Here's a unittest demonstrating the use case :
public class TwoCellUpdatesTest {
@Test
public void testCellUpdates() throws Exception {
Configuration configuration = HBaseConfiguration.create();
HBaseTestingUtility hBaseTestingUtility = new
HBaseTestingUtility(configuration);
hBaseTestingUtility.startMiniCluster(1);
HBaseAdmin admin = new HBaseAdmin(configuration);
HTableDescriptor tableDescriptor = new
HTableDescriptor("TestTable");
byte[] CF = Bytes.toBytes("CF");
tableDescriptor.addFamily(new HColumnDescriptor(CF,
HConstants.ALL_VERSIONS, "none", false, true, HConstants.FOREVER,
HColumnDescriptor.DEFAULT_BLOOMFILTER));
admin.createTable(tableDescriptor);
LocalHTable hTable = new LocalHTable(configuration, "TestTable");
// Write a column with values at timestamp 1, 2 and 3
byte[] row = Bytes.toBytes("myRow");
byte[] qualifier = Bytes.toBytes("myCol");
Put put = new Put(row);
put.add(CF, qualifier, 1L, Bytes.toBytes("AAA"));
hTable.put(put);
put = new Put(row);
put.add(CF, qualifier, 2L, Bytes.toBytes("BBB"));
hTable.put(put);
put = new Put(row);
put.add(CF, qualifier, 3L, Bytes.toBytes("EEE"));
hTable.put(put);
Get get = new Get(row);
get.addColumn(CF, qualifier);
get.setMaxVersions();
// Check that the column indeed has the right values at timestamps 1
and 2
Result result = hTable.get(get);
NavigableMap<Long,byte[]> navigableMap =
result.getMap().get(CF).get(qualifier);
assertEquals("AAA", Bytes.toString(navigableMap.get(1L)));
assertEquals("BBB", Bytes.toString(navigableMap.get(2L)));
// Let major compaction do its work
admin.flush("TestTable");
admin.majorCompact("TestTable");
Thread.sleep(6000);
// Update the value at timestamp 1
put = new Put(row);
put.add(CF, qualifier, 1L, Bytes.toBytes("CCC"));
hTable.put(put);
// Triggering a major compaction here would make the test succeed
// admin.flush("TestTable");
// admin.majorCompact("TestTable");
// Thread.sleep(6000);
// Update the value at timestamp 2
put = new Put(row);
put.add(CF, qualifier, 2L, Bytes.toBytes("DDD"));
hTable.put(put);
// Let major compaction do its work
admin.flush("TestTable");
admin.majorCompact("TestTable");
Thread.sleep(6000);
// Check that the values at timestamp 2 and 1 got updated
result = hTable.get(get);
navigableMap = result.getMap().get(CF).get(qualifier);
assertEquals("DDD", Bytes.toString(navigableMap.get(2L)));
assertEquals("CCC", Bytes.toString(navigableMap.get(1L)));
}
}
On Fri, Aug 20, 2010 at 7:46 PM, Jean-Daniel Cryans <[email protected]>wrote:
> I think that this is stretching the usage of timestamps... but would
> you be able to write a small unit test that demonstrates it? Also did
> you try it on both 0.20 and 0.89?
>
> Thx,
>
> J-D
>
> On Fri, Aug 20, 2010 at 6:18 AM, Evert Arckens <[email protected]>
> wrote:
> > Hi,
> >
> > I have a scenario of which I'm not sure if it is just another example of
> > issue HBASE-1485, or if it is another but related issue :
> >
> > Write 3 cells of a column, at timestamp 1, 2 and 3.
> > Then update the cells at timestamp 1 and 2 (more or less at the same
> > moment).
> >
> > Result is that the update of the cell at timestamp 1 gets lost.
> > If I would perform a major compaction between both updates, the update on
> > timestamp 1 wouldn't get lost.
> >
> > The reason I'm not sure if it is exactly the same issue as HBASE-1485 is
> > because that one just talks about updates on 1 cell, not on a combination
> > updates on 2 cells at different timestamps.
> >
> > Regards,
> > Evert Arckens.
> >
>
