CLOUD COMPUTING SEM 3

  Hello students, In this last blog of Unit 3, we look at Data Intensive Computing. Data intensive computing are types of computing problems where data is very huge in numbers and size from few mega bytes to tera bytes to peta bytes to zeta bytes to exa bytes. Such data sizes are called to be Big Data.  There has been data explosion in last many years ever since technology has become mature and advanced.  Relational model based databases made up of tables, records, keys and relationship are not able to  manage Big Data due to huge amount of exponentially growing data and due to its strict structured format and ACID restrictions. NoSQL databases was the answer to Big Data, to all data that was huge in numbers, were unstructured or semi structured.  Big data could be split horizontally as well as vertically into managed datasets, which could be stored in repositories as required.  One could query the datasets to know its content using meta data attributes ...

Dear students, In our last blog, we came across concurrent computing, where the focus was how a single program can be computed faster by decomposing either based on data sets (Domain Decomposition) or based on functionality (Function Decomposition). Once the decomposition is planned properly in the program, it can be assigned to multiple cores or multiple threads. Concurrent computing is a form of parallelism on the same machine. When we talk about task computing, we are looking at executing not single program, but multiple programs. Each program can be considered as a task with lot of data or consisting of many work units. These tasks can be executed using multiple machines. Task Computing is a form of parallelism on multiple machines. It is a network of machines, where one machine (called local node) becomes responsible to submit the task, then one machine schedules it , checks status on all submitted tasks (access nodes) , one machine provides any resources such as files, data...

Hello students, In this blog, we focus on concurrent computing. The word 'concurrent' means at the same time. In computing world, when we execute two programs at the same time, we can say it is concurrent. Concurrency can be achieved by executing two programs on two different processors or if the processor has multiple cores, then concurrency can be achieved by executing two programs on different cores or if we can also run two programs on two different computers at the same time. Throughput Computation When we have a high level of computation to be done in a single program itself to achieve at a result, then parallel computation techniques are used to break down the entire program into independent work units (computational unit) and execute them concurrently. Such computation problems are throughput computing problem. Examples of throughout computation could be scientific modelling, video encoding, gaming, machine learning, deep learning and much more. Multitask...

Hello students, If you are ever asked a question in exam about “Cloud Platform” (not PaaS), remember three cloud platform providers namely AWS, GCP, Azure In this blog we look at the cloud computing features provided by three cloud providers namely Amazon Web Services (AWS) Google Cloud Platform (GCP) Microsoft Azure Cloud Amazon Web Services We look specifically at 13 services provided Amazon Web Services cloud provider 1. Management Console – user interface for customers to use AWS services over the internet 2. Elastic Compute Cloud (EC2) – virtual machine provisioning 3. Internet Users – User access is secured via public key infrastructure and Identity Access Management services 4. Amazon Machine Image (AMI) – linux, windows images are readily available to use and go, with many other complex machine image via AMI services 5. Static Network Addresses – Elastic , public and static IP addresses is available readily for use over the internet 6. Servers – any number o...

Hello students, In this blog, we delve on Multitenant software. As we have known through our Virtualization assignment, Multitenancy is all about taking one physical thing shared with multiple customer.  Cloud implements Multitenancy at all levels, from hardware to software, from infrastructure to platform to software. Virtualization is an example of using one physical machine and creating multiple virtual machines from it.  One processor have multiple cores that can be shared with multiple tasks from different customers.  A network device with multiple ports can be divided into different virtual networks utilized by different customers.  Multitenancy is about supporting multiple entities and hence Multitenancy is all about  Multiple Entity Support. Multitenancy in achieved in SaaS using three techniques Single Schema Model Meta-Data Customization  Multiple Schema Model Single Schema Model A Schema refers to the design. In databases it re...

Dear students, We start our Unit 3 with one of cloud technologies Web 2.0 When internet was born, lot of applications that were created could be termed as Web 1.0. Then Web 2.0 technology enhanced the Web technologies. Web 2.0 covered four different technologies namely SOAP services REST services AJAX services MASHUP services We covered the entire Semester 2 learning about SOAP services and REST services SOAP Services SOAP services utilized SOAP protocol 1.0, 1.1, 1.2. It initially operated using HTTP, was inter-operable between any type of systems, languages, applications. SOAP made application integration easier and was loosely coupled. SOAP utilized XML data structure for any type of communication over HTTP application protocol. SOAP now works on protocol other than HTTP too and is suitable for complex applications. REST services REST services later was introduced to be much simpler that worked in distributed system with simple URI links and plain HTTP CRUD methods (GET...

