@Test
  public void testBug35048() {
    DiskRegionProperties p = new DiskRegionProperties();
    p.setMaxOplogSize(1000);
    p.setRegionName(getName() + counter);
    p.setDiskDirs(dirs);
    p.setOverflow(true);
    p.setSynchronous(false);
    p.setOverFlowCapacity(5);
    p.setRolling(true);
    byte[] val = new byte[50];
    region = DiskRegionHelperFactory.getAsyncOverFlowOnlyRegion(cache, p);
    for (int j = 1; j < 6; ++j) {
      region.put("" + j, val);
    }
    // This will overflow the first entry to disk. Its OplogKeyID will be now
    // positive & value in VM is null
    region.put("" + 6, val);
    // Do a get opeartion on entry which has been overflown to disk. The value
    // in VM is now not null, but its Oplog KeyID is positive
    region.get("" + 1);
    // Do a force roll
    region.forceRolling();
    // Do a get on entries starting from 2 to 6 & then 1. This will ensure that
    // the entry 1 gets evicted
    // from memory but is not written to disk as its Oplog KeyId is positive.
    // then do a get operation on entry with key as 1. The vale should be
    // correctly retrieved from
    // Htree implying the roller has rolled the entry correctly
    try {
      region.get("" + 2);
      region.get("" + 3);
      region.get("" + 4);
      region.get("" + 5);
      region.get("" + 6);
      try {
        region.get("" + 1);
      } catch (Exception e) {
        logWriter.severe("Exception occurred  ", e);
        fail(
            "Failed to retrieve value from disk as the Oplog has been rolled but entry still references the Oplog.");
      }

    } catch (Exception e) {
      logWriter.severe("Exception occurred  ", e);
      fail("Test failed because  of unexpected exception");
    }

    // Now force roll the oplog so that the data exists in the Oplog which has
    // been deleted

  }
Tests the bug where a get operation on an evicted entry fails to get value as the oplog is
deleted by the roller, but the entry was not rolled.
geode-core/src/integrationTest/java/org/apache/geode/internal/cache/ConcurrentRegionOperationsJUnitTest.java