Amazon Web Services. Amazon Web Services

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1 Università degli Studi di Roma Tor Vergata Dipartimento di Ingegneria Civile e Ingegneria Informatica Amazon Web Services Corso di Sistemi Distribuiti e Cloud Computing A.A. 2016/17 Valeria Cardellini Amazon Web Services A broad set of services that provides developers with global compute, storage, database, and more advanced services, such as analytics, application and deployment services, messaging Mostly popular for IaaS services and primarily for its elastic compute service EC2 A market leader See 2016 Magic Quadrant for Cloud Infrastructure as a Service by Gartner See AWS analyst reports 1

2 Which services (partial list) Compute Networking & Content Delivery Elastic Compute Cloud (EC2) + - Virtual Private Cloud (VPC) Auto Scaling, Elastic Load Balancing - Route 53 EC2 Container Service - CloudFront Elastic Beanstalk Lambda Lightsail Storage Simple Storage Service (S3) Glacier Elastic File System (EFS) Database DynamoDB Messaging Relational Database Service (RDS) ElastiCache Management Tools CloudWatch Analytics - Elastic MapReduce (EMR) - Kinesis - Data Pipeline - Elasticsearch Service Artificial Intelligence - Machine Learning In red the services we ll see Simple Queue Service (SQS) Simple Notification Service (SNS) Application Services Elastic Transcoder Security, Identity & Compliance Identity and Access Management (IAM) 2 Full list of services from the dashboard 3

3 AWS global infrastructure AWS Regions aws.amazon.com/about-aws/globalinfrastructure/ Geographically dispersed (16 geographic regions) Current regions: US East (Northern Virginia, Ohio), US West (Oregon, Northern California), EU (Ireland, Frankfurt, London), Canada (Central), Asia Pacific (Singapore, Sydney, Tokyo, Seoul, Mumbai), South America (Sao Paulo), China (Beijing) Special AWS GovCloud region for US government agencies and customers (security issues!) Some services are global, i.e., do not require AWS region selection E.g., S3 is a global service Some services are not supported in all the regions See aws.amazon.com/about-aws/global-infrastructure/regional-productservices/ 4 Elastic Compute Cloud (EC2) Provides resizable compute capacity in the cloud Allows to increase/decrease capacity (start/stop instances) within seconds Multiple server instances can be launched simultaneously Instances can be configured for memory, number of vcpus, and storage by choosing T-shirt sizes Pricing: pay-per-use on hourly basis Guarantees complete control over instances Root SSH access, GUI, command line tools, APIs Offers advanced services Elastic Block Store (EBS) Elastic Load Balancer (ELB) CloudWatch + AutoScaling Elastic IP 5

4 EC2 instances: types Computing power of EC2 instances expressed as number of core and EC2 Compute Units (ECU) - 1 ECU = equivalent CPU capacity of a GHz 2007 Opteron or 2007 Xeon processor - See aws.amazon.com/ec2/pricing/ for pricing EC2 instance types aws.amazon.com/ec2/instance-types/ General-purpose (t2, m4, m3) Various T-shirt sizes : nano, micro, small, medium, large, xlarge, 2xlarge Micro instances: very low-cost instance option (included at no charge in AWS Free tier), providing a small amount of CPU resources (good choice for SDCC project development!) Compute optimized (c4, c3) medium, large, xlarge, 2xlarge, 4xlarge, 8xlarge (up to 36 vcpus) Memory optimized (x1, r4, r3) xlarge, 2xlarge, 4xlarge, 8xlarge (up to 1,952 GiB) Storage optimized (i3) xlarge, 2xlarge, 4xlarge, 8xlarge, 16xlarge (up to 8 x 1.9 TB SSD) GPU instances (NVIDIA GPUs) (p2, g2) xlarge, 8xlarge, 16xlarge (up to 16 GPUs) 6 EC2 instances: pricing On-demand instances Billing per-hour with no long-term commitments Read carefully the pricing: Pricing is per instance-hour consumed for each instance, from the time an instance is launched until it is terminated or stopped. Each partial instance-hour consumed will be billed as a full hour Reserved instances One-time payment to reserve an instance for 1 or 3 years Significant discount on hourly usage charge (up to 75%) Spot instances Enable users to bid for unused EC2 capacity Spot price fluctuates in real-time according to supply and demand Run whenever the user bid exceeds the current spot price Can be interrupted by Amazon Allow to lower computing costs for time-flexible, interruptiontolerant tasks 7

