SE422X Midterm

Amazon ElastiCache

-Amazon ElastiCache is a managed service that makes it easier to launch, manage, and scale a distributed in-memory cache in the AWS cloud -improve response time of cloud applications -much faster than database read

key topics of IaaS

-Resource provisioning -virtual machines -provider manages infrastructure -pay-per-use/pay-as-you-go

amazon simple email service

-a bulk and transactional email sending service from amazon -outbound only email sending service that allows application hosted in the Amazon cloud to send emails (marketing emails) -uses content filtering to scan outgoing messages -accessed and used from SES console, Simple Mail Transfer Protocol (SMTP) interface or SES API

Amazon Redshift

-a fast, massive-scale fully managed data warehouse service -redshift is designed for OLAP use cases and specializing in handling queries on datasets of sizes up to a petabyte or more -provides columnar storage and advanced data compression, enabling fast searches on keys

characteristics of salesforce sales cloud

-accounts, contacts -leads, opportunities -reports, dashboards -campaigns -tasks, activities -products, assets, quotes -calendars, events -forecasts, territory management -chatter -custom apps, tabs, objects -self service portal -cases, solutions

goal of load balancing

-achieve max utilization of resources -minimize response times -maximize throughput

monitoring

-allow cloud users to collect and analyze the data on various monitoring metrics -monitoring service collects data on various system and application metric from the cloud computing instances -monitoring of cloud resources is important because it allows the users to keep track of the health of applications and services deployed in the cloud

photo gallery application -what framework was used -where is the application deployed -what is used for storage -where are records maintained

-application is implemented in python and uses the Flask web framework -Flask application is deployed on an Amazon EC2 instance -photos are uploaded to the application are stored in an Amazon S3 bucket -The records of photos are maintained in a MySQL database instance of Amazon RDS

SDN key elements

-centralized network controller -programmable open APIs -standard communication interface (OpenFlow)

load balancing

-cloud computing resources can be scaled up on demand to meet the performance requirements of applications -load balancing distributes workload across multiple servers to meet the application workloads

monitoring metrics

-cpu: cpu usage, cpu idle -disk: disk usage, bytes/sec (read/write), operations/sec -memory: memory-used, memory-free, page-cache -interface: packets/sec (incoming/outgoing), octets/sec (incoming/outgoing)

workflow for aggregating sensor data in the cloud

-data aggregation-> each incoming data stream is mapped to a data aggregator -data preprocessed to make the data analysis using cloud-based parallel processing frameworks more efficient -data aggregators buffer streaming data into larger chunks -filter data and remove bad records -compress and archive to cloud storage

steps in iterative process of deployment design

-deployment design -performance evaluation -deployment refinement

amazon CloudFormation

-deployment management service from Amazon -can create deployments from a collection of AWS resources such as amazon elastic compute cloud, elastic block store, SNS, elastic load balancing and auto scaling a collection of AWS resources that you want to manage together are organized into a stack

key topics of PaaS

-development and deployment (deploy using cloud tools) -provider manages infrastructure (servers, network, operating systems storage) -user manages application (developing, deploying, configuring, and managing applications)

cloud computing for transportation systems what are they driven by?

-driven by data collected from multiple sources which is processed to provide new services to stakeholders -collect large amounts of data from various sources and process data into useful information -this provides new services like advanced routing guidance, dynamic vehicle routing, anticipating customer demands for pickup and delivery problem

