@Test
  public void testScanAndSyncFlush() throws Exception {
    this.region = TEST_UTIL.createLocalHRegion(TESTTABLEDESC, null, null);
    Table hri = new RegionAsTable(region);
    try {
      LOG.info("Added: " + HTestConst.addContent(hri, Bytes.toString(HConstants.CATALOG_FAMILY),
        Bytes.toString(HConstants.REGIONINFO_QUALIFIER)));
      int count = count(hri, -1, false);
      assertEquals(count, count(hri, 100, false)); // do a sync flush.
    } catch (Exception e) {
      LOG.error("Failed", e);
      throw e;
    } finally {
      HBaseTestingUtil.closeRegionAndWAL(this.region);
    }
  }
Tests to do a sync flush during the middle of a scan. This is testing the StoreScanner update
readers code essentially. This is not highly concurrent, since its all 1 thread. HBase-910.
hbase-server/src/test/java/org/apache/hadoop/hbase/regionserver/TestScanner.java