5 EC2 instances: pricing Spot instances (continue) Pricing history can be examined before bidding New opportunities for business: companies such as CloudCheckr and Flux7 (VyScale) offer new services for the spot instance market to optimize costs paid by AWS EC2 users 8 Amazon Machine Images Amazon Machine Images (AMIs) are templates from which it is possible to create a virtual machine Contain a software configuration, including an operating system Specified when launching an instance (first step) Created from scratch or bundled from existing EC2 instances Once created, stored in S3 and identified by a unique identifier Personal use Available to other users 9

6 EC2 locations Amazon EC2 is hosted in multiple locations world-wide (AWS Regions) Each region is completely independent Each region consists of one or more availability zones Availability Zones (AZ) Distinct locations in the same region engineered to be insulated from failures in other availability zones AZs in a region are connected through low-latency links Used to protect applications from failure of a single location 10 EC2 interface AWS management console Command Line Interface (CLI) API tools Third-party libraries E.g., boto: AWS SDK for Python (not only EC2) ec2.create_instances(imageid='<ami-image-id>', MinCount=1, MaxCount=5)! Third-party management frameworks 11

7 Elastic Block Store (EBS) Provides persistent block-level storage volumes for EC2 instances Off-instance storage that persists independently from the life of an EC2 instance EBS volumes from 1 GB to 1 TB EBS volume is automatically replicated within its AZ to avoid data loss EBS volume can be adapted as the needs of the applications change (capacity, performance, size) EBS volume can be used at instance s boot partition or attached to running instance EBS volumes attached only to instances in the same AZ 1 EBS volume attached to 1 instance at time (1-to-1), but N EBS volumes attached to a single instance (N-to-1) Can create point-in-time snapshots of volumes stored to S3 12 CloudWatch Provides monitoring for AWS resources (e.g., EC2 instances, DynamoDB tables) and applications running on AWS Used to collect and track metrics CloudWatch alarms send notifications or automatically make changes to monitored resources based on userdefined rules Useful also for cost monitoring E.g., to stop underused instances 13

8 CloudWatch concepts Metric Time-ordered set of data points PutMetricData API allows users to create custom metrics Statistics Metric data aggregated over specified periods of time Available statistics: min, max, sum, average, sample count Retrieved by GetMetricStatistics API Period Length of time associated with a specific CloudWatch statistic Measured in seconds, ranges from 60 (one minute) to (two weeks) Alarm Watches a single metric over a specified time period Performs one or more actions based on the value of the metric relative to a given threshold over a number of time periods 14 CloudWatch metrics EC2 metrics CPU utilization: CPUUTilization! Disk usage: DiskReadOps/DiskWriteOps, DiskReadBytes/DiskWriteBytes Data transfer: NetworkIn/NetworkOut! Elastic Load Balancing metrics Latency! RequestCount: number of completed requests! HealthyHostCount/UnHealthyHostCount: number of healthy/unhealthy instances in each Availability Zone! Count of HTTP response codes (2xx, 3xx, 4xx, 5xx) generated by Load Balancer or back-end instances 15

9 Command line interface Libraries CloudWatch interface Java,.NET, Python, Ruby, Node.js, CloudWatch API Amazon CloudWatch console (also for Android and IoS) 16 CloudWatch Alarms & Auto Scaling An alarm watches a single metric over a time period and performs one or more actions based on the value of the metric relative to a given threshold over a number of time periods Possible states: OK, ALARM, INSUFFICIENT_DATA! When an alarm changes its state, an action is invoked Auto Scaling policy Example Threshold = 3 minimum breach = 3 periods 17

10 Auto Scaling Auto Scaling allows to automatically scale EC2 capacity up or down based on user-defined policies, health status checks, and schedules, e.g., Dynamically based on conditions specified by user (e.g., increasing CPU utilization of the Amazon EC2 instance) Predictably according to a schedule defined by user (e.g., every Friday at 13:00:00). Enabled by Amazon CloudWatch Uses CloudWatch alarms Included with EC2 No additional fee 18 Auto Scaling policies Auto Scaling policy defines actions to take when an alarm state changes For every monitored event, 2 policies to be defined: Scale-in policy Scale-out policy Example: Scale-out: to add new Amazon EC2 instances in increments of 3 instances to the Auto Scaling Group when the average CPU utilization of the Amazon EC2 fleet goes above 70% Scale-in: to remove Amazon EC2 instances in the same increments when CPU Utilization falls below 10% 19

11 Auto Scaling policies (2) A policy can be created or updated using PutScalingPolicy API with parameters (some):! AdjustmentType: possible values are ChangeInCapacity, ExactCapacity, PercentChangeInCapacity! Cooldown: amount of time after a scaling activity completes and before the next scaling activity can start ScalingAdjustment: the amount of instances by which to scale (positive or negative) "ScaleUpPolicy" : {! "Type" : "AWS::AutoScaling::ScalingPolicy",! "Properties" : {! "AdjustmentType" : "ChangeInCapacity",! "AutoScalingGroupName" : { "Ref" : "asgroup" },! "Cooldown" : "1",! "ScalingAdjustment" : "1"! }! }! 20 Elastic Load Balancing (ELB) Automatically distributes incoming traffic across multiple EC2 instances 21

