General Flashcards
What is a monolith?
- Big and predetermined - code type picked early and locked in for these large apps
- Large teams - project management resources was highly sequence and orderly
- Development is slow - everything is sequences with large and infrequent changes
What is a microservice? What are the benefits?
With new modern coding, so has the development lifecycle. Microservices function like each of their own services and can use their own programming language.:
Benefits:
- Less risk in change - independent services means less risk to overall applications
- Ability to iterate quickly - teams can improve and fix individual services yielding faster improvements
- Independent scaling - can scale up or scale down depending on demand.
What are the benefits of Cloud Computing?
- On-demand
- Broad network access
- Resource pooling
- Elasticity
- Measured services
What is a relational Relation database (RDBMS)?
is a way of structuring and storing information, use SQL to access the data within them. They have rows and column which are stored in tables (called entities) and get visualized in schema or an ERD.
What a schema?
The term “schema” refers to the organization of data as a blueprint of how the database is constructed. It includes all implementation details such as data types, constraints, foreign or primary keys.
What is an Entity Relationship Diagram (ERD)?
an ERD is the type of graphical schema that’s associated with a relational database: two-dimensional tables. (think detective mind map). Organizing data into rows and columns that exists on tables where those tables are called Entities.
Business user use this.
What is data normalization?
Data normalization is the process of breaking down data into different tables. Cuts down on duplicate data and historically huge costs savings.
Redundant data gets its own table - data types are organized into entities (nouns) and each gets its own tables; cuts down ones and zeroes
This avoids deletion errors - if everything is stored in only one table, deletion has huge impact on records
Computers can’t tolerate missing values - they cannot process nothing; need to be explicitly told when there’s no data in a cell.
Why is Document Model better than RDBMS?
Universal - Includes all universal functionality that developers expect from modern databases. PLUS expressive query language.
Intuitive - JSON, key-value format. If we are exchanging data this way, why not store it this way?
Flexible - no more schema complexity or ORM mapping
Fast - faster to build apps and faster running apps
What is BSON?
Binary JSON (what Mongo uses to address problems above). Uses broader numbers (^&%) to be more efficient, take up less space, and supports data typing.
What is an ORM?
Object Relational Mappers (ORM) - middle layer between front-end application and back-end database - to make it easier for developers to do the things above. Problem is ORM is a huge overhead. Thousands of lines of code to build.
Middleware between app and database - managing a relational database is too difficult so ORM sprang up to make working with them easier
What is RPO? What is RTO?
Recovery Point Objective (RPO) - the amount of data is willing to tolerate losings (how often is data backed up, if you how little tolerance maybe customer makes good copy every 10 mins instead of once a week).
Recovery Time Objective (RTO) - amount of time it takes for an organization to restore from a back up. How long is to take to get that good copy of data on to main computer back online.
What is data validity?
MongoDB can require data validity:
Certain types of data - only allows integers for dollar values, zip codes, phone, etc.
Certain data fields required - for example, creating a new record of a user requires name
Can be setup at any point - an admin could create these rules at the outset or add later
What is ACID?
ACID means certain guarantees
Atomic - CRUD = (creating, reading, updating, delete) is “all or nothing” otherwise the change rolls back
Consistent - ensures data plays by all defined rules, data validity (e.g. enforcing zip code must be integers)
Isolated - changes made to data are invisible to other until completed (if there are conflicts where multiple people are operating on same records - updates are process sequentially or if it breaks it says Erroy xyz)
Durable - software guarantee that things still show up even after the system crashes after the update. Durability means it is not considered complete until update is written to disk.
What does Ops Manager do?
Monitoring and Alerting = 100 DB and hardware metrics that show you what is going on and you can build proactive alerts.
Optimization = ensure everything is running well
Performance Advisory = identifies slow running queries and kill them and make suggestions for new indexes. Strives for a right sized environment. One of the most important functions of a DB is performance.
Automation = reducing hundreds of steps with zero downtime. Great for customers with high 9 uptime needs. It can act as standalone app, web app or restful API.
MDB Enterprise Operator = helps to integrate to Kubernetes
Backups - continuos or snapshot
What are 6 core Atlas capabilities?
- Managed
- Reliable for Mission-Critical Workloads
- Optimal Performance
- Global Data Distribution
- Developer Productivity
- Secure