Hardware Virtualization

-enabled by hardware features such as Intels virtualization technology -privileged and sensitive calls are set to automatically trap to the hypervisor -no need for wither binary translation or para-virtualization

what are the three distribution strategies that redshift supports

-even distribution in which rows are distributed across the slices in a round-robin fashion -key distribution in which rows are distributed on the values in one column -all distribution on which a full copy of the data is distributed to every node

para-virtualization

-guest OS is modified to enable communication with the hypervisor to improve performance and efficiency -guest OS kernel is modified to replace non-virtualizable instructions with hyper-calls that communicate directly with the virtualization layer hypervisor

pro v con of NoSQL DB

-have better horizontal scaling capability and improved performance for big data -have less rigorous consistency models

predicting faults in energy systems

-have unique signatures such as increase in temperature, vibration levels -ML algorithms can analyze machine sensor data -clustering algorithms can help in fault isolation -case-based reasoning (CBR) is another popular method that has been used for fault predicition

adoption of IaaS

-individual users: low -small and medium enterprises: medium -large organizations: high -government: high

PaaS adoption

-individual users: low -small and medium enterprises: medium -large organizations: high -government: medium

cloud reference model layers

-infrastructure and facilities layer -hardware layer -virtualization layer -platform and middleware layer -service management layer -application layer

salesforce innovations

-lightning for gmail (see all contextual records related to every email) -lightning dialer voicemail drop (leave voice mails for a list of related prospects with a single click, pre-record a general message) -einstein automated contacts (helps to maintain clean and accurate data, analyzes email and calendar events) -lightning contact hierarchy (view 2000 records on a single user friendly display) -lightning report builder (create multiple reports, access data in minutes)

benefits SaaS

-lower costs -no infrastructure required -seamless upgrades -guaranteed performance -automated backups -easy data recovery -secure -high adoption -on the move access

benefits of PaaS

-lower upfront and operations costs -no IT infrastructure management costs -improved scalability -higher performance -secured access -quick and easy development -seamless integration

characteristics SaaS

-multi-tenancy -on demand software -open integration protocols -social network integration

characteristics of PaaS

-multi-tenancy -open integration protocols -app development tools and SDKs -analytics

characteristics of IaaS

-multi-tenancy -virtualized hardware -management and monitoring tools -disaster recovery

what are some cons of relational databases

-performance is the major constraint for RDs, depends on number of relations and the size of the relations, scaling out is difficult -limited support for complex data structures -complete knowledge of database is required to create ad hoc queries -some relational DBs have constraints on size of field -setting up and maintaining can be difficult -integrating data from multiple relational dbs can be cumbersome

how many databases can a redshift cluster have? how is each compute node partitioned? what is the leader node?

-redshift cluster can have one or more databases where each database can have multiple tables -each compute node is partitioned into slices and each slice is allocated a portion of the nodes memory and disk space -the leader node manages the distribution of data to slices

load balancing algorithms

-round robin -weighted round robin -low latency -least connections -priority -overflow

salesforce clouds

-sales cloud -service cloud -marketing cloud -health cloud -app cloud -community cloud -analytics cloud -IoT cloud -chatter cloud -commerce cloud -Heroku engagement cloud

cloud database services provide

-scalability -reliability -performance (guaranteed performance) -security

cloud storage services provide

-scalability -replication -access policies (access control lists) -encryption -consistency

benefits of IaaS

-shifts focus from IT management to core activities -no IT infrastructure management costs -pay per use or pay as you go pricing -guaranteed performance -secure access -enterprise grade infrastructure -green IT adoption

key topics SaaS

-software/interface (provides users a complete application or user interface to application) -outsourced management -thin client interfaces (browser, platform independent) -access from anywhere

load balancing persistent approaches

-sticky sessions -session database -browser cookies -URL re-writing

what is OpenFlow

-the broadly accepted SDN protocol for the southbound interface -forwarding plane of the network devices van be directly accessed an manipulated -open flow uses the concept of flows to identify network traffic based on predefined match results -flows can be programmed statically or dynamically by the SDN control software -OpenFlow protocol is implemented on both sides of the interface between the controller and the network devices

replication

-used to create and maintain multiple copies of data in the cloud -cloud enables rapid implementation of replication solutions for disaster recovery for organizations -types = array based replication, network based replication, host-based replication

