AWS S3 Glacier Restore tool

I've created this tool in purpose of restoring huge number of objects stored in Glacier tier in AWS S3 bucket

Problem

AWS have tier which is called Glacier, it costs a fraction of S3 Standard tier and is primarily used for storing long term backups but it have it's specifics

1. Restore takes up to 48 hours for files to be available for download
2. You need to request retrieval for every single object (file) in bucket
3. You don't know which files are already ready for download and you have to check them all again and againt

Solution

This tool

1. It can generate a list of all objects in bucket if you need to restore whole bucket, or, you can supply your own list of object which you need to retrieve
2. It saves a progress where it left off and list of files it already requested for retrieval so it save you time if you need to check multiple times
3. Is multithreaded so it can request multiple files at once! (this was a huge boost, from days to hours!)
4. Allows you to simply check status of requested files and keep list of files which are already ready for download and does not check them again

Usage

You always need to specify --bucket parameter (name of bucket)
You can specify an --aws-profile parameter to use specified profile from ~/.aws/config

Subcommands

generate-object-list
ganerates a object list into <bucket>.objects file (all objects in bucket)

request-objects-restore
uses <bucket>.objects object list and saves names of already requested objects to <bucket>.progress file

Parameteres:
--retain-for number of days you want to keep objects restored [Required]
--retrieval-tier Standard, Bulk, Expedited (default: Standard) [Optional]
--thread-count (default: num of cpu in your machine) [Optional]

check-objects-status
uses <bucket>.objects object list, compares it to <bucket>.available and check only files which are not already ready for download

Parameters: --thread-count (default: num of cpu in your machine) [Optional]

Generating a list

This command will traverse whole bucket and list all objects inside

./s3_restore.py --bucket <your_bucket> genereate-object-list

If you want to retrieve only some objects, you have to generate list yourself, just paste your object paths to file with name <your_bucket>.objects
in format:

/object1.jpg
/object2.jpg
/some/other/object.jpg
... etc

and run request-objects-restore subcommand

Requesting a retrieval

./s3_restore.py --bucket <your_bucket> request-objects-restore --retain-for 10

Checking objects retrieval status

./s3_restore.py --bucket <your_bucket> check-objects-status

Benchmarks

I did not create any benchmarks but in my case requesting retrieval of 700 000 files took around 6-8 hours (doing it naive way would took several days!)

Performance

For best performance i recommend creating an EC2 Instance (preferably in same region as your bucket, and with many cores to utilize multithreading) and running it from there, latency is so much lower and in benefit of it the request rate is so much higher :)

The AWS S3 POST request limit is around 3500req/s so be aware that there are paralelization limits and set your thread count accordingly (if i remember correctly the request rate for single thread is around 5-10req/s)