Part 1 AZ 900 Understand the Concepts (15-20%)
Elasticity
Azure elasticity as a service is referred to a cloud service that enables in automatically scaling Azure hosted resources in par with the demand and configured parameters. It provides Azure Administrators with the ability to auto scale Azure infrastructure and resources as and when needed. Typically, Azure elasticity as a service is delivered through an Azure Monitoring and Automation Software that monitors the systems for certain conditions and automatically scales / downscales infrastructure as needed. How is Azure Elasticity as a Service used? Auto Scale Resources - To add virtual machines, database capacity, and other resources as needed Prevent Downtime - Automatic scaling of resources enables preventing downtimes during peak system / resource demand Deliver reliable cloud Infrastructure - Azure Elasticity as a service enables orchestrating Azure auto scaling on predefined conditions - ensuring that the system continues working even under hightened stress.
Disaster Recovery
Cloud disaster recovery (cloud DR) is a backup and restore strategy that involves storing and maintaining copies of electronic records in a cloud computing environment as a security measure. The goal of cloud DR is to provide an organization with a way to recover data and/or implement failover in the event of a man-made or natural catastrophe. https://azure.microsoft.com/en-us/solutions/disaster-recovery/
Understand terms such as High Availability, Scalability, Elasticity, Agility, Fault Tolerance, and Disaster Recovery
High availability (HA) is a characteristic of a system, which aims to ensure an agreed level of operational performance, usually uptime, for a higher than normal period. Modernization has resulted in an increased reliance on these systems. For example, hospitals and data centers require high availability of their systems to perform routine daily activities. Availability refers to the ability of the user community to obtain a service or good, access the system, whether to submit new work, update or alter existing work, or collect the results of previous work. If a user cannot access the system, it is - from the users point of view - unavailable.[1] Generally, the term downtime is used to refer to periods when a system is unavailable.
Describe Hybrid cloud
Often called "the best of both worlds," hybrid clouds combine on-premises infrastructure, or private clouds, with public clouds so organizations can reap the advantages of both. In a hybrid cloud, data and applications can move between private and public clouds for greater flexibility and more deployment options. For instance, you can use the public cloud for high-volume, lower-security needs such as web-based email, and the private cloud (or other on-premises infrastructure) for sensitive, business-critical operations like financial reporting. In a hybrid cloud, "cloud bursting" is also an option. This is when an application or resource runs in the private cloud until there is a spike in demand (such as seasonal event like online shopping or tax filing), at which point the organization can "burst through" to the public cloud to tap into additional computing resources. Advantages of hybrid clouds: Control—your organization can maintain a private infrastructure for sensitive assets. Flexibility—you can take advantage of additional resources in the public cloud when you need them. Cost-effectiveness—with the ability to scale to the public cloud, you pay for extra computing power only when needed. Ease—transitioning to the cloud doesn't have to be overwhelming because you can migrate gradually—phasing in workloads over time.
Describe Platform-as-a-Service (PaaS)
Platform as a service (PaaS) is a complete development and deployment environment in the cloud, with resources that enable you to deliver everything from simple cloud-based apps to sophisticated, cloud-enabled enterprise applications. You purchase the resources you need from a cloud service provider on a pay-as-you-go basis and access them over a secure Internet connection. Like IaaS, PaaS includes infrastructure—servers, storage, and networking—but also middleware, development tools, business intelligence (BI) services, database management systems, and more. PaaS is designed to support the complete web application lifecycle: building, testing, deploying, managing, and updating. PaaS allows you to avoid the expense and complexity of buying and managing software licenses, the underlying application infrastructure and middleware or the development tools and other resources. You manage the applications and services you develop, and the cloud service provider typically manages everything else.
