A system and method for maintaining a comprehensive catalog of metadata records that describes hierarchical file data held in one or more file systems includes a Modular Change Processor (MCP) that captures event notifications pertaining to contents of affected directories within the file systems, coalesces the translated event notifications, and transmits to the catalog, instructions to mark metadata corresponding to the affected directories as ‘out-of-sync’. An Enumerator Computer (EC) receives from the catalog, identities of directories having metadata marked ‘out-of-sync’; receives from the file systems, updated contents of the ‘out-of-sync’ directories; generates replacement metadata for the updated contents; and sends the replacement metadata to the catalog, optionally with instructions to replace the metadata marked ‘out-of-sync’ with corresponding replacement metadata and to mark the replacement metadata as ‘in-sync’.