S3 get operation only one time? - amazon-s3

Is there any way of allowing only 1 get operation for an S3 file, then have it deleted automatically?
My current implementation depends on a server for downloading from S3 and providing the file to the user, which works but it ends up being a bottleneck when there are too many users...
I am very interested in allowing only 1 get operation for an S3 file, maybe with some kind of policy?
I did some search but found nothing :f

Nope, there is no way (or at least I haven't heard of any) to have such restriction on Amazon S3 servers. But such function could be implemented on you client side.

Related

Flink exact once streaming with S3 sink

I am a newbie in Flink and I am trying to write a simple streaming job with exactly-once semantics that listens from Kafka and writes the data to S3. When I say "Exact once", I mean I don't want to end up to have duplicates, on intermediate failure between writing to S3 and commit the file sink operator. I am using Kafka of version v2.5.0, according to the connector described in this page, I am guessing my use case will end up to have exact once behavior.
Questions:
1) Whether my assumption is correct that my use case will endup to have exact once even though there is any failure occurring in any part of the steps so that I can say my S3 files won't have duplicate records?
2) How Flink handle this exact once with S3? In the documentation it says, it uses multipart upload to get exact once semantics, but my question is, how it is handled internally to achieve exact once semantics? Let's say, the task failed once the S3 multipart get succeeded and before the operator commit process, in this case, once the operator gets restarts will it stream the data again to S3 which was written to S3 already, so will it be a duplicate?
If you read from kafka and then write to S3 with the StreamingDataSink you should indeed be able to get exactly once.
Though it is not specifically about S3, this article gives a nice explanation on how to ensure exactly once in general.
https://flink.apache.org/features/2018/03/01/end-to-end-exactly-once-apache-flink.html
My key takeaway: After a failure we must always be able to see where we stand from the perspective of the sink.

aws s3 sync cli ignoring multipart upload config when syncing between buckets

I'm trying to sync a large number of files from one bucket to another, some of the files are up to 2GB in size after using the aws cli's s3 sync command like so
aws s3 sync s3://bucket/folder/folder s3://destination-bucket/folder/folder
and verifying the files that had been transferred it became clear that the large files had lost the metadata that was present on the original file in the original bucket.
This is a "known" issue with larger files where s3 switches to multipart upload to handled the transfer.
This multipart handeling can be configured via the .aws/config file which has been done like so
[default]
s3 =
multipart_threshold = 4500MB
However when again testing the transfer the metadata on the larger files is still not present, it is present on any of the smaller files so it's clear that I'm heating the multipart upload issue.
Given this is an s3 to s3 transfer is the local s3 configuration taken into consideration at all?
As an alternative to this is there a way to just sync the metadata now that all the files have been transferred?
Have also tried doing aws s3 cp with no luck either.
You could use Cross/Same-Region Replication to copy the objects to another Amazon S3 bucket.
However, only newly added objects will copy between the buckets. You can, however, trigger the copy by copying the objects onto themselves. I'd recommend you test this on a separate bucket first, to make sure you don't accidentally lose any of the metadata.
The method suggested seems rather complex: Trigger cross-region replication of pre-existing objects using Amazon S3 inventory, Amazon EMR, and Amazon Athena | AWS Big Data Blog
The final option would be to write your own code to copy the objects, and copy the metadata at the same time.
Or, you could write a script that compares the two buckets to see which objects did not get their correct metadata, and have it just update the metadata on the target object. This actually involves copying the object to itself, while specifying the metadata. This is probably easier than copying ALL objects yourself, since it only needs to 'fix' the ones that didn't get their metadata.
Finally managed to implement a solution for this and took the oportunity to play around with the Serverless framework and Step Functions.
The general flow I went with was:
Step Function triggered using a Cloudwatch Event Rule targetting S3 Events of the type 'CompleteMultipartUpload', as the metadata is only ever missing on S3 objects that had to be transfered using a multipart process
The initial Task on the Step Function checks if all the required MetaData is present on the object that raised the event.
If it is present then the Step Function is finished
If it is not present then the second lambda task is fired which copies all metadata from the source object to the destination object.
This could be achieved without Step Functions however was a good simple exercise to give them a go. The first 'Check Meta' task is actually redundant as the metadata is never present if multipart transfer is used, I was originally also triggering off of PutObject and CopyObject as well which is why I had the Check Meta task.

