I have a node.js backend that sends out images to a secondary api for transformations and then those images appear in s3 bucket. The problem is that the secondary api doesn't inform my api when the file is created in the bucket.
Is there some sort of long polling in s3 available because spamming get requests doesn't feel right (also will get expensive).
I'm considering adding a trigger on new files in s3, that will invoke a lambda that will put a message into some sort of pub/sub message broker and then I could just subscribe to it but this seems a bit too complicated?
From the S3 notification docs you can be notified via:
Amazon Simple Notification Service (Amazon SNS) topic
Amazon Simple Queue Service (Amazon SQS) queue
AWS Lambda
The relative benefits or each one are up to you but don't poll S3 for changes. Use one of these to be notified of the changes. You can decide to get notices for just new objects or deleted object.
Related
There is a use case I'm working on and I'm not quite sure how it can be solved. The main goal is to upload an image from a react native app to an Amazon S3 bucket using an AWS Lambda function (API Gateway) in order to use Amazon Rekognition service with another Amazon S3 image depending on some values sent to the lambda.
Since the image could be too large I have to use presigned URLs, which means that i make a request to the lambda to get a presigned S3 url to the client so that the client uploads the image to the bucket straight away. But then, how can i use face Rekognition service within the AWS Lambda?
I know i can trigger a lambda after an S3 upload, so i could do the face Rekognition request right after the user makes the http request with the presigned URL, but how can i get face Rekognition service response from that triggered lambda to the original user?
I've thought about SNS, but sending some text message to the user after an image upload instead of a message in the app seems odd.
Thank you in advance and apologies for the long read
You're on the right track with SNS, maybe not with the service, but with the principal.
This is a problem of asynchronous handling of requests and how you can subsequently inform the user of the server's decision. To start, you're async process will need to store the result of the facial recognition somewhere, if you're already using a database (SQL or NoSQL), that would seem to be the place to do this.
Then you have to get the information to the user. Since your user is running a mobile application, there are only two ways of doing this. Either the user will have to poll the back-end service in order to retrieve the result of the async process, or your back-end will need to push the result to the device. Polling the service is straightforward and is usable depending on the load you expect from your application and the duration of the asynchronous process. You can also use long polling to reduce the number of requests, but this doesn't fix the issue (too many users spamming your service waiting for the result) itself.
If you want to notify the users, you will have to create a notification mechanism that is not based on polling a service. You could for example make use of WebSockets, configure your devices to have an MQTT connection (e.g., with AWS IoT) or use another cloud-based notification service that allows you to push messages to the device. You also do not have to include all the information in the message you push to your devices. The pushed message can be a trigger for the device to retrieve the result from the back-end service e.g., using an HTTP API.
A user has created photo editing software and hosted it on EC2. The software accepts requests from the user about the photo format and resolution and sends a message to S3 to enhance the picture accordingly. Which of the below mentioned AWS services will help make a scalable software with the AWS infrastructure in this scenario?
A. AWS Simple Queue Service
B. AWS Simple Notification Service
C. AWS Glacier
D. AWS Elastic Transcoder
I think it should be D AWS Elastic Transcoder. What do u think?
Amazon Simple Queue Service (SQS. is a fast, reliable, scalable, and fully managed message queuing service. SQS provides a simple and cost-effective way to decouple the components of an application. The user can configure SQS, which will decouple the call between the EC2 application and S3. Thus, the application does not keep waiting for S3 to provide the data.
Glacier is for cold storage, Transcoder is sorely for video, SNS is
for notification, hence only SQS could help in processing fragments by
fragments information for the application. So the answer is A (AWS SQS)
You should use the AWS Elastic Transcoder with AWS Lambda + SQS. So whenever the server has any request from a user it will transfer the payload to SQS and SQS will trigger the Lambda. Now Lambda will do all business logic with AWS Elastic Transcoder. In this way, it can handle lots of traffic using SQL and Lambda. You can manage the Lambda thread and SQS queue pool.
I created a custom app that automatically uploads logs to s3.
