To allow customers to build large Board Hierarchies (with > 500 Boards) we allow you to build a Board Hierarchy within Batch Apex or other Asynchronous executions. Hierarchy Rollups do not run in asynchronous execution which makes these operations much faster with reduced execution overhead.
As Board Hierarchy Roll Ups are not run when each Board is created it is therefore critical to run the Board Hierarchy Rollup Batch once the Board structure has been built. This is exposed in Apex via the TaskfeedApexAPI class.
TaskfeedApexAPI.execBoardHierarchyRollupBatch(Set<String> ultimateParentIds, Integer batchSize)
UltimateParentIds is a set of Board Ids for the Ultimate Parent which is the Board expected to be at the very top of the Hierarchy. This will process each Board Hierarchy in batches provided by the batchSize attribute (Recommended providing batchSize of 1 to ensure each Batch has sufficient processing limits available).