AWS学习笔记——Chapter2 Storage

前注：
学习书籍<AWS Certified Solutions Architect Associate All-in-One Exam Guide (Exam SAA-C01)>时记录的笔记。
由于是全英文书籍，所以笔记记录大部分为英文。

Storage

1. Three major categories

File: Amazon EFS

Block: Amazon EBS, Amazon EC2 Instance Store

Object: Amazon S3, Amazon Glacier

2. Amazon S3 (Simple Storage Service)

(1) Advantages

Simple, Scalable, Durable, Secured, High performance, Available, Low cost, Easy to manage, Easy integration

Notes:

· Easy integration with third parties, provides REST APIs and SDKs

· Scale up easily though PB data, unlimited data storage

· 99.999999999, data store across multiple data centers and in multiple devices in a redundant manner, sustain concurrent data loss in two facilities

· Data upload -> automatically encrypted； Data transfer -> support SSL；

· Integrate with Amazon CloudFront, delivery web service with low latency

(2) Usage of S3 in real life

Backup
popular for storing backup files among enterprises, data is distributed in three copies for each file between multiple AZs within an AWS region.

Tape replacement

Static web site hosting

Application hosting
can use it for hosting mobile and Internet-based apps.

Disaster recovery

Content distribution
distribute content over internet (directly from S3 or via CloudFront). The content can be anything, such as files, media (photos, videos, …). It can also be a software delivery platform where customers can download software.

Data lake
popular in the world of big data as a big data store to keep all kinds of data. S3 is often used with EMR, Redshift, Redshift Spectrum, Athena, Glue, and QuickSight for running big data analytics.

(A data lake is a central place for storing massive amounts of data that can be processed, analyzed, and consumed by different business units in an organization.)

Private repository
like Git, Yum, or Maven.

(3) Basic concepts

Bucket: a container for storing objects in Amazon S3

Notes: Name must be unique (even across multiple regions)

eg.
object name: ringtone.mp3,
bucket name: newringtones,
file accessible URL: http://newringtones.s3.amazonaws.com/ringtone.mp3

Object: anything store in an S3 bucket is called an object

Notes:
· An object is uniquely identified within a bucket by a name or key and by a version ID.
· Every object in a bucket has only one key.

Region: the object stored in the region never leaves the region unless you explicitly transfer it to a different region.

APIs: allow developers to write applications on top of S3.

Notes:

· REST HTTPS > REST HTTP > SOAP HTTPS

· HTTP verbs correspond to S3 CRUD Operations

GET -> Read, PUT -> Create, DELETE -> Delete, POST -> Create

SDKs: In addition to APIs, lots of SDKs are available in various platforms including in browsers, on mobile devices (Android and iOS), and in multiple programming languages (Java, .NET, Node.js, PHP, Python, Ruby, Go, C++).

Amazon CLI (command-line interface): unified tool to manage all your AWS services.

Notes:

· CLI is often used by Amazon S3 in conjunction with REST APIs and SDKs.

· Through CLI can perform to all the S3 operations from a command line.

(4) Data consistency model

“write once, read many”

Amazon S3 Standard: data store in a minimum of three AZs

Amazon S3-One Zone Infrequent Access: data store in a single AZ

“read-after-write consistency”

Eventually consistent system: the data is automatically replicated and propagated across multiple systems and across multiple AZs within a region, so sometimes you will have a situation where you won’t be able to see the updates or changes instantly.

Update case: if you PUT to an existing key, a subsequent read might return the old data or the updated data, but it will never write corrupted or partial data.

No object locking: the request with the latest time stamp wins. (User can achieve object locking by building it into the application)

(5) Performance considerations

Partition: If the workload you are planning to run on an Amazon S3 bucket is going to exceed 100 PUT/LIST/DELETE requests per second or 300 GET requests per second.

S3 automatically partitions based on the key prefix (chapter2/image/… → ‘c’).

Change the chapter na