Fix thumbnails index

[jkolo]

Based on PR #1816

[matrixbot]

Can one of the admins verify this patch?

[matrixbot]

Can one of the admins verify this patch?

[matrixbot]

Can one of the admins verify this patch?

[r3k2]

I think im having this issue now.. #2442

[jkolo]

bump

[lukebarnard1]

So it turns out that if the bug is due to the constraint in the DB, it should also be affecting the pre-generated thumbnails, given that we pre-generate for both "scale" and "crop" methods.

OR it's possible that we never pre-generate images of the same size but using different methods, which is looking likely, given the default is:

- width: 32
  height: 32
  method: crop
- width: 96
  height: 96
  method: crop
- width: 320
  height: 240
  method: scale
- width: 640
  height: 480
  method: scale
- width: 800
  height: 600
  method: scale

[lukebarnard1]

Having added:

- width: 32
  height: 32
  method: scale

things seem to work without issue, so this is likely not the right fix.

Importantly, in local_media_cache_thumbnails we store actual thumbnail dimensions, which will vary for a given image using different methods. In remote_media_cache_thumbnails, we store the requested dimensions, which will not change for a given image using different methods, which means we can't insert a new entry.

So basically I think we only need to add the constraint to remote_media_cache_thumbnails. OR we can store the actual thumbnail sizes like we do for the local one but 🤷‍♂️.

[richvdh]

Does anybody remember what exactly this is trying to fix?

[richvdh]

looks like it is trying to fix #2182

[rubo77]

Please rebase!

also should you change the creation in

synapse/synapse/storage/schema/full_schemas/16/media_repository.sql

Line 26 in 53969e1

CREATE TABLE IF NOT EXISTS local_media_repository_thumbnails (

add thumbnail_method to the UNIQUE list

And does this really fix #2182 ? there is suggested another fix by @ananace: #2182 (comment)

ALTER TABLE remote_media_cache_thumbnails DROP CONSTRAINT remote_media_cache_thumbnails_media_origin_media_id_thumbna_key; CREATE INDEX remote_media_cache_thumbnails_media_origin_media_id_thumbna_key ON remote_media_cache_thumbnails (media_origin, media_id, thumbnail_width, thumbnail_height, thumbnail_type, thumbnail_method);

Can some admin take this over please? @jkolo isn't acitve siince months.

[richvdh]

I'm pretty sure this an incorrect change, and has bitrotted.