Eventually Consistent Data
- S3 replicates data in multiple locations (Az’s), due to this there might be delays while updates to existing objects to propagate across the system. So when we upload a file (which is already existing) there can be a delay of max two seconds. so design your applications accordingly
- Aws uses Read after write as a consistency model
- When two users are trying to read data and at the same time if user 3 tries to write data, write will be done first and read access will be given after write to maintain consitency
- AWS S3 objects can be versioned.
- S3 objects can be versioned while creating the bucket
- Upload a new version of a file
- AWS can enable versioning and suspending versions, bcoz aws will not delete the older version on its own, user has to do it.
- Create an S3 bucket with folders
- Enable versioining after creating the bucket
- Uplod readme.txt in documents folder
- reupload readme.txt with changed content
- verify whether versions are shown by using list versions.
- Create the folder structure in your local system
- Now try to create same folder structure in s3 bucket
- Creating the structure manually is a painfull process if the folder structure is complex
- Solution: AWS CLI Comes to the rescue, So we need to configure aws cli
- How to manage access levels so that not every one will be able to access objects in AWS S3
- Giving access to only few users in your organization to read/write the data
Installing and configuring aws cli
- Refer Here to install and configure aws cli on windows
Ensure you understand Json Format
- Refer Here to understand json.
- Ensure you have the following downloaded into your system
- two audio files
- two video files
- ten images