performance evaluation

-verify whether the application meets the performance requirements with the deployment -involves monitoring the workload on the application and measuring various workload parameters such as response time and throughout -utilization of servers in each tier is also monitored

full virtualization

-virtualization layer completely decouples the guest OS from the underlying hardware -the guest OS requires no modification and is not aware that it is being virtualized -full virtualization is enabled by direct execution of user requests and binary translation of OS requests

hypervisor

-virtualization layer consists of a hypervisor or a virtual machine monitor -hypervisor presents a virtual operating platform to a guest operating system (OS)

what are the 12 rules of relational databases

1. information rule 2. guaranteed access rule 3. systematic treatment of null values 4. dynamic online catalog based on relational model 5. comprehensive sub-language rule 6. view updating rule 7. high level insert, update, delete 8. physical data independence 9. logical data independence 10. integrity independence 11. distribution independence 12. non-subversion rule

what is A in ACID? what does it stand for and what does each part mean?

A = atomicity -> ensures that each transaction is either all or nothing. An atomic transaction ensures that all parts of the transaction complete or the database state is left unchanged

What is cloud computing?

A model for enabling ubiquitous, convenient, on-demand network access to a shared pool of configurable computing resources that can be rapidly provisioned and released with minimal management effort or service provider interaction

relational databases provide ______

ACID gaurantees

examples of IaaS

AWS EC2, RackSpace, GoGrid

what is the guarantee of NoSQL DB

BASE Basically Available Soft-state Eventually-consistent

what is C in ACID?

C = consistency ensures that each transaction brings the database from one valid state to another. in other words, the data in a database always conforms to the defined schema and constraints.

what is D in ACID?

D = durability ensures that once a transaction is committed the data remains as it is i.e. it is not affected by system outages such as power loss. Durability guarantees that the database can keep track of changes and can recover from abnormal terminations

what is I in ACID?

I = isolation ensures that the database state obtained after a set of concurrent transactions is the same as would have been if the transaction were executed serially. This provides concurrency control i.e. the results of incomplete transactions are not visible to other transactions. The transactions are isolated from each other until they finish

cloud computing for education -MOOCs

MOOCs are aimed for large audiences and use cloud technologies for providing audio/video content, readings, assignment and exams cloud based auto grading applications used for auto grading, cloud based applications for peer grading of exams and assignments

MapReduce phases

Map Phase: data read from distributed file system, partitioned among a set of computing nodes in the cluster and sent to the nodes as a set of key value pairs; map tasks process the input records independently of each other and produce intermediates results as key value pairs; intermediate results are stored on the local disk of the node running the map task Reduce phase: when all map tasks are completed, the reduce phase begins in which the intermediate data with the same key is aggregated

what is OLAP

Online analytical processing -referred to as data warehouses, which allow the analysis of data for making business decisions -have a lower volume of transactions compared to OLTP systems but queries are more complex

what is RDS scaling (vertical vs horizontal)

RDS databases can be scaled either vertically or horizontally -vertical scaling = choose a diff DB instance size/class to scale up or scale down a database based on the applications workload requirements -horizontal scaling = scaling of a database can be achieved with sharding or read replicas

what is RDS Multi-AZ deployments

RDS supports multi-AZ deployments where a database cluster can be created that spans across multiple availability zones choosing this deployment option when creating a DB instance means RDS creates a replica in a diff availability zone to provide data redundancy, eliminate I/O freezes and minimize latency spikes during system backups primary and secondary instance

SaaS examples

Salesforce.com, Office 365, Facebook, DropBox, LinkedIn, Google Apps, Slideshare

cluster

a cluster consists of one or more hosts and a primary storage. a host is a compute node that runs guest virtual machines

identity access management is enabled by

a number of technologies like OpenAuth, Role based access control, digital identities, security tokens, identity providers

relations

a relational database has a collection of relations or tables. a relation is a set of tuples (or rows)

virtual labs

access to virtual labs is provided to distance learning students through the cloud virtual labs provide remote access to the same software and application that are used by students on campus

