Some plugins utilize global per-feed content hooks which either modify fetched feed XML data (i.e. fixing broken XML) or even generate it entirely, for tt-rss to process, for websites that don’t actually provide RSS feeds.
While having this ability available for plugins is valuable there are several downsides:
This entirely bypasses rate-limiting and article duplicate
checking done during normal feed update process. A badly written plugin
using HOOK_FETCH_FEED may cause your tt-rss feed to keep
updating feeds indefinitely, processing all articles every time, causing
unnecessary CPU load on your server.
If you have full text content plugins enabled, this may cause excessive load on origin server, because your tt-rss instance is going to scrape site content for every provided article on every feed update.
This may result in your tt-rss instance being banned by origin servers for causing excessive load and/or your VDS being suspended for suspected bad behavior.
Additionally, tt-rss being blacklisted by feed publishers may negatively affect other users.
We recommend not using such plugins unless you have a strong need for them. If you do use them, at least don’t enable them for all feeds.
See also: