feat(server): library refresh go brrr

[etnoy]

This PR significantly improves library scanning performance. Wherever suitable, we are doing jobs in batches, and many looped database interactions are replaced with SQL queries.

User testimonials
"@etnoy what on earth have you done. I tried your PR and it finished the scan for 1M assets in 37 seconds down from 728s on main. It takes 188s just to finish queuing on main" -- @mertalev

Changes made

• When crawling a library: Don't call stat() on the files when importing, instead put a placeholder date (9999-12-31) that will be overwritten by metadata extraction. All dates after year 9000 are ignored in the timeline
• When importing new library files: Crawl 10k files per batch and then insert each batch in a single SQL query instead adding them individually
• When checking asset filenames against import paths and exclusion patterns: Do this directly in SQL which is much faster
• When a library is deleted, hide all its assets first. Otherwise, they'll linger until the asset deletion job catches up which can take days for >1M libraries

Plus several minor cleanups and performance enhancements.

The performance improvements are at least an order of magnitude in library scanning.

Benchmark 1
A library scan with 22k items where nothing has changed since the last scan used to take 1m 22s, now it's below 10 seconds, an improvement of 87 percent!

Benchmark 2
A clean library import with 19k items takes 1m40s in main and 7 seconds in this PR.
NOTE: this benchmark is only the library service scan and does not include the metadata extraction. Also, some fs calls have been migrated from the library service to the metadata service, although this should only have a minor impact on overall scan performance

Benchmark 3
Importing a library with >5M assets.

• Time to 1M imported (without metadata extraction): 6m50s.

No need to compare to main, you know it's fast!

Benchmark 4
Importing a library of 527041 files took 1m58s (without metadata extraction) in this PR.
No need to compare to main, you know it's fast!

Bonus:

• Greatly improved log messages related to library scans.
  This scan imports all new files:
  

This is an "idle scan", where a refresh finds no changes:

• More e2e tests for handling when offline files go back online, leading to one major bug fixed

Future work:

• Crawl for XMP sidecars instead of queuing a sidecar discovery for each asset

Final note:
This PR allowed me to hit a milestone of 10M assets in a single Immich instance, likely a world-first. This does require max-old-space-size=8096, but that's to be expected anyway

[mertalev]

Nice start! I think there are still a lot of untapped potential improvements here.

[mertalev]

The update to fileCreatedAt, fileModifiedAt and originalFileName is unnecessary and can be handled in metadata extraction since this will be queued anyway. This makes the batched update for isOffline and deletedAt simpler since there'll be no values that are unique to each asset.

[etnoy]

Thanks for your comments @mertalev ! I'll first attempt to do the import path and exclusion pattern checks in SQL and then move to your suggestions

[etnoy]

The update to fileCreatedAt, fileModifiedAt and originalFileName is unnecessary and can be handled in metadata extraction since this will be queued anyway. This makes the batched update for isOffline and deletedAt simpler since there'll be no values that are unique to each asset.

Never thought of that, I've implemented your suggestion. I'm also considering changing the initial import code to ignore file mtime, this allows us to not do any file system calls except for the crawl. Metadata extraction will have to do the heavy lifting instead

[mertalev]

The update to fileCreatedAt, fileModifiedAt and originalFileName is unnecessary and can be handled in metadata extraction since this will be queued anyway. This makes the batched update for isOffline and deletedAt simpler since there'll be no values that are unique to each asset.

Never thought of that, I've implemented your suggestion. I'm also considering changing the initial import code to ignore file mtime, this allows us to not do any file system calls except for the crawl. Metadata extraction will have to do the heavy lifting instead

Would that mean you queue them for metadata extraction even if they're unchanged? You can test it but I think it'd be more overhead than the stat calls.

Edit: also if you do this with the source set to upload, it would definitely be worse because it would queue a bunch of other things after metadata extraction.

[etnoy]

The update to fileCreatedAt, fileModifiedAt and originalFileName is unnecessary and can be handled in metadata extraction since this will be queued anyway. This makes the batched update for isOffline and deletedAt simpler since there'll be no values that are unique to each asset.

Never thought of that, I've implemented your suggestion. I'm also considering changing the initial import code to ignore file mtime, this allows us to not do any file system calls except for the crawl. Metadata extraction will have to do the heavy lifting instead

Would that mean you queue them for metadata extraction even if they're unchanged? You can test it but I think it'd be more overhead than the stat calls.

Edit: also if you do this with the source set to upload, it would definitely be worse because it would queue a bunch of other things after metadata extraction.

I was referring to new imports, files that are new to immich. I hoped to improve the ingest performance by removing the stat call. After testing, there are two issues:

• assetRepository.create requires mtime, which we can only get from stat. We could work around that by setting it to new Date(), but ideally it should be undefined
• We still check for the existence of a sidecar, and this complicates things

If we can mitigate the two issues above, I can rewrite the library import feature and do that in batches as well!

[mertalev]

I don't see why fileModifiedAt needs a non-null constraint in the DB. Might just be an oversight that didn't matter because it didn't affect our usage. I think you can change the asset entity and generate a migration to remove that constraint.

For sidecar files, maybe you could add.xmp to the glob filter and enable the option to make the files come in sorted order? That way you could make sure they're in the same batch.

[etnoy]

I don't see why fileModifiedAt needs a non-null constraint in the DB. Might just be an oversight that didn't matter because it didn't affect our usage. I think you can change the asset entity and generate a migration to remove that constraint.

For sidecar files, maybe you could add.xmp to the glob filter and enable the option to make the files come in sorted order? That way you could make sure they're in the same batch.

I might just put new Date() in at the moment to keep the PR somewhat constrained.

Regarding sidecars, I have thought about that, problem right now is that we're batching the crawled files in batches of 10k. It might be hard to do get that working alright. Maybe I'll just queue a sidecar discovery for every imported asset for now

[alextran1502]

You call on merging this one @mertalev

[zackpollard]

You call on merging this one @mertalev

If it's ready for final review I would like to take a look at it too before it is merged, I can take a look tomorrow morning.

[etnoy]

You call on merging this one @mertalev

If it's ready for final review I would like to take a look at it too before it is merged, I can take a look tomorrow morning.

Thanks, I'd apprecate it!

[mertalev]

@etnoy I made a few changes, let me know if there's anything that seems off.

[etnoy]

@etnoy I made a few changes, let me know if there's anything that seems off.

I had a look and it's a big improvement, thanks for helping me clean this up

[zackpollard]

Didn't get to this today sorry, on my list for tomorrow 😅

[zackpollard]

LGTM, nice work. You have some failing unit tests after the latest changes, but it's good to go after those are fixed I think

[etnoy]

@zackpollard good to go now that the release is done?