AP system

achieve eventual consistency, some clients may read inconsistent data ex: amazon dynamoDB, cassandra

what is a consistent system

all clients always have the same view of data one in which all reads are guaranteed to incorporate the previous writes in a consistent system after an update operation is performed by a writer it is seen by all the readers

analytics services

allow analyzing massive data sets stored in the cloud either in cloud storages or in cloud databases using programming models such as MapReduce

email services

allow application hosted in the cloud to send emails

notification services (or push messaging service)

allow application to push messages to internet connected smart devices such as smartphones, tablets, etc.

application runtimes and frameworks

allow developers to develop and host application in the cloud support various programming languages (Java, Python or Ruby) Resource allocation - automatically allocate resources for applications and handle the application scaling without the need to run and maintain servers

identity and access management services

allow managing that authentication and authorization of users to provide secure access to cloud resources can manage user identifiers, user permissions, security credentials and access keys

storage services

allow storage and retrieval of any amount of data at any time from anywhere on the web organize data into buckets or containers

deployment and management services

allow you to easily deploy and manage applications in the cloud these services automatically handle deployment tasks such as capacity provisioning, load balancing, auto-scaling, and application health monitoring

database services

allow you to set up and operate relational or non relational databases in the cloud

salesforce service cloud snap-ins for lightning communities

allows offering personalized customer services with real-time live chat

salesforce service cloud lightning service setup

allows setting up lightning communities and knowledge base with instructional videos

salesforce service cloud lightning field service parts requests and transfers

allows track shipping, request, parts, and get new stocks right from phones

amazon identity and access management (IAM)

allows you to manage users and users permissions for an AWS account

what is SNS

amazon simple notification service - a push messaging service

primary key

an attribute can be made a primary key if it does not have repeated values in different tuples

Amazon S3

an online cloud based data storage infrastructure for storing and retrieving any amount of data provides highly reliable, scalable, fast, fully redundant and affordable storage infrastructure

Apache CloudStack

an open source cloud software that can be used for creating private cloud offerings manages network, storage, and compute nodes that make up a cloud infrastructure installation consists of a management server and the cloud infrastructure that it manages

MySQL what is it?

an open source relational database management system one of the most widely used RDBMS and is a good choice to be a serving database for data analytics applications where data is structured

Platform as a Service (PaaS)

application development frameworks, operating systems and deployment frameworks

reliability

applications deployed in cloud computing environments generally have a higher reliability since the underlying IT infrastructure is professionally managed by the cloud service (characteristic of cloud computing)

Software as a Service (SaaS)

applications, management, and user interfaces provided over a network

public cloud

available for public use or large industry group

community cloud

available for shared use of several organizations supporting a specific community

platform and middleware layer

builds upon the IaaS layers and provides standardized stack of services such as database service, queueing service, application frameworks and run-time environments, messaging services, monitoring services, analytics services

course management platforms

cloud based course management platforms are used for sharing reading materials, providing assignments and releasing grades cloud based collaboration applications such as online forums can help student discuss common problems and seek guidance from experts

Amazon elastic transcoder

cloud based video transcoding service from Amazon can be used to convert video files from their source format into various other native or web formats that can be played on devices such as desktops, mobiles, tablets

Outsourced Management

cloud computing allows users to outsource the IT infrastructure requirements to external cloud providers (characteristic of cloud computing)

cloud computing for education -online learning platforms and collaboration tools

cloud computing is bringing a transformative impact in the field of education by improving the reach of quality education to students through the use of online learning platforms and collaboration tools

reduced costs

cloud computing provides cost benefits for applications as only as much computing and storage resources as required can be provisioned dynamically, and upfront investment in purchase of computing assets to cover worst case requirements is avoided. (characteristic of cloud computing)

performance

cloud computing provides improved performance for application since the resources available to the applications can be scaled up or down based on the dynamic application workloads (characteristic of cloud computing)

measured service

cloud computing resources are provided to users on a pay-per-use model. the usage of the cloud resources is measured and the user is charged based on some specific metric. (characteristic of cloud computing)

