interview prep Flashcards
what is REST API
Representational state transfer (REST) is a software architectural style that defines a set of constraints to be used for creating RESTFUL web services APIs.
Constraints: stateless where HTTP is used, cacheable, layered system, uniform interface (HTTP methods: get, put, post, delete)
what is a virtual machine
Microsoft: computer file, image that behaves like a computer, meaning computer within a computer.
virtual machine is sandboxed from the rest of the system.
redhat: A virtual machine (VM) is a virtual environment that functions as a virtual computer system with its own CPU, memory, network interface, and storage, created on a physical hardware system
what is a container
unit of software that packages up code and all its dependencies so the application runs quickly and reliably from one computing environment to another.
container vs virtual machine
primary difference:
containers provide a way to virtualize an OS so that multiple workloads can run on a single OS instance.
With VMs, the hardware is being virtualized to run multiple OS instances.
tools for data replication
ETL tools like AWS glue, Talend, mulesoft, etc, AWS read replica RDS,
what is IOPS
input/output operations per second
what is Amazon Machine Image (AMI)
a special type of virtual appliance that is used to create a virtual machine within the Amazon Elastic Compute Cloud
what is AWS AZ
multi availability zone
meaning of multi-AZ db instance
Amazon RDS automatically creates a primary DB Instance and synchronously replicates the data to a standby instance in a different Availability Zone
challenges for data replication
data size, availability, performance, data change rate, consistency
setting up a new ec2 instance
In the Amazon EC2 Dashboard, choose “Launch Instance” to create and configure your virtual machine. In this wizard, you have the option to configure your instance features.
OSI model and layers
Open Systems Interconnection model (OSI model) is a conceptual model that standardises the communication functions of a computing system without regard to its underlying internal structure and technology.
7 Application Data High-level APIs, including resource sharing, remote file access
6 Presentation Translation of data between a networking service and an application; including character encoding, data compression and encryption/decryption
5 Session Managing communication sessions, i.e., continuous exchange of information in the form of multiple back-and-forth transmissions between two nodes
4 Transport Segment, Datagram Reliable transmission of data segments between points on a network, including segmentation, acknowledgement and multiplexing
Media
layers 3 Network Packet Structuring and managing a multi-node network, including addressing, routing and traffic control
2 Data link Frame Reliable transmission of data frames between two nodes connected by a physical layer
1 Physical Symbol Transmission and reception of raw bit streams over a physical medium
Difference between multicast and unicast
Unicast sends IP packets to a single recipient on a network. Multicast sends IP packets to a group of hosts on a network.
Unicast uses TCP (Transmission Control Protocol) for communications while Multicast uses UDP (User Datagram Protocol).
differences: IOPS, latency and throughput
Throughput measures how many units of information a system can process in a period of time. It can refer to the number of I/O operations per second, but is typically measured in bytes per second. … Latency measures the time between issuing a request and receiving a response.
What are the steps involved in migrating customer application from Azure cloud to AWS?
Step 1: Take inventory
understanding the applications you have, the on-premises infrastructure resources supporting them, and the workload dependencies
Step 2: Evaluate applications
Not all applications and workloads are well suited for AWS. When developing a migration plan, it is essential to evaluate the workloads and applications that are candidates for moving to the public cloud.
Step 3: Analyze cost
Migrating applications to public cloud platforms is a business decision that requires both financial and technical assessment. This is particularly important if the migration includes rehosted or refactored applications. If a preliminary assessment of the cost difference for running these applications on-premises vs. in a public cloud is not done, you will most likely get a big cost surprise later.
