Preview attachments on external storage are not stored in the db activestorrage

[johansmitsnl]

Steps to reproduce

• Install a S3 backend according the guide
• Upload a file

Expected behavior

Store the variant also in the DB so it does not need a extra roundtrip to the S3 backend because it takes a lot of extra time and a payed hit on the S3 API.

Actual behavior

When a variant file is displayed with image_tag @medium.object.variant(resize: "100x100") it creates a temporary redirect link. When the link is accessed it checks in de backend if the file exists it redirect to this if not it creates one (expected) for the first time. Why does it needs to check the second time the backend again to verify if the file is there?

System configuration

Rails version: 5.2.0

Ruby version: 2.5.1

See the S3 extra time of 248ms which can be saved by storing also the variant in the DB.

Started GET "/rails/active_storage/representations/eyJfcmFpbHMiOnsibWVzc2FnZSI6IkJBaHBDUT09IiwiZXhwIjpudWxsLCJwdXIiOiJibG9iX2lkIn19--7bedf6cf1d85f143fa1cf3114ea2bc1d07ebfd5d/eyJfcmFpbHMiOnsibWVzc2FnZSI6IkJBaDdCam9MY21WemFYcGxTU0lNTVRBd2VERXdNQVk2QmtWVSIsImV4cCI6bnVsbCwicHVyIjoidmFyaWF0aW9uIn19--858057ffe36ceadc4c3ef7a7e88828f422043320/01508_paradise_1920x1080.jpg" for ::1 at 2018-04-12 18:13:14 +0200
Processing by ActiveStorage::RepresentationsController#show as JPEG
  Parameters: {"signed_blob_id"=>"eyJfcmFpbHMiOnsibWVzc2FnZSI6IkJBaHBDUT09IiwiZXhwIjpudWxsLCJwdXIiOiJibG9iX2lkIn19--7bedf6cf1d85f143fa1cf3114ea2bc1d07ebfd5d", "variation_key"=>"eyJfcmFpbHMiOnsibWVzc2FnZSI6IkJBaDdCam9MY21WemFYcGxTU0lNTVRBd2VERXdNQVk2QmtWVSIsImV4cCI6bnVsbCwicHVyIjoidmFyaWF0aW9uIn19--858057ffe36ceadc4c3ef7a7e88828f422043320", "filename"=>"01508_paradise_1920x1080"}
  ActiveStorage::Blob Load (0.3ms)  SELECT  "active_storage_blobs".* FROM "active_storage_blobs" WHERE "active_storage_blobs"."id" = ? LIMIT ?  [["id", 4], ["LIMIT", 1]]
  ↳ vendor/bundle/ruby/2.5.0/gems/activerecord-5.2.0/lib/active_record/log_subscriber.rb:98
  S3 Storage (248.4ms) Checked if file exists at key: variants/3FKExTkgi1Y2TKQVxauWFL7Q/4ee1aeed96ebbe10c358175ed0e35ee3865e7ff1f5fdac3eb240725f48e4cb91 (yes)
  S3 Storage (4.2ms) Generated URL for file at key: variants/3FKExTkgi1Y2TKQVxauWFL7Q/4ee1aeed96ebbe10c358175ed0e35ee3865e7ff1f5fdac3eb240725f48e4cb91 (https://rails-test-js.s3.eu-central-1.amazonaws.com/variants/3FKExTkgi1Y2TKQVxauWFL7Q/4ee1aeed96ebbe10c358175ed0e35ee3865e7ff1f5fdac3eb240725f48e4cb91?response-content-disposition=inline%3B%20filename%3D%2201508_paradise_1920x1080.jpg%22%3B%20filename%2A%3DUTF-8%27%2701508_paradise_1920x1080.jpg&response-content-type=image%2Fjpeg&X-Amz-Algorithm=AWS4-HMAC-SHA256&X-Amz-Credential=AKIAJEACUYOCFDPEQYCA%2F20180412%2Feu-central-1%2Fs3%2Faws4_request&X-Amz-Date=20180412T161315Z&X-Amz-Expires=300&X-Amz-SignedHeaders=host&X-Amz-Signature=8d0317910080b4513bc5fe96b8c17a78c7b847762718a9e6efbdbd49d61e4b1f)
Redirected to https://rails-test-js.s3.eu-central-1.amazonaws.com/variants/3FKExTkgi1Y2TKQVxauWFL7Q/4ee1aeed96ebbe10c358175ed0e35ee3865e7ff1f5fdac3eb240725f48e4cb91?response-content-disposition=inline%3B%20filename%3D%2201508_paradise_1920x1080.jpg%22%3B%20filename%2A%3DUTF-8%27%2701508_paradise_1920x1080.jpg&response-content-type=image%2Fjpeg&X-Amz-Algorithm=AWS4-HMAC-SHA256&X-Amz-Credential=AKIAJEACUYOCFDPEQYCA%2F20180412%2Feu-central-1%2Fs3%2Faws4_request&X-Amz-Date=20180412T161315Z&X-Amz-Expires=300&X-Amz-SignedHeaders=host&X-Amz-Signature=8d0317910080b4513bc5fe96b8c17a78c7b847762718a9e6efbdbd49d61e4b1f
Completed 302 Found in 257ms (ActiveRecord: 0.3ms)

[rails-bot]

This issue has been automatically marked as stale because it has not been commented on for at least three months.
The resources of the Rails team are limited, and so we are asking for your help.
If you can still reproduce this error on the 5-2-stable branch or on master, please reply with all of the information you have about it in order to keep the issue open.
Thank you for all your contributions.

[saiqulhaq]

which one is cheaper? hit amazon S3 or add more Kb in amazon RDS?

[johansmitsnl]

Depends on the traffic it gets on that specific thumbnail(s).
In speed the DB wins. In my usecase the same thumbnails are hit many (I mean many) times and each time it hits the S3 adding additional latency. The Kb cost or api hits are not a concern to me, the speed is.

[timdown]

The hundreds-of-milliseconds round trip to S3 makes variants unusable for my current project so is a big problem for me. I'd suggest a different approach in which a record of each variant created is stored in an Active Storage table (perhaps a new table) to eliminate the need to check on S3.

[rails-bot]

This issue has been automatically marked as stale because it has not been commented on for at least three months.
The resources of the Rails team are limited, and so we are asking for your help.
If you can still reproduce this error on the 5-2-stable branch or on master, please reply with all of the information you have about it in order to keep the issue open.
Thank you for all your contributions.

[johansmitsnl]

This is still an issue.

[timdown]

There is no new information. There is just the fact that this issue still exists and hasn't been fixed.

[rafaelfranca]

Thanks. Although as you can see 6 months have passed and this was not fixed yet. So, if you care to fix it I'd recommend you to do so. If not, next time the bot comment I'll close this since we can see this more as feature request than an issue.

[johansmitsnl]

@rafaelfranca do we agree it is a feature request and if so could it be labeled as one?

[rails-bot]

This issue has been automatically marked as stale because it has not been commented on for at least three months.
The resources of the Rails team are limited, and so we are asking for your help.
If you can still reproduce this error on the 5-2-stable branch or on master, please reply with all of the information you have about it in order to keep the issue open.
Thank you for all your contributions.