To better distribute the memory allocating to indexing, the IndexingMemoryController periodically checks the different shard for their last indexing activity. If no activity has happened for a while, the controller marks the shards as in active and allocated it's memory buffer budget (but a small minimal budget) to other active shards. The recently added synced flush feature (#11179, #11336) uses this inactivity trigger to attempt as a trigger to attempt adding a sync id marker (which will speed up future recoveries).
We wait for 30m before declaring a shard inactive. However, these days the operation just requires a refresh and is light. We can be stricter (and 5m) increase the chance a synced flush will be triggered.
Closes#11479
26d71fe00e