@TestOnly
  public static void enableFileInfoCacheForTest(
      int globalCompactionFileInfoCacheSize, int globalCompactionRoughFileInfoCacheSize) {
    globalFileInfoCacheEnabled = true;
    globalRoughInfoCacheForCompaction =
        Collections.synchronizedMap(new LRUMap<>(globalCompactionFileInfoCacheSize));
    globalFileInfoCacheForFailedCompaction =
        Collections.synchronizedMap(new LRUMap<>(globalCompactionRoughFileInfoCacheSize));
  }
The size of global compaction estimation rough file info cahce.
iotdb-core/datanode/src/main/java/org/apache/iotdb/db/storageengine/dataregion/compaction/selector/estimator/AbstractCompactionEstimator.java