Broad network access

cloud computing resources can be accessed over the network using standard mechanisms that provide platform-independent access through the use of heterogenous client platforms such as workstations, laptops, tablets, and smartphones (characteristic of cloud computing)

on-demand self service

cloud computing resources can be provisioned on-demand by the users, without requiring interactions with the cloud service providers. the process of provisioning resources is automated. (characteristic of cloud computing)

rapid elasticity

cloud computing resources can be provisioned rapidly and elastically. cloud resources can be scaled up or down based on demand. (characteristic of cloud computing)

media services

cloud service providers provide various types of media service that can be used by applications for manipulating, transforming, or transcoding media such as images, videos, etc

hybrid cloud

combines multiple clouds (private and public) that remain unique but bound together to offer application and data portability (keep some data on premises and other data off premises)

publisher

communicate asynchronously with subscribers by producing and sending messages to topics

what is the trade off for distributed systems

consistency and availability

subscriber

consumers who subscribe to topics to receive notifications

amazon cloudfront

content delivery service from amazon. can be used to deliver dynamic static and streaming content using a global network or edge locations

conventional network architecture

control and data plane are coupled

fixed pricing

customers are charged a fixed amount per month for the cloud resources

elastic pricing

customers are charged based on the usage of cloud resources

what can SNS do

deliver notifications as SMS, email or SQS queues or any HTTP endpoint

Amazon elastic beanstalk

deployment service that allows you to quickly deploy and manage applications in the AWS cloud

identity and access management for cloud

describes the authentication and authorization of users to provide secure access to cloud resources

capacity planning

determining the right sizing of each tier of the deployment of an application in terms of the number of resources and the capacity of each resource

planning, operations and services in relation to transportation systems

diff transportation solutions can be moved to the cloud to provide a seamless integration between order management, tactical planning, and execution and customer facing processing and systems

CDN (content delivery network)

distributed system of servers located across multiple geographic locations to serve content to end users with high availability and high performance

attributes

each attribute has a domain, which is the set of possible values for the attribute

what is availability with regards to a system

each client can always read or write refers to the ability of the system to respond to all queried without being unavailable a distributed data system is called available when it can continue to perform its operations even in the even of failure of some of the nodes

schema

each relation has a fixed schema that defines the set of attributes (or columns) and the constraints on the attributes

tuples

each tuple in a relation has the same attributes (columns). the tuples in a relation can have any order and the relation is not sensitive to the ordering of the tuples

secondary storage

each zone has a secondary storage that stores templates, ISO images, and disk volume snapshots

pods

each zone has one or more pods. a pod is a rack of hardware comprising of a switch and one or more clusters

deployment design

figure out the number of servers in each tier, computing, memory and storage capacities of servers, server interconnection, load balancing, and replication strategies

online proctoring

for distance learning programs becoming popular through the use of cloud based live video streaming technologies where online proctors observe test takers remotely through video

amazon dynamoDB

fully managed, scalable, high performance NoSQL database service from Amazon provides fast and predictable performance and seamless scalability without any operational overhead

route generation and scheduling

generate end to end routes using combination of route patterns and transportation modes and feasible schedules based on the availability of vehicles

how does an application store data with key value

generate unique key and submit the key value pairs to the database, database uses the key to determine where the value should be stored

PaaS examples

google app engine, windows azure platform, GitHub, OpenStack

ER diagram

graphically represents the entities and their relationships to each other

how are the partitions for the keys determined in key value DB

hash functions are used, partition number for a key is obtained by applying a hash function to the key, hash functions are chosen such that the keys are evenly distributed across partitions

what is the architecture of key value databases

have distributed architectures comprising of multiple storage nodes, data partitioned across the storage nodes by keys

