Microsoft Azure Vocabulary
Cloud is a symbol, metaphor, and abstraction between your business and local computing infrastructure. While, there is globally distributed data centers, which will be owned by the firm and provided by the firm. In this case Microsoft. The same is defined in the diagram above.
Usually, the cloud computing i.e, public cloud in particular is mostly used IT industry. There are some services which most of the IT companies use.
IT services on demand:
- Compute
- Storage
- Networking
- Monitoring
The point here to be noted is that Microsoft has established Azure as an open source. That means it is free of cost for most of the services. But there will be only one thing which is charged for i.e, storage.
Computing: The software is designed according to the infrastructure present for IT firm.
Storage: The firm has to pay for the consumption of the Azure datacenters.
Networking & Monitoring: These both are handled by the cloud providers, in this case Azure Microsoft. There are even other such as AWS amazon and google cloud platform.
All you are working with in your local environment are the tools to interact with Azure resource manager programming interface (API). Tools such as web browser in azure portal, power-shell, azure command line interface, and various software development kits (SDK’s) etc.
Vocabulary:
The Vocabulary we will learn for Azure, will in the context of the Azure architecture.
High Availability:
The design of cloud application is in such a way, that it maximizes the service accessibility.
Note: Do not confuse the high availability with up-time. The up-time is the clock time that a server has been online. If a server is not online due to some other reasons, then it cannot be concluded as available. Hence, it cannot have attribute such as high availability.
Fault Tolerance:
Features such as redundancy, cloning, repetition is applied on to the data. This will ensure zero downtime.
In the architecture diagram we can see that in primary region, in web tier there are 3 virtual machines.
Case1: There is a possibility that 2 out of 3 machines might go down, but in that case the 3rd on will work, maintaining zero down time.
Yet, there is possibility that all of the 3 might go down. Is such case we have case2.
Case2: When all the 3 virtual machines go down, the architecture is designed in such a way, that there is a secondary region in which more 3 virtual machines that are present, which will work when the primary region virtual machines are down. Hence, providing solution for failures at multiple-levels, ensures zero downtime.
Disaster Recovery:
What plan you have in place, suppose you had a service disruption. The idea goes same here as well i.e, having 2 regions, one being disrupted that case one could switch to 2nd region.
In simple words disaster recovery is plan to restore normal operations. The primary region is active region which will be used on a regular basis. While the secondary region is a standby region used in the temporary fall on primary.
Scalability:
Scalability in azure is vertical and horizontal scale-out. In other words it can expand in north south and east west directions. If suppose there is a computer on-premises which is overburdened, then it would be likely to increase its computing power by expanding ram or CPU.
The case with Azure or any public cloud service is that the computing power is a dial, i.e, can increase computing power just by giving a command. This is a example of vertical expansion i.e, shift database to an higher compute tier.
Horizontal scaling can be done manually or automatically by azure. Suppose there is a web app which has high peak usage and needs more instances, in that case Azure will automatically scale the peak and create more new instances.
Elasticity:
It is an ability to dynamically scale out or scale in. In the above horizontal example, the web application instances where increased, which would be expensive if continued. Hence, gradually after the peak the instances must be bought down according to the need.
Agility:
Azure or any other public cloud services, has an ability to create the platform to develop and deploy services quickly.