Data Warehouse - Theory Flashcards
What were the user benefits in the shift to cloud computing?
Ease of management (no configuration or backups needed.)
Ubiquity of access, but I need to connectivity
What were the advantages to vendors in the shift to cloud computing?
Software as a service allows faster application development (easier to make changes and improvements)
Improvements and fixes in the software are easier inside their data centers (instead of updating many millions of clients with peculiar hardware and software configurations)
The hardware deployment is restricted to a few well tested configurations
What caused the appearance of warehouse scale computers (WSCs)?
The trends toward server – side computing and widespread Internet services
Define data centers?
They are building where Multiple servers and communication units are co-located because of their common environmental requirements and physical security needs, and for ease of maintenance.
What are the characteristics of a traditional data center?
The typically host a large number of relatively small or medium size applications
Each application is running on a dedicated hardware infrastructure that is decoupled and protected from other systems in the same facility
Applications tend not to communicate with each other
Those data centers host hardware and software for multiple organization units or even different companies
Define the warehouse scale computing
They belong to a single organization, use a relatively homogeneous hardware and systems software platform, and share a common system management layer
What are the characteristics of a warehouse computing?
The only smaller number of very large applications
The common resource management infrastructure allow significant deployment flexibility
The homogeneity off the hardware allow for a more economic purchase, since they are bought in batches, uniform, and patterned way of management, and a more relevant match with the characteristics of the application they run, what leads to a more cost efficient computing power consumption
Does the WSC run small applications, locate traditional data center?
Yes, it does. These kind of applications rely on virtual machines (or containers), and they access large, common services for block or data bases storage, load balancing, and so on, fitting very well with the WSC model.
Why are there multiple data centers located far apart?
In order to reduce user latency and improve serving throughout
Also for disaster recovery in order to keep your service on in case something happens to one data center (redundancy)
There is also the geo political reason which is related to different laws regarding the data management in different countries
What is and how it’s done the hierarchical approach to the data centers locations ?
The world is divided into geographic areas (GAs), the division is done by Geo political boundaries determined mainly by data residency.
The geographical areas are divided into regions (CRs), customers see regions as the finer grain discretization of the infrastructure. The main reasons of the division of areas into regions are for better service provision and for disaster prevention (redundancy).
Finally, the regions are divided into other liability zones (AZs).
What are the servers in a data center?
They are the main processing equipment they differ regarding the CPUs, RAM, local storage, accelerators, and form factor
They are like ordinary PCs, but with a form factor that allow to fit them into the shelves
How are servers interconnected?
They are interconnected by hierarchy of networks
What are the three types of servers regarding to their physical format
The tower server: which are good for scalability and ease of upgrade, cost effective, cools easily. But in the other hand, consumes a lot of space, provide the basic level of performance and complicated cable management
The rack servers: The racks are used to store these rack servers. The server racks are measured in units (U) the advantage of using these racks is that it allows designers to stack up other electronic devices along with the servers
The blade servers: we are the smallest types of servers available at this time and are great for conserving space.
What are the pros and cons of rack servers?
Pros: failure containment (Easy to identify, remove, and replace a malfunctioning server), simplified cable management, cost effective
Cons: power usage (needs of additional cooling system due to their high overall component density), maintenance (gets considerably tough with the increasing number of racks)
What are the pros and cons of blade servers?
Pros: size and form factor (hi space efficiency), cabling (Do not involve the tasks of setting up cabling), centralized management (comes with centralized management that allow administrators to easily monitor, configure and update all blades from a single interface), balancing, failover, scalability
Cons: expensive configuration and higher initial cost, vendor lock-in, cooling (special accommodations have to be arranged for the servers to ensure they don’t get overheated)
