private void stopPrefetch(ScanController controller) {
    if (LOG.isDebugEnabled()) {
      LOG.debug(
        "{} stop prefetching when scanning {} as the cache size {}"
          + " is greater than the maxCacheSize {}",
        String.format("0x%x", System.identityHashCode(this)), tableName, cacheSize, maxCacheSize);
    }
    resumer = controller.suspend();
  }
The {@link ResultScanner} implementation for {@link RawAsyncTableImpl}. It will fetch data
automatically in background and cache it in memory. Typically, the {@link #maxCacheSize} will be
{@code 2 * scan.getMaxResultSize()}.
hbase-client/src/main/java/org/apache/hadoop/hbase/client/AsyncTableResultScanner.java