Moodle Universal Cache (MUC)
Caching has proven to be one of the most efficient performance optimization techniques, and Moodle is no exception.
Moodle contains a powerful caching framework called MUC, which allows certain functions to take advantage of different configured caching services (docs.moodle.org/en/Caching).
Before we look at how MUC works, let’s explore some basic concepts: cache types (modes), cache stores, and cache definitions. The following diagram shows all three concepts and how they work together in MUC:
Figure 15.6 – Moodle Universal Cache