CA system

have problems with partitioning, network problems may stop the system, replication is used ex: RDBMS (MySQL or Oracle)

salesforce service cloud lightning field service preventative maintenance

helps maintaining work orders to stop product breakdown

cloud based content delivery services

include content delivery networks (CDNs)

applications layer

includes SaaS applications such as email, cloud storage application, productivity applications, management portals, customer self service portals

dynamoDB data model

includes tables, items, and attributes table is collection of items and each item is a collection of attributes

what is sharding

involves partitioning a large database into multiple database instance or shards when sharding is used the application needs to be aware of how the data is partitioned to route the queries to the correct shard

CP system

keep data consistent across partitioned models but there is risk of some data becoming available ex: HBase, MongoDB

topic

logical access point and a communication channel

cloud computing for education -online programs

many universities across the world are using cloud platforms for providing online degree programs lectures are delivered through live/recorded video using cloud based content delivery networks to students across the worls

software defined networking

networking architecture that separates the control plane from the data plane and centralizes the network controller control and data planes are decoupled and the network controller is centralized

are there constraints on columns/have fixed schemas in key value DB

no, does not have tables like relational databases

NoSQL Databases

non relational database -becoming increasingly popular with use of cloud computing services -popular for apps which scale of data is massive and data unstructured or real-time performance is more important than consistency -optimized for fast retrieval and appending operations on records -Do NOT have strict schema -records can be in the form of key-value pairs

Amazon DynamoDB

non relational database service from Amazon -fully managed service (automatically spreads the data and traffic for the stored tables over a number of servers to meet the throughput requirements specified by the users) -replication (data is automatically replicated across multiple availability zones to provide data durability)

what is OLTP

online transaction processing -involves several short online transactions -suitable for transaction-oriented apps (ecommerce app) where frequently writing new data, updating or deleting data, maintaining integrity of data

private cloud

operate for exclusive use of a single organization

salesforce service cloud lightning service console

optimize your case fess, case hovers, split view, and keyboard shortcuts

MapReduce

parallel data processing model for processing and analysis of massive scale data

data plane

part of the network that carries the payload data traffic

control plane

part of the network that carries the signaling and routing message traffic

virtualization

partitioning the resources of a physical system (such as computing, storage, network and memory) into multiple virtual resources key enabling technology of cloud computing that allow pooling of resources in cloud computing resources are pooled to serve multiple users using multi-tenancy

virtualization layer

partitions the physical hardware resources into multiple virtual resources that enable pooling of resources

hardware layer

physical compute, network, and storage hardware

relational database

popular relational databases provided by various cloud service providers include MySQL, Oracle, SQL Server

reduce cost of education

potential in helping bring down the cost of education by increasing the student-teacher ratio through the use of online learning platforms and new evaluation approaches without sacrificing quality

what are some pros of relational databases

pros -well-defined consistency model (app on one RD can be easily changed to run on another RD) -provide ACID guarantees -relational integrity maintained through entity and referential integrity constraints -well suited for OLTP applications -sound theoretical foundation, tried and tested, stable and standardized databases available -database design and normalization steps are well defined and the underlying structure is well understood

compute services

provide dynamically scalable compute capacity in the cloud compute resources can be provisioned on demand in the form of virtual machines

IDAM services

provided by cloud service provider for management of user identifiers and user permissions allow organizations to centrally manage users, access permissions, security credentials and access keys allow creation of user groups where all the users in a group have the same access permissions

service management layer

provides APIs for requesting, managing and monitoring cloud resources

what model are notification services based on? how does it work?

publish-subscribe model in which consumers subscribe to various topics/channels provided by a publisher/producer whenever new content is available on one of those topics/channels, the notification service pushes that information out to the consumer

what are SNS two clients

publisher and subscriber

queueing services (amazon simple queue service = SQS)

queueing service from amazon SQS is a distributed queue that supports messages of up to 256 KB in size SQS supports multiple writers/readers SQS ensures high availability for delivering messages, SQS service trade-offs on the first in-first out capability and does not guarantee that messages will be delivered in FIFO order

insert/update/delete

relations can be modified using insert, update, and delete operations. every relation has a primary key that uniquely identifies each tuple in the relation