Scalability
Scalability is the capability of a process, network, software or appliance to grow and manage increased demands. This is one of the most valuable and predominant feature of cloud computing. Through scalability you can scale up your data storage capacity or scale it down to meet the demands of your growing business. Scaling in the cloud provides you the best experience of flexibility of time and money for your business. When business demands are increasing, you can easily add nodes to increase your storage space, or you can increase the number of servers currently used. When the increased demand is reduced then you can move back to your original configuration. Scalability enables you to accommodate larger workloads without disruption or complete transformation of existing infrastructure. To effectively leverage scalability you need to understand the complexity and the types of scalability.
Types of Scalability
Scale Vertically - Scale Up: Vertical Scaling or Scaling up is easy, it can be done by moving the application to bigger virtual machines deployed in the cloud or you can scale up by adding expansion units as well with your current infrastructure. This ability to add resources to accommodate increasing workload volumes is vertical scaling. It can resize your server with no change in your code. The downside to scaling up is that it increases storage capacity but the performance is reduced because the compute capacity remains the same. Workloads requiring higher throughput demand reduced latency and this can only by fulfilled by Horizontal Scaling / Scaling out. Scale Horizontally - Scale out: Horizontal Scaling or Scaling out is the addition of nodes to the existing infrastructure to accommodate additional workload volumes. Contrary to Vertical Scaling, Horizontal Scaling also delivers performance along with storage capacity. The total workload volume is aggregated over the total number of nodes and latency is effectively reduced. This scaling is ideal for workloads that require reduced latency and optimized throughput. Scale Diagonally: Diagonal scaling helps you combine the scaling up and scaling down. As the term suggests, scaling down is the removal of storage resources as requirements decrease. Diagonal scaling delivers flexibility for workload that require additional storage resources for specific instances of time. For instance, a website sets up diagonal scaling; as the traffic increases, the compute requirements are accommodated. As the traffic decreases, the computation capacity is restored to its original size. This type of scaling introduces enhanced budgeting and cost effectiveness for environments and businesses dealing with variable workload volumes.
Understand the consumption-based model
The approach with a consumption-based pricing model is pretty basic. Vendor businesses will quantify the services that they provide, and charge customers according to their use. For example, a messaging service may charge per message. Services that are provided in real time may charge per minute or hour. This is similar to the types of setups that were common in primitive Internet cafés, where café owners charged per minute or hour for the use of broadband services through ISPs. As a main pricing model, consumption-based pricing competes with something called subscription-based pricing. A subscription-based pricing model means that customers simply sign up for Web-delivered services on a daily, monthly or annual basis. Here, customers are not charged per use, but per unit of time as designated by their subscription to services. In other words, within the time frame of their subscription, customers enjoy infinite service use for a flat rate.
Relationship between Availability Features and Disaster Recover
The more you leverage availability features the more disaster proof your system is. the For example, the management of roles across fault domains increases the availability of an application. Without that management, an unhandled hardware failure would become a "disaster" scenario. Leveraging these availability features and strategies is an important part of disaster-proofing your application
Levels of Availability
This level of functionality can take a few forms: completely unavailable, partially available via reduced functionality or delayed processing, or fully available
Describe Software-as-a-Service (SaaS)
ce (SaaS) allows users to connect to and use cloud-based apps over the Internet. Common examples are email, calendaring, and office tools (such as Microsoft Office 365). SaaS provides a complete software solution that you purchase on a pay-as-you-go basis from a cloud service provider. You rent the use of an app for your organization, and your users connect to it over the Internet, usually with a web browser. All of the underlying infrastructure, middleware, app software, and app data are located in the service provider's data center. The service provider manages the hardware and software, and with the appropriate service agreement, will ensure the availability and the security of the app and your data as well. SaaS allows your organization to get quickly up and running with an app at minimal upfront cost.
