Major Description
The method MemStoreFlusher#checkStoreFileCount is called from flushRegion. flushRegion is called by MemStoreFlusher#run thread. If the checkStoreFileCount finds too many store files, it'll stick around waiting on a compaction to happen. While its hanging, the MemStoreFlusher#run is held up. No other region can flush. Meantime WALs will be rolling and memory will be accumulating writes.