For a while, both Parsoid/JS and Parsoid/PHP will be enabled in production. The original plan was to do the switch by wiki where all services on that wiki will be switched over. But, @Pchelolo thinks that is a risky all-or-nothing strategy. He advocates for a strategy where we switch over client services at different points as different services are tested and can be switched over or reverted on an individual basis.
This requires that for every wiki, RESTBase stores content of both Parsoid/PHP and Parsoid/JS at the same time, effectively doubling storage from the time Parsoid/PHP goes live to the time Parsoid/JS is decommissioned.
This task is to track the work required for ensuring RESTBase can store Parsoid/PHP content alongwith parsoid/JS content.