Type 1 hypervisor

run directly on the host hardware and control the hardware and monitor the guest OS

Type 2 hypervisor

run on top of a conventional (main/host) operating system and monitor the guest operating systems

what are CDNs useful for

serving static content such as test, images, scripts, etc and streaming media

Key-value database what kind how does it work

simplest form of NoSQL database -store data in the form of key-value pairs, keys are used to identify uniquely the values stored in the databases

spot pricing

spot pricing models offer variable pricing for cloud resources which is driven by market demands

virtual machines can be created from ____ provided by the cloud service provider or ____ created by the users

standard images custom images

What is the CAP theorem?

states that under partitioning a distributed data system can either be two of the three CAP items (consistency, availability, partition tolerance)

what is a document database

store semi-structured data in the form of documents which are encoded in diff standards such as JSON, XML, BSON, YAML. semi-structured = docs stored are similar to each other but no strict requirements for schema

what is partition tolerance

system works well despite physical network partitions refers to the ability of the system to continue performing its operations in the event of network partitions

Network Function Virtualization (NFV)

technology that leverages virtualization to consolidate the heterogenous network devices onto industry standard high volume servers, switches, and storage -NFV can provide the infrastructure on which SDN can run -NFV and SDN are mutually beneficial to each other but not dependent -NFV comprises of network functions implemented in software that run on virtualized resources in the cloud -NFV enables a separation of the network function which are implemented in software from the underlying hardware

resource pooling

the computing and storage resources provided by cloud service providers are pooled to serve multiple users using multi-tenancy. (multi-tenant aspects of the cloud allow multiple users to be served by the same physical hardware) (characteristic of cloud computing)

zones

the management server manages one or more zones where each zone is typically a single datacenter

multi-tenancy

the multi-tenanted approach of the cloud allows multiple users to make use of the same shared resources in virtual multi-tenancy, computing and storage resources are shared among multiple users in organic multi-tenancy every component in the system architecture is shared among multiple tenants (characteristic of cloud computing)

infrastructure and facilities layer

the physical infrastructure such as datacenter facilities, electrical and mechanical equipment

primary storage

the primary storage of a cluster stores the disk volumes for all the virtual machines running on the hosts in that cluster

benefit of using document database over key value databse

these databases allow efficiently querying the documents based on the attribute values in the documents document databases are useful for application that want to store semi-structured data with a varying number of fields

information management

universities, colleges and schools can use cloud based information management systems to improve administrative efficiency, offer online and distance education programs, online exams, track progress of students, collect feedback from students

fleet tracking

use GPS technology to track location of vehicles in real-time -use data to detect bottlenecks in supply chain

what doe push notifications help

used for smart devices as they help in displaying the latest information while remaining energy efficient

deployment refinement

various alternatives can exist in this step such as vertical scaling (scaling up), horizontal scaling (scaling out), alternative server interconnections, alternative load balancing and replication strategies for instance

Infrastructure as a Service (IaaS)

virtual computing, storage and network resource that can be provisioned on demand

Amazon relational database service (RDS)

web service that makes it easy to set up, operate, and scale a relational database in the cloud

Amazon RDS

web service that makes it easy to setup and operate and scale a relational databased in the cloud

when does a network partition occur

when two or more sets of nodes are unable to connect to each other

how do read replicas work

when using read replocas all the write transactions go to a primary database and the read transactions are served from the read replicas

what is the benefit of managed RDS over using your own on-premises database server or a database server running on a cloud instance?

with a managed service you do not need to worry about OS installation and patches, software installation, database engine patches, server maintenance, scalability, and backups RDS service takes care of all these tasks while you can focus on you application development