Move many S3 buckets to Glacier

We have a ton of S3 buckets and are in the process of cleaning things up. We identified Glacier as a good way to archive their data. The plan is to store the content of those buckets and then remove them.
It would be a one-shot operation, we don't need something automated.
I know that:
a bucket name may not be available anymore if one day we want to restore it
there's an indexing overhead of about 40kb per file which makes it a not so cost-efficient solution for small files and better to use an Infrequent access storage class or to zip the content
I gave it a try and created a vault. But I couldn't run the aws glacier command. I get some SSL error which is apparently related to a Python library, wether I run it on my Mac or from some dedicated container.
Also, it seems that it's a pain to use the Glacier API directly (and to keep the right file information), and that it's simpler to use it via a dedicated bucket.
What about that? Is there something to do what I want in AWS? Or any advice to do it in a not too fastidious way? What tool would you recommend?
Whoa, so many questions!
There are two ways to use Amazon Glacier:
Create a Lifecycle Policy on an Amazon S3 bucket to archive data to Glacier. The objects will still appear to be in S3, including their security, size, metadata, etc. However, their contents are stored in Glacier. Data stored in Glacier via this method must be restored back to S3 to access the contents.
Send data directly to Amazon Glacier via the AWS API. Data sent this way must be restored via the API.
Amazon Glacier charges for storage volumes, plus per request. It is less-efficient to store many, small files in Glacier. Instead, it is recommended to create archives (eg zip files) that make fewer, larger files. This can make it harder to retrieve specific files.
If you are going to use Glacier directly, it is much easier to use a utility, such as Cloudberry Backup, however these utilities are designed to backup from a computer to Glacier. They probably won't backup S3 to Glacier.
If data is already in Amazon S3, the simplest option is to create a lifecycle policy. You can then use the S3 management console and standard S3 tools to access and restore the data.
Using a S3 archiving bucket did the job.
Here is how I proceeded:
First, I created a S3 bucket called mycompany-archive, with a lifecycle rule that turns the Storage class into Glacier 1 day after the file creation.
Then, (with the aws tool installed on my Mac) I ran the following aws command to obtain the buckets list: aws s3 ls
I then pasted the output into an editor that can do regexp relacements, and I did the following one:
Replace ^\S*\s\S*\s(.*)$ by aws s3 cp --recursive s3://$1 s3://mycompany-archive/$1 && \
It gave me a big command, from which I removed the trailing && \ at the end, and the lines corresponding the buckets I didn't want to copy (mainly mycompany-archive had to be removed from there), and I had what I needed to do the transfers.
That command could be executed directly, but I prefer to run such commands using the screen util, to make sure the process wouldn't stop if I close my session by accident.
To launch it, I ran screen, launched the command, and then pressed CTRL+A then D to detach it. I can then come back to it by running screen -r.
Finally, under MacOS, I ran cafeinate to make sure the computer wouldn't sleep before it's over. To run it, issued ps|grep aws to locate the process id of the command. And then caffeinate -w 31299 (the process id) to ensure my Mac wouldn't allow sleep before the process is done.
It did the job (well, it's still running), I have now a bucket containing a folder for each archived bucket. Next step will be to remove the undesired S3 buckets.
Of course this way of doing could be improved in many ways, mainly by turning everything into a fault-tolerant replayable script. In this case, I have to be pragmatic and thinking about how to improve it would take far more time for almost no gain.

How do I access the same bucket using multiple domains on Amazon S3?

I would like to parallelize requests to the resources stored on Amazon's S3 service by accessing them with different domains. I realize that I could just make multiple buckets and make sure the content is always the same. This is annoying however. Everytime I upload something, I have to do it 5 times.
Thanks.
You don't need to do this. S3 should handle many download requests at once. If you need more than that, then use cloud front, which gets the files closer to your clients.
If by 'parallelize requests' you mean something else, then please elaborate.

S3: Duplicate buckets

What is the easiest way to duplicate an entire Amazon S3 bucket to a bucket in a different account?
Ideally, we'd like to duplicate the bucket nightly to a different account in Amazon's European data center for backup purposes.
One thing to consider is that you might want to have whatever is doing this running in an Amazon EC2 VM. If you have your backup running outside of Amazon's cloud then you pay for the data transfer both ways. If you run in an EC2 VM, you pay no bandwidth fees (although I'm not sure if this is true when going between the North American and European stores) - only for the wall time that the EC2 instance is running (and whatever it costs to store the EC2 VM, which should be minimal I think).
Cool, I may look into writing a script to host on Ec2. The main purpose of the backup is to guard against human error on our side -- if a user accidentally deletes a bucket or something like that.
If you're worried about deletion, you should probably look at S3's new Versioning feature.
I suspect there is no "automatic" way to do this. You'll just have to write a simple app that moves the files over. Depending on how you track the files in S3 you could move just the "changes" as well.
On a related note, I'm pretty sure Amazon does a darn good job backup up the data so I don't think you necessarily need to worry about data loss, unless your back up for archival purposes, or you want to safeguard against accidentally deleting files.
You can make an application or service that responsible to create two instances of AmazonS3Client one for the source and the other for the destination, then the source AmazonS3Client start looping in the source bucket and streaming objects in, and the destination AmazonS3Client streaming them out to the destination bucket.
Note: this doesn't work for cross-account syncing, but this works for cross-region on the same account.
For simply copying everything from one bucket to another, you can use the AWS CLI (https://aws.amazon.com/premiumsupport/knowledge-center/move-objects-s3-bucket/): aws s3 sync s3://SOURCE_BUCKET_NAME s3://NEW_BUCKET_NAME
In your case, you'll need the --source-region flag: https://docs.aws.amazon.com/cli/latest/reference/s3/sync.html
If you are moving an enormous amount of data, you can optimize how quickly it happens by finding ways to split the transfers into different groups: https://aws.amazon.com/premiumsupport/knowledge-center/s3-large-transfer-between-buckets/
There are a variety of ways to run this nightly. One is example is the AWS instance-schedule (personally unverified) https://docs.aws.amazon.com/solutions/latest/instance-scheduler/appendix-a.html