Is there a way to push those logs to cloudwatch from s3 for analysis and alerting?
I'm aware that I can use a cloudwatch agent to push directly to cloudwatch from the app but there are complications involved in that option.
Thank you!
You could probably use Cloudwatch Events to listen to S3 changes. Not sure about if you can get the data from the S3 file, or just a trigger saying that a new log has been added.
You could also use S3 event notifications (https://docs.aws.amazon.com/AmazonS3/latest/dev/NotificationHowTo.html) connected either to a lambda or SQS, and from there create the logs to Cloudwatch. (similar to what was suggested by #marcin)
A better solution, but one that is a bit beyond the scope of the question, would be to send your logs through Kinesis Firehose and from there add the Cloudwatch and S3 logs.
I'm not aware of any out-of-the-box mechanism for that provided by AWS. But I think it could be relatively easy to develop.
Namely, you can create S3 notification for a PUT of a new log file from your app to S3. The event would trigger a lambda function. The function would get the file and using AWS SDK, e.g. boto3's put_log_events, it would send the log events to CloudWatch logs.
i want to pass trigger to an ecs instance when a file is uploaded to a bucket in s3 and process the uploaded file. so i need to get the bucket and file name into the ecs container.
the ecs instance is not already running. but started when the event occurs
I want to pass trigger an ECS instance when a file is uploaded to a
bucket in s3 and process the uploaded file
First thing, Environment variable load at the boot time of application while the event is not known at the start of application.
So the best way to handle this is SNS or SQS notification on s3 put event. You need
Put the file on S3
Event notification sent to SNS (data enters S3, notification of new data is sent to SNS)
SNS will trigger HTTP endpoint of your ECS container ( I assume that you already expose endpoint to process SNS topic.
Get the Name of the object and S3 bucket Name from SNS topic.
You can also use SQS with SNS but HTTP endpoint seems good,A high-level architecture will look like
Or details diagram
Is there a way by which I can get notified when a upload is completed in S3 Bucket? The requirement is that I need to provide link to users after uploading of a video is complete in the bucket. By default now I provide link after 30 minutes of start of video, whether video takes 5 minutes to upload or 40 minutes. So is there any way like any API that provides information that the upload has been completed?
Notifications can be triggered in Amazon S3 when any of the following occur:
s3:ObjectCreated:*
s3:ObjectCreated:Put
s3:ObjectCreated:Post
s3:ObjectCreated:Copy
s3:ObjectCreated:CompleteMultipartUpload
s3:ObjectRemoved:*
s3:ObjectRemoved:Delete
s3:ObjectRemoved:DeleteMarkerCreated
s3:ReducedRedundancyLostObject
Notifications can be sent via three destinations:
Amazon Simple Notification Service (SNS), which in-turn can send notifications via email, HTTP/S endpoint, SMS, mobile push notification
Amazon Simple Queueing Service (SQS)
Amazon Lambda (not currently available in all regions)
See: Configuring Amazon S3 Event Notifications
The most appropriate choice depends on your programming preference and how your app is written:
Use SNS to push to an HTTP endpoint to trigger some code in your app
Write some code to periodically check an SQS queue
Write a Lambda function in Node.js or Java
Once triggered, your code would then need to identify who uploaded the video, retrieve their user details, then send them an email notification. This would be easiest if you control the key (filename) of the object being uploaded, since this will assist in determining the user to notify.
You can use Amazon Lambda to post a message to Amazon SNS (or notify you any other way) when a file is uploaded to S3.
Setup an S3 trigger to your Lambda function. See this tutorial: http://docs.aws.amazon.com/lambda/latest/dg/walkthrough-s3-events-adminuser.html
Inside your Lambda function, send out your notification. You can use SNS, SES, SQS, etc.
There is no direct method that can tell that whether the upload is complete or not in S3 bucket. You can do a simple thing which I have followed after lot of research and it is working correctly.
Follow this link and read the size of file after every 30 seconds or so as per your requirement when the file size has not changed for two simultaneous readings once again check the size for surety because it might be due to network congestion that size might not have changed for two simultaneous readings.