Hello students, So far we covered the entire classification (taxonomy) of Virtualization. In the business world, Xen, VMWare and HyperV are some of the leading virtualization products. Xen uses ParaVirtualization technique , VMWare uses Full Virtualization technique whereas HyperV uses the both Para and Full Virtualization techniques together Xen and HyperV are Type 1 Hypervisors which run directly over the hardware, whereas VMWare is a Type 2 Hypervisor, which runs above the operating system We dig deeper into Microsoft HyperV in this lecture Some of you may have partitioned your hard disk to install two operating systems on your hard disk. HyperV uses same technique to manage different virtual machine HyperV automatically creates, uses and manages partitioning to enable different guests. It has one master partition managing all other partitions called child partitions We dig further into the enlightened I/O technology utilized by Hyper-V that improves performance by allowing direct...

Hello students, So far we covered the entire classification (taxonomy) of Virtualization. In the business world, Xen, VMWare and HyperV are some of the leading virtualization products. Xen uses ParaVirtualization technique, VMWare uses Full Virtualization technique whereas HyperV uses the both Para and Full Virtualization techniques together We dig deeper into Xen and VMWare in this lecture Xen Xen uses the ring-based ISA security model to prevent any sensitive priviledged instructions been executed by normal users running their their virtual machines. Xen also introduces the feature of web http access to configure and manage the virtual machines over the web. Xen is popularly used by AWS cloud provider. VMWare VMWare was the first company to introduce virtualization. When it arrived, it provided a heavy full virtualization where entire operating system had to be loaded in every virtual machine. VMware also uses ring-based ISA security model. VMware provides three key flavours of vir...

Hello students, In our last lecture we introduce system level virtualization and hypervisor was one of the key software that emulates a machine. Hypervisor is like a middle-person which co-ordinates the process of creating and managing virtual machines on one side and on the other side it manages all system hardware operations, either with the help of operating system or without it, depending which type of Hypervisors it is. When it comes to dealing with system operations, we are essentially dealing with actual physical hardware (actual hard disk, actual memory, actual processor, actual network etc.) via instruction set architecture (ISA) In this lecture, we focus on four techniques that can be utilized by Hypervisors to virtualize the underlying hardware/system Hardware assisted Virtualization (= VMM + custom hardware) Full Virtualization (= full virtual machine inclusive of OS and apps over it) Para Virtualization  (= modified guest OS + thin VM) Partial Virtualization (= Virtu...

Hello students, In todays lecture we dive inside system level emulation . We look at two key system mechanics, the machine and the hypervisor. When we think of system, it refers to the machine hardware (processor, memory, peripheral devices) which understand only machine instructions . Our operating system executes with the help of these hardware specific machine instructions. Machine Reference Model, ISA We begin the lecture by understanding the machine reference model to understand what makes any system work. ISA or Instruction Set Architecture (consisting of machine instructions) is at the core that ultimately manages, controls, instructs this hardware. All our system programs (including operating system) uses ISA to manage, control, instruct the hardware Some ISA instructions can delete, destroy, obstruct your system and hence such sensitive privileged ISA instruction has to be securely managed using ring-based ISA Security model. Hypervisor (Virtual Machine Manager) We finally ...

Hello students, In our last lecture we saw that for any type of virtualization, there are three basic components namely the host, virtualization layer and the guest. In this lecture we have bird's view of taxonomy of Virtualization (classification into categories and types of Virtualization) . Virtualization is emulating some real thing. In our last lecture, we saw how an electric extension board emulates a live electric point. In computers, that real thing which we want to emulate can be a hard disk, or a machine or a operating system etc. Emulating a hard disk, would mean, emulate as if I have my own file system, folders. I should be able to save files in my folder. My emulation copy is private to me and no one else can access it. When we share our desktop to somebody through a software like AnyDesk, it is an emulation of what's happening on the real desktop, onto somebody's remote screen. This is one type of emulation/virtualization example. In specific, this is called...

Hello students, We start with a new topic namely Virtualization in this lecture. You would have come across an electric socket plug point in your house where you put in a plug to connect to one device. That device can be your TV or your mobile charger or your computer. But how does one use the same electric socket to connect to all devices at the same time. I can use an electric extension board which has multiple electric sockets in it as output and the other end is connected to the real single electric socket input point. In this case, your main electric point becomes the "host", the extension board becomes the "virtualization layer" and your TV, mobile and computer become the "guest" Such type of problems are called virtualization type of problems, where you have one physical device that needs to be shared with multiple users at the same time. Though there is one physical device, I may create three or more virtual devices (guest) out of single physical...

Welcome students, In today’s lecture, we dig into architecture (design) that drives service oriented computing (a distributed computing technology). In last blog, I mentioned cloud’s natural choice of technology is by utilizing service oriented technology, which is based on services (aka Web Services / Rest Services). In our last lecture, we also covered the four characteristics that any service has. In this lecture, we look into architecture that drives Service Oriented Computing, namely the Service Oriented Architecture (SOA) . We understand Service Oriented Architecture (SOA). We understand who is a service provider and who is a service consumer. We understand the difference between Service Orchestration and Service Choreography architectures in a SOA based ecosystem. Just like any service has 4 characteristics, any SOA implementation is based on 8 principles. We understand each of these SOA principles. Finally we end our lecture with 5 key advantages of web service...