Agility
he point here is that cloud is a new technology in IT management that has revolutionized the way businesses go to market. And those that don't have the agility to "move quickly and easily" to adapt to these changes are getting left behind. Digging a little deeper into this benefit gets us to WHY this is. In the above example, the retailer needed to add an entirely new business unit. This means acquiring new equipment which means jumping into the dreaded procurement process. Then months of planning, speculating, forecasting, and budgeting ends with a giant, budget-disrupting capital expenditure. But, the cloud's scalability allows a company to bypass all of that. Now, they can work with their cloud provider to quickly and easily add new users, applications, and compute & storage nodes as needed. This radically simplifies the procurement process. The time between provisioning and the commencement of work is dramatically shortened and, before you know it, the new business unit is being rolled out! It's also important to note that cloud is an Operating Expense, NOT a Capital Expense. You pay a monthly fee, so it fits nicely into an Operations budget. This acts to minimizes the budget disruption that a large capital expense can cause and add some agility to your customer's balance sheet. So, Agility in managing IT is crucial in a market that gets more competitive every day. Having the ability to quickly adjust to changing business demands is what will keep your customer's company ahead of the pack. It will also help you maintain your position as Trusted Advisor to their business while building trust and loyalty. Everybody wins!
Understand the principles of economies of scale
https://azure.microsoft.com/en-us/blog/how-to-turn-cloud-economics-to-your-advantage/ In the cloud, this best practice is inverted. Rather than allocating for the maximum load, ask what the minimum footprint is, in terms of instances in the cloud. In the cloud you can always scale up. The important thing, from an economic point of view, is to be attentive to scaling down, to releasing instances and thus reducing charges. You shouldn't pay for what you don't need or use. With Azure, you can configure your application to automatically scale up and down, or you can schedule additional instances when you expect a heavy load, releasing them when no longer needed. Next, think about componentizing. For example; nearly every enterprise application has a Web-facing front end, some business logic, and a database. In the cloud, each of these can be scaled independently. With an effective caching strategy, that is, keeping frequently used data in memory or otherwise readily available, you may be able scale up the front end as user traffic grows while not having to scale the business logic or database server as rapidly - thus intelligently managing cost while at the same time providing a superior experience to users.
Compare and contrast the three different cloud models
https://azure.microsoft.com/en-us/overview/what-are-private-public-hybrid-clouds/
Describe Public cloud
https://azure.microsoft.com/en-us/overview/what-are-private-public-hybrid-clouds/ Public clouds are the most common way of deploying cloud computing. The cloud resources (like servers and storage) are owned and operated by a third-party cloud service provider and delivered over the Internet. Microsoft Azure is an example of a public cloud. With a public cloud, all hardware, software, and other supporting infrastructure is owned and managed by the cloud provider. In a public cloud, you share the same hardware, storage, and network devices with other organizations or cloud "tenants." You access services and manage your account using a web browser. Public cloud deployments are frequently used to provide web-based email, online office applications, storage, and testing and development environments. Advantages of public clouds: Lower costs—no need to purchase hardware or software, and you pay only for the service you use. No maintenance—your service provider provides the maintenance. Near-unlimited scalability—on-demand resources are available to meet your business needs. High reliability—a vast network of servers ensures against failure.
