AWS Development and Test on Amazon Web Services
• AWS Whitepaper: AWS Well-Architected Framework
• AWS Whitepaper: Overview of Security Processes
• AWS Whitepaper: How AWS Pricing Works
• AWS Whitepaper: Amazon Virtual Private Cloud Connectivity Options
• AWS Whitepaper: Serverless Architectures with AWS Lambda
• AWS Whitepaper: Running Containerized Microservices on AWS
• AWS Whitepaper: Practicing Continuous Integration and Continuous Delivery on AWS
• AWS Whitepaper: Optimizing Enterprise Economics with Serverless Architectures
• AWS Whitepaper: Microservices on AWS
• AWS Whitepaper: Blue/Green Deployments on AWS

Review Concepts:

• AWS Global Infrastructure
• Shared Responsibility Security Model

Compute: 4 services depending on what we want to do

• EC2
• ECS = container images, less that you can control
• Elastic Beanstalk
• Lambda

Storage Databases:

• RDS = fully managed SQL databases
• DynamoDB = Serverless NoSQL database
• ElastiCache = In-memory Cache Engine
• Redshift = Petabyte-Scale Data Warehouse

Security:

• IAM

AWS Certified Security - Specialty Certification

Linux Academy: lucid charts @adriancantrill linkedin

Whitepapers to Read

• AWS Certified Security Specialty Exam Blueprint
• White Paper: NIST Cybersecurity Framework
• White Paper: AWS Best Practices for DDoS Resiliency
• AWS Security Checklist

IAM - Identity & Access Management

Essentials

• Applies globally to all AWS regions
• Common use: Users, Groups, Roles, IAM Access Policies, API Keys, Specify a pwd policy
• Default: Non-explicit deny rule set up on all new IAM users
• Non-root users: permissions must be given that grant AWS service

ROOT Best Practices:

• Delete root access keys
• Activate MFA (hard or soft)
• Create individual IAM users
• Create user group to assign permissions
• Apply an IAM password policy

Policies

• Explicit deny policy always override an explicit deny policy
• AWS Managed Policies
• JSON editor or Visual editor
• Effect: Deny / Allow
• Action:
• Resources:
• Set Actions only using MFA
• Set Actions only from a specific IP address

Users

• Explicit deny is the default
• Can add policies to users

Groups

• Can assign users to groups
• Attach a policy to the group

Roles

• Connect resources (like a bucket) or access outside of AWS (such as a hybrid environment)
• A role is something another entity can assume
• Policies can not be attached directly to AWS services
• You should always use roles to assign access to an EC2 instance. Never store keys in an EC2 instance.
• Only one role can be applied to an EC2 instances

STS (Security Token Service) - short term credentials to give access to an AWS resource

• EC2 can access S3 temporarily
• An application would never have long term access in a Dev Env
• When generated can only use via API calls
• Security Token, Access Key, Secret Access Key
• Uses: Enterprise ID fed, Web ID fed, Between AWS accounts

Cloudwatch

• Monitor metrics regarding AWS services in realtime (UTC)
  • Built-in metrics, custom made metrics, on-prem metrics
• Services: Free metrics from EC2, EBS, RDS
• Retention (1min = 15d, 5min = 63d, 1h = 455)
• Comparisons can be overlayed
• Add Widgets to dashboards
• Alarms can be created
  • Metrics = data we are measuring
  • Thresholds = point notification is wanted
  • Period = defined time before notification
  • Action = change the state && send a notification
• Alarm state
  • OK, Alarm, Insufficient

CloudWatch Alarms

• Cause AutoScaling = trigger the scale up/down scenarios
• Send alarms to EC2 = trigger Recover, Stop, Term, Reboot (using per-instance required)
• Notification to an SNS Topic (and the subscribers such as SQS, Lambda or email/txt)

CloudWatch Events

• Match events and use targets to react in “near” real-time
• Create a rule:
  • Event Source = an operational/state change or scheduled (1 day, 1 hour, 1 min or Cron)
  • Rules = route an event source to a target
  • Targets = services that react to an event
    • EC2, Lambda, ECS
    • Kinesis Data Stream
    • Systems Manager
    • Code projects
    • SNS, SQS
  • Example: When sharing an EBS snapshot, trigger an SNS Topic and Lambda function OR Daily backup of an EBS Snapshot
    • Cloudwatch: Events: Rules: Event Source: shareSnapshot & Lambda Function: make snapshot private
    • Schedule: paste in EC2 instance EBS volumeID & Create a role for this specific resource: Enable the Rule CloudWatch Logs
• Monitor, Store & Access EC2 & On-prem logs (assuming you have an agent installed)
• Setup filters and alarm if incidents happen
• Most common use is to get logs from CloudTrail (auditing mechanism) and Alarm if certain things happen
• Log Event: single record of activity captured into a strem
• Log Stream: sequence of logs events from source/app
• Log Group: collection of log streams with same access control, monitoring and retention settings
• Metric Filters: assigned to log groups to extract data from groups' log streams and convert into a metric data point
• Retention Settions: period of time logs are kept

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