Cloud Computing. Adam Barker

Transcription

1 Cloud Computing Adam Barker 1

2 Overview Introduction to Cloud computing Enabling technologies Different types of cloud: IaaS, PaaS and SaaS Cloud terminology Interacting with a cloud: management consoles Launching an instance Connecting to an instance Running your application Clouds / Constraints 2

3 Cloud Computing Cloud computing provides resizable computing capacity that enables users to build and host applications in a data centre Cloud computing characteristics Computing as a utility Pay-per-use (no commitment, utility prices) Elastic capacity - resources can scale up/down on demand Self service interface Resources are abstracted / virtualised 3

4 Cloud Computing To application developers clouds offer: No upfront infrastructure investment Reduced operating cost through utility pricing Elastic on-demand architecture High service availability 4

5 Cloud Computing To providers clouds offer: The opportunity to exploit existing data-centre capacity The opportunity to take advantage of the economies of scale available to purchasers of extremely large volumes of hardware and network capacity. 5

6 Enabling Technologies A combination of technologies matured at the same time to enable Cloud computing Virtual machines Isolated (self contained) guest operating system installation running within a host operating system Multiple isolated OS environments can co-exist on the same computer Java Virtual Machine (JVM) VMWare, XenSource 6

7 Enabling Technologies Virtualised storage Pooling of physical storage from multiple network storage devices into what appears to be a single device, managed centrally Google File System (GFS) Hadoop Distributed File System (HDFS) Web services WS - * / REST 7

8 Cloud Types Resources can be provisioned at different levels of abstraction from the user Infrastructure as a Service (IaaS) delivers raw computer infrastructure as a service, typically through platform virtualisation vendors manage networking, hard drives, virtualisation, operating system etc. Amazon Web Services is an example 8

9 Cloud Types Platform as a Service (PaaS) delivers an application framework as a service hosted framework for applications Windows Azure is an example Software a Service (SaaS) delivers applications as a service Google Mail is an example 9

10 Infrastructure as a Service (IaaS) Applications Data Runtime You manage Middleware O/S Virtualisation Servers Storage Managed by Vendor Networking 10

11 Platform as a Service (PaaS) Applications Data You manage Runtime Middleware O/S Virtualisation Managed by Vendor Servers Storage Networking 11

12 Software as a Service (SaaS) Applications Data Runtime Middleware O/S Managed by Vendor Virtualisation Servers Storage Networking 12

13 Terminology 13

14 Terminology Amazon Web Services (AWS) Infrastructure as a Service (IaaS) cloud as an exemplar Cloud environment Many other vendors supply cloud services and this presentation is not endorsed by Amazon 14

15 Terminology: Machine Images Machine Images: a template that contains a software configuration, e.g., an operating system, application server and applications On the Amazon stack these are called an Amazon Machine Image (AMI) From an AMI you launch instances, which are running copies of the AMI 15

16 Terminology: Instances From a Machine Image you can launch different instance types Instance types are essentially a hardware archetype Users select an instance type based on the amount of memory and computing power 16

17 Instance Types 17

18 Instance Types 18

19 Instance Types 19

20 Terminology: Regions Instances can be deployed into different areas of the world (e.g., North America, Europe, Asia etc.) Amazon calls these different locations Regions Each Region contains multiple Availability Zones Availability Zones are isolated from one another and provide low latency network connectivity to other zones in the same region 20

21 Regions, Availability Zones 21

22 Elastic Compute Cloud (EC2) Amazon Elastic Compute Cloud (EC2) is a service that provides resizable computing capacity in Amazon's data centres enables users to manage Linux/UNIX and Windows server instances can be used to build and host software systems In order to use Amazon EC2 users require an AWS account associated with each account is a credit card such that services can be paid for using the pay-per-use charging model 22

23 Simple Storage Service (S3) When using EC2 you may need to store data The Amazon Simple Storage Service (S3) can be used to store and retrieve large quantities of data S3 stores data as objects within buckets An object is comprised of a file and optionally any metadata that describes that file Users upload a file they want to store to a bucket, once uploaded they can set permissions and add any relevant metadata 23

24 Interacting with a Cloud: Management Consoles 24

25 Management Consoles The simplest way of interacting with cloud resources is through a management console Management consoles provide a Web-based graphical user interface to hosted cloud services 25

26 AWS Management Console The AWS Management Console provides a simple point and click interface to Cloud resources 26

27 Launching an Instance Instances can be launched via the AWS Management Console Once launched the instance will be live and begin incurring usage fees immediately Once an instance is running you will be charged per hour of use Instances are packaged as instance types: a specification that defines the memory, CPU, storage capacity, and hourly cost for an instance Instance types are grouped more broadly into general families and can be launched with a Linux or Windows Operating System 27

28 Amazon Instance Families Standard: have memory-to-cpu ratios suitable for most general purpose applications Micro: provide a small amount of consistent CPU resources and allow you to burst CPU capacity when additional cycles are available. Well suited for web sites that consume significant compute cycles periodically High-CPU: have proportionally more CPU resources than memory (RAM), well suited for compute intensive applications 28

29 Amazon Instance Families High memory: have proportionally more memory resources and are well suited for high throughput applications, such as database and memory caching applications Cluster compute: have a very large amount of CPU coupled with increased networking performance, making them well suited for High Performance Computing (HPC) applications Cluster GPU: provide general purpose graphics processing units (GPUs), with proportionally high CPU and increased network performance for applications that benefit from parallel processing 29

30 Launching an Instance First select the Amazon Machine Image (AMI) type; this specifies the Operating System and packaged software that will be initialised After the AMI has been selected you need to configure the instance details Number of instances to launch Availability zone: which physical data centre your instance will be deployed into Instance type: micro, small, large etc. 30

31 Launching an Instance 31

32 Launching an Instance Configuring security Key pair is a security credential similar to a password which you use to securely connect to your instance after it is running You will be required to name your key pair which consists of a public and a private key The private key should be saved as a.pem file onto a secure location on your desktop A security group defines firewall rules for your instances; these rules specify which incoming network traffic should be delivered 32

33 Launching an Instance 33

34 Launching an Instance Once launched your instance will be running on one of the Amazon data centres It will be assigned a public DNS name 34

35 Connecting to an Instance Use this public DNS name to connect to your running instance in the cloud via SSH Use the private key which was generated earlier as an argument to the command ssh -i GSG_Keypair.pem ec2- ws.com You're now logged in as ec2-user and can work with the instance like you would any normal server 35

36 Connecting to an Instance 36

37 Running your application Amazon Web Services is an IaaS cloud provider Amazon give you root access to that instance You can therefore install relevant packages, code and data in order to run your application 37

38 Programming Libraries Cloud providers commonly provide language specific programming libraries These libraries remove the complexity from coding directly against a Web service interface Provide a more abstract interface Hides the low-level plumbing including authentication, error handling etc. Provide much of the same functionality Calls to services are still sent over SOAP it s just hidden from the end-user 38

39 Programming Libraries Amazon Web Services (AWS) provide a Software Development Kit (SDK) for (amongst others) the following languages: Java.NET PHP Android ios 39