Paired Regions
https://docs.microsoft.com/en-us/azure/best-practices-availability-paired-regions Across the region pairs Azure serializes platform updates (planned maintenance), so that only one paired region is updated at a time. In the event of an outage affecting multiple regions, at least one region in each pair will be prioritized for recovery
Understand the differences between Capital Expenditure (CapEx) and Operational Expenditure (OpEx)
https://www.bmc.com/blogs/capex-vs-opex/ Capital expenditures (CapEx) refers to the money a company spends towards fixed assets, such as the purchase, maintenance, and improvements of buildings, vehicles, equipment, or land. This is also sometimes known as PP&E - property, plant, or equipment. These are major physical goods or services (one-time purchases) intended to benefit the organization for more than one year. In the IT world, these items include IBM Power systems, Intel-based Windows servers, and other high-dollar items, as well as many supporting items, such as Universal Power Systems (UPS), line printers, air conditioners, scanners, and generators. Procurement costs show up on an organization's balance sheet, and the cost is depreciated or amortized over several years, according to the tax code. CapEx spending has pros and cons from the accounting side. If the asset's useful life extends beyond a year, which is typical, the cost is expensed using depreciation, anywhere from 5-10 years. Real estate can be depreciated for over 20 years, for example. Finance teams and bookkeepers applaud these CapEx tax depreciations. On the other hand, the more money put towards capital expenditures means less free cash flow for the rest of the business, which can hinder shorter-term operations. Operating expenses (OpEx) are the funds an organization uses to run its day-to-day business. OpEx items are generally used up within the year they are purchased. Consumables such as printer cartridges, paper, electricity, and other supplies are always purchased under the operating expense budget. Contract items such as yearly service or maintenance agreements, Web site hosting, and Web domain registrations are also purchased as operating expense items, because they are used up within a year. OpEx purchases cover pay-as-you-go items th
Describe Infrastructure-as-a-Service (IaaS)
https://www.bmc.com/blogs/saas-vs-paas-vs-iaas-whats-the-difference-and-how-to-choose/ https://azure.microsoft.com/en-us/overview/what-is-iaas/ Infrastructure as a service (IaaS) is an instant computing infrastructure, provisioned and managed over the internet. It's one of the four types of cloud services, along with software as a service (SaaS), platform as a service (PaaS), and serverless. IaaS quickly scales up and down with demand, letting you pay only for what you use. It helps you avoid the expense and complexity of buying and managing your own physical servers and other datacenter infrastructure. Each resource is offered as a separate service component, and you only need to rent a particular one for as long as you need it. A cloud computing service provider, such as Azure, manages the infrastructure, while you purchase, install, configure, and manage your own software—operating systems, middleware, and applications.
Fault Tolerance
https://www.cloudcodes.com/blog/fault-tolerance-in-cloud-computing.html Explicating Fault Tolerance in Cloud Computing Fault tolerance in cloud computing is about designing a blueprint for continuing the ongoing work whenever a few parts are down or unavailable. This helps the enterprises to evaluate their infrastructure needs and requirements, and provide services when the associated devices are unavailable due to some cause. It doesn't mean that the alternate arrangement can provide 100% of the full service, but this concept keeps the system in running mode at a useable, and most importantly, at a reasonable level. This is important if the enterprises are to keep growing in a continuous mode and increase their productivity levels. Main Concepts behind Fault Tolerance in Cloud Computing System Replication: The fault tolerant system works on the concept of running several other replicates for each and every service. Thus, if one part of the system goes wrong, it has other instances that can be placed instead of it to keep it running. Take for example, a database cluster that has 3 servers with the same information on each of them. All the actions like data insertion, updates, and deletion get written on each of them. The servers, which are redundant, would be in the inactive mode unless and until any fault tolerance system doesn't demand the availability of them. Redundancy: When any system part fails or moves towards a downstate, then it is important to have backup type systems. For example, a website program that has MS SQL as its database may fail in between due to some hardware fault. Then a new database has to be availed in the redundancy concept when the original is in offline mode. The server operates with the emergency database which comprises of several redundant services within.
Describe Private cloud
private cloud consists of computing resources used exclusively by one business or organization. The private cloud can be physically located at your organization's on-site datacenter, or it can be hosted by a third-party service provider. But in a private cloud, the services and infrastructure are always maintained on a private network and the hardware and software are dedicated solely to your organization. In this way, a private cloud can make it easier for an organization to customize its resources to meet specific IT requirements. Private clouds are often used by government agencies, financial institutions, any other mid- to large-size organizations with business-critical operations seeking enhanced control over their environment. Advantages of a private clouds: More flexibility—your organization can customize its cloud environment to meet specific business needs. Improved security—resources are not shared with others, so higher levels of control and security are possible. High scalability—private clouds still afford the scalability and efficiency of a public cloud.
