We are exposing parsoid endpoints from a number of MediaWiki REST endpoints, like `/w/rest.php/{domain}/v3/page/html/{title}` and `/w/rest.php/v1/page/{title}/html`. These currently are marked with a low TTL, because we have no mechanism in place to actively purge them. We need such a mechanism before we rely on these endpoints to replace the parsoid endpoints exposed by RESTbase, namely `/api/rest_v1/page/html/{title}`.
Currently, the endpoints exposed by RESTbase rely on puring implemented in the parsoid.js module, which emits events whenever it updates the stored/pregenerated copy of the parsoid output.
In a world without RESTbase, we will need to extend the mechanism we are currently using to purge page view URLs to also cover the HTML endpoints.
NOTE: we can't use the new mechanism for the RESTbase URLs while RESTbase is still storing content, because it would create a race condition.
See also {T308424}
== Impact/Risk Assessment ==
Number of external queries that would be affected by (not) currectly puring:
* /w/rest.php/v1/page/{title}/html: less than one per minute. No gateway. This endpoint is not advertized anywhere
* /w/rest.php/{domain}/v3/page/html: less than one per month. No gateway. This endpoint is not advertized anywhere.
* /api/rest_v1/page/html: more than 100 per second.
Top users of /api/rest_v1/page/html:
{F37629395}
(numbers are per day, samled 1/128)