@Test
  public void testRetryGetNamedBlobFromDiffDcs() throws Exception {
    dataSourceFactory.setLocalDatacenter(localDatacenter);
    dataSourceFactory.triggerEmptyResultSetForLocalDataCenter(datacenters);
    NamedBlobRecord namedBlobRecord = namedBlobDb.get(account.getName(), container.getName(), "blobName").get();
    assertEquals("Blob Id is not matched with the record", id, namedBlobRecord.getBlobId());
    NamedBlobRecord namedBlobRecord1 = namedBlobDb.get(account.getName(), container.getName(), "blobName").get();
    assertEquals("Blob Id is not matched with the record", id, namedBlobRecord1.getBlobId());
    dataSourceFactory.triggerEmptyResultSetForAllDataCenters(datacenters);
    checkErrorCode(() -> namedBlobDb.get(account.getName(), container.getName(), "blobName"), RestServiceErrorCode.NotFound);
  }
Tests for {@link MySqlNamedBlobDb} that require a mocked data source.
ambry-named-mysql/src/test/java/com/github/ambry/named/MySqlNamedBlobDbTest.java