12 ELB features Detects unhealthy instances within a pool and automatically reroutes traffic to healthy instances Enabled across multiple availability zones within a region Not between availability zones in different regions! Uses a least loaded balancing policy Supports sticky sessions Load balancer generated HTTP cookies Application-generated HTTP cookies Supports HTTPS Enables the client to define an application health check for the instances through the following parameters: Threshold, Interval, Target, Timeout, UnhealthyThreshold! Provides APIs to add/remove instances RegisterInstancesWithLoadBalancer! DeregisterInstancesWithLoadBalancer! 22 EC2 and related services problems General problems No real-time billing Performance level of a single VM may be variable and there is very little guarantees regarding the performance of seemingly identical virtual machine instance; e.g., see Resource Provisioning of Web Applications in Heterogeneous Clouds Load balancing policy cannot be customized CloudWatch problems Metric variation over a time interval is missing Request count considers only the requests processed by the load balancer (system throughput behind the ELB) 23

13 EC2 Container service Provides container management service for Docker containers Allows the user to run applications (containerized microservices) on a managed cluster of EC2 instances API to launch and stop Docker-enabled applications, query the cluster state, and access many features (security groups, ELB, EBS volumes, and IAM roles) Integrated with Application Load Balancer Application-layer load balancing option ELB Allows you to define routing rules based on content across multiple services or containers running on EC2 instances No additional charge: the user pays for AWS resources (e.g. EC2 instances or EBS volumes) that creates to store and run the application 24 AWS Lambda Provides compute service that automatically runs the code without requiring the user to provision or manage servers Code for virtually any type of application or backend service Automatically scales the application by running code in response to each trigger Used to build serverless applications composed of functions that are triggered by events and to automatically deploy them using AWS CodePipeline and AWS CodeBuild Fine-grained billing: charged for every 100ms the code executes and the number of times the code is triggered 25

14 Elastic IP & Virtual Private Cloud Elastic IP IP address is not associated with a particular instance but with a user account The user controls an elastic IP address until she/he explicitly releases it Allows to mask instance or availability zone failures by quickly remapping the elastic IP address to another instance/ load balancer Virtual Private Cloud Enables enterprises to connect their existing infrastructure to a set of isolated AWS compute resources via a Virtual Private Network (VPN) connection 26 DNS service: Route 53 Highly available and scalable DNS service Routing queries to infrastructure running in AWS and outside AWS Authoritative DNS server that answers DNS queries with low latency by using a global network of DNS servers Queries are routed to the nearest DNS server through IP anycast Designed to automatically scale to handle very large query volumes without any human intervention Routing to AWS resources Latency-based routing: to the lowest-latency AWS endpoint available Weighted Round Robin: probabilistic selection based on statically assigned weight 27

15 Storage: Simple Storage Service (S3) Distributed, eventually consistent, key value data store Main features Insert, write, read, delete operations on objects up to 5 TB each Objects cannot be manipulated (renamed, modified, relocated) Objects are stored into buckets and retrieved via a unique key Flat structure, with no hierarchy as in a file system (e.g., buckets cannot be nested) The bucket region can be selected and related objects will not leave the region Accessible through REST interface Access control policies, as well as encryption for both secure transit and secure storage on disk Objects are redundantly stored across multiple facilities in an Amazon S3 Region PUT and COPY operations synchronously store data across multiple facilities before returning SUCCESS Data integrity regularly verified using checksum Reduced Redundancy Storage (RRS): storage option to reduce costs by storing data at lower levels of redundancy 28 Databases: DynamoDB Fully managed NoSQL database service that provides fast and predictable performance with seamless scalability Consistency model Eventually consistent reads (default) Strongly consistent reads Automatically spreads the table data and traffic over a sufficient number of servers to handle the request capacity specified by the customer and the amount of data stored, while maintaining consistent, fast performance Data items stored on SSDs and automatically replicated across multiple availability zones in a region Integration with Elastic MapReduce 29

