public cloud in cloud computing
public cloud in cloud computing 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 organisations 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 cloud
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. The public cloud represents services offered by an external party that can be accessed over the Internet. The services are not limited and can be purchased as you consume the service. This is a key difference from an on-premises infrastructure. With the public cloud, you only pay for the amount of service you consume when you use it. For example, I only pay for the amount of storage I am using at any moment in time; the charge does not include the potential amount of storage I may need in a few years’ time. I only pay for the virtual machines I need turned on right now; I can increase the number of virtual machines when I need them and only pay for those extra virtual machines while they are running.
Turn It Off : In Azure, virtual machines are billed on a per-minute basis. If I run an 8-vCPU virtual machine for 12 hours each month, then I only pay the cost for 12 hours of runtime. Note that it does not matter how busy the VM is. You pay the same price whether the vCPUs in the VM are running at 100 percent or 1 percent processor utilization. It’s important to shut down and deprovision from the Azure fabric any virtual machines that are not required to avoid paying for resources you don’t need. ( Deprovision just means the virtual machine no longer has resources reserved in the Azure fabric.) the virtual machine can be restarted when you need it again. At that point, resources are allocated in the fabric automatically; the VM will start as expected.
In addition to the essentially limitless capacity, this pay-as-you-go model is what sets the public cloud apart from on-premises solutions. Think back to organizations needing DR services. Using the public cloud ensures there are minimal costs for providing disaster recovery. During normal running, you only pay for the storage used for the replicated data and virtual environments. Only in the case of an actual disaster would you start the virtual machines in the public cloud. You stop paying for them when you can fail back to on-premises.
There are other types of charges associated with the public cloud. For example, Azure does not charge for ingress bandwidth (data sent into Azure—Microsoft is fully invested in letting you get as much data into Azure as possible), but there are charges for egress (outbound) data.
There are different tiers of storage, some of which are geo-replicated, so your data in Azure is stored at two data centers that may be hundreds of miles apart. The common theme is you pay only for what you use. If most organizations’ IT requirements were analyzed, you would find many instances where resource requirements for a particular service are not flat. In fact, they vary greatly at different times of the day, week, month, or year. There are systems that perform end-of-month batch processing. These are idle all month, and then consume huge amounts of resources for one day at the end of the month. There are companies that are idle for most of the year but that are very busy for two months.
Test and development : Test and development servers are less risky than production workloads and typically has a high amount of churn, means environments are created and deleted frequently. This translates to a lot of work for the IT teams unless the private cloud has been implemented.
Disaster Recovery : As discussed, for most companies a DR action should never be required. However, DR capability is required in that extremely rare event when it’s needed. By using the public cloud, the cost to implement DR is minimal, especially when compared to costs of a second data center.
International DMZ : Number of companies that would like to offer services globally. This can be challenging—having data centers in many countries is hugely expensive and can even be politically difficult. By using a public cloud that is geographically distributed, it’s easy to offer services around the world with minimal latencies for the end users.
Special Projects : Imagine a campaign or special analytics project that requires large amounts of infrastructure for a short period of time. The public cloud is perfect for this, especially when certain types of licensing (for example, SQL Server licensing) can be purchased as consumed and other resources are paid for only as required.
Get Out of the Data center Business : Many companies that just don’t want to maintain data centers anymore. These organizations will move as much as possible to the public cloud and maintain minimal on-premises infrastructure needed for certain services, such as domain controllers and file and print servers.