Rich Media parsing was previously handled on-demand with a 2 second HTTP request timeout and retained only in Cachex. Every time a Pleroma instance is restarted it will have to request and parse the data for each status with a URL detected. When fetching a batch of statuses they were processed in parallel to attempt to keep the maximum latency at 2 seconds, but often resulted in a timeline appearing to hang during loading due to a URL that could not be successfully reached. URLs which had images links that expire (Amazon AWS) were parsed and inserted with a TTL to ensure the image link would not break.
Rich Media data is now cached in the database and fetched asynchronously. Cachex is used as a read-through cache. When the data becomes available we stream an update to the clients. If the result is returned quickly the experience is almost seamless. Activities were already processed for their Rich Media data during ingestion to warm the cache, so users should not normally encounter the asynchronous loading of the Rich Media data.
Implementation notes:
- The async worker is a Task with a globally unique process name to prevent duplicate processing of the same URL
- The Task will attempt to fetch the data 3 times with increasing sleep time between attempts
- The HTTP request obeys the default HTTP request timeout value instead of 2 seconds
- URLs that cannot be successfully parsed due to an unexpected error receives a negative cache entry for 15 minutes
- URLs that fail with an expected error will receive a negative cache with no TTL
- Activities that have no detected URLs insert a nil value in the Cachex :scrubber_cache so we do not repeat parsing the object content with Floki every time the activity is rendered
- Expiring image URLs are handled with an Oban job
- There is no automatic cleanup of the Rich Media data in the database, but it is safe to delete at any time
- The post draft/preview feature makes the URL processing synchronous so the rendered post preview will have an accurate rendering
Overall performance of timelines and creating new posts which contain URLs is greatly improved.
OTP builds to 1.15
Changelog entry
Ensure policies are fully loaded
Fix :warn
use main branch for linkify
Fix warn in tests
Migrations for phoenix 1.17
Revert "Migrations for phoenix 1.17"
This reverts commit 6a3b2f15b7.
Oban upgrade
Add default empty whitelist
mix format
limit test to amd64
OTP 26 tests for 1.15
use OTP_VERSION tag
baka
just 1.15
Massive deps update
Update locale, deps
Mix format
shell????
multiline???
?
max cases 1
use assert_recieve
don't put_env in async tests
don't async conn/fs tests
mix format
FIx some uploader issues
Fix tests
This shouldn't be too expensive, since the connections are pooled,
but it should save us some bandwidth since we won't fetch non-html
files and files that are too large for us to process (especially
since you can't cancel a request without closing the connection
with HTTP1).