16 Databases: RDS Relational DB (MySQL, Aurora, ) Automatic configuration, management (software patching, backup) and monitoring For MySQL, possible to associate one or more read replicas Read carefully the AWS pricing! Data transfer cost between AWS regions and out from RDS to Internet Remember that you always pay on per-hour basis even if you use the service only for 10 seconds! 30 ElastiCache Provides in-memory cache in the cloud to accelerate applications that rely on slower disk-based storage and databases Supports two open-source in-memory caching engines: Memcached: widely adopted memory object caching system Redis: popular open-source in-memory key-value store that supports data structures such as sorted sets and lists; ElastiCache supports master/ slave replication and Multi-AZ Cautions: consider trade-offs when caching query results (read/write ratio) 31

17 Content delivery: CloudFront Content delivery network on top of the Amazon distributed storage infrastructure Delivers static, dynamic and streaming content using a global network of edge replica servers Requests are routed to the closest edge replica through DNS redirection Objects organized in distributions A distribution identifies the origin server A distribution has a unique CloudFront.net domain name (e.g. mydistribution.cloudfront.net) An origin server is the location of the definitive version of an object This could be another ASW (S3 bucket, Amazon EC2 instance) or an external origin server With respect to other CDNs, pay-per-use pricing 32 Simple Queue Service (SQS) Provides message queuing service that enables asynchronous message based communication between distributed components of an application When a message is received, it becomes locked while being processed If the message processing fails, the lock will expire and the message will be available again 33

18 Big Data: Elastic MapReduce (EMR) Hadoop implementation of MapReduce running on Amazon EC2 Input and output: Amazon S3, DynamoDB Allows to implement data processing applications in many languages including Java, Python, and R Also open-source frameworks in the Hadoop ecosystem can be run on EMR Hive, Pig, HBase, Ganglia (monitoring), Impala (SQL query engine) and Hue (Hadoop UI) Also Spark and Flink Read carefully EMR pricing! You have to pay for: EMR + EC2 (at least medium size) + input/output (S3, DynamoDB) Enable auto-terminate to create a transient cluster 34 Big Data: Kinesis Cloud-based service for real-time data processing over large, distributed data streams Manages the infrastructure, storage, networking, and configuration needed for data stream processing, including data replication across three facilities in an AWS Region Input: events and log data from sources such as servers, desktops, mobile devices, sensors Output: emits aggregated data to other AWS services: S3, EMR and Lambda 35

19 Data Pipeline A web service to reliably process and move data between different AWS compute and storage services, as well as on-premise data sources, at specified intervals 36 Elastic Beanstalk Allows to deploy and manage applications leveraging AWS services (EC2, S3, ELB, Auto Scaling, ElastiCache, SQS) but without the need to manage the corresponding services Supports multiple application environments: Docker, Python, PHP, Node.js,.NET, Ruby, and Java Features Allows to simply and quickly create and manage applications through the console When the developer creates the application environment, Elastic Beanstalk provisions the resources required to run it Allows the developer to customize and configure the environment Environment monitoring Pricing: no additional charge for Elastic Beanstalk, the user pays only for the underlying AWS resources that the application consumes 37

20 Example: Web application on AWS 38 How to obtain your AWS grant Apply to the AWS Educate program See instructions in the specific and follow them! Two main portals: Learning and training material console.aws.amazon.com/console/home Console for AWS cloud services Redeem the credit code before using AWS! Be careful: when your credit expires, your credit card will be charged Check the list of AWS services that are included in the grant How to increase your grant GitHub Student Developer Pack 39

21 AWS Free Tier In addition to your grant AWS Free Tier includes: Services with a free tier available for 12 months following your AWS sign-up date Additional service offers that do not automatically expire at the end of your 12 month AWS Free Tier term See aws.amazon.com/free/ 40 Monitoring AWS usage and costs Various methods, including: Check the pricing of each service (also AWS Price List API) Use CloudWatch to monitor charges with alerts and notifications Create a BillingAlarm Use Cost Explorer from the AWS dashboard See Monitoring AWS usage and costs 41

22 Avoiding unexpected charges Check the pricing of each service before using it! - aws.amazon.com/pricing/services/ - E.g., db.r3.8xlarge for RDS: $4.64 per hour (or fraction of hour) - Some services have linked costs, because services can be launched by other services (e.g., EMR and EC2) - Consider also data transfer pricing (e.g., S3) Stop or terminate unused EC2 instances Stop: you can start the instance again later, but you might be charged for storage Terminate: you permanently delete the instance Deregister unused AMIs Release unused elastic IP addresses See Avoiding Unexpected Charges 42 Avoiding unexpected charges (2) Do not put your secret access keys on GitHub! Protect your access keys Do not have an access key for your root account See Best Practices for Managing AWS Access Keys 43

23 Some useful links AWS Documentation aws.amazon.com/documentation/ AWS Articles & Tutorials aws.amazon.com/articles AWS Instructional Videos and Labs aws.amazon.com/training/intro_series/ AWS Educate site 44