HBase Put with timestamp does not work

Question

I wrote a simple test program to insert a row. The only different point from normal HBase Put example programs is that a Put instance and its KeyValue instances are created with a timestamp.

The expected behavior is that a row is inserted. However, in my HBase environment, no row is inserted.

Below is my test program.

import java.io.*;
import java.util.*;
import org.apache.hadoop.conf.*;
import org.apache.hadoop.hbase.*;
import org.apache.hadoop.hbase.client.*;
import org.apache.hadoop.hbase.util.*;

public class Test
{
    // Names of table, family, qualifier and row ID.
    private static final byte[] TABLE     = Bytes.toBytes("test-table");
    private static final byte[] FAMILY    = Bytes.toBytes("test-family");
    private static final byte[] QUALIFIER = Bytes.toBytes("test-qualifier");
    private static final byte[] ROWID     = Bytes.toBytes("test-rowid");

    /**
     * The entry point of this program.
     *
     * <p>
     * This program assumes that there already exists an HBase
     * table named "test-table" with a column family named
     * "test-family". To create an HBase table satisfying these
     * conditions, type the following at the hbase shell prompt.
     * </p>
     *
     * <pre>
     * hbase&gt; create 'test-table', 'test-family'
     * </pre>
     *
     * <p>
     * This program inserts a row whose row ID is "test-rowid"
     * with a column named "test-family:test-qualifier". The
     * value of the column is the string expression of
     * <code>new Date()</code>.
     * </p>
     */
    public static void main(String[] args) throws Exception
    {
        // Get the table.
        Configuration conf = HBaseConfiguration.create();
        HTable table = new HTable(conf, TABLE);

        // Prepare data to put.
        byte[] value = Bytes.toBytes(new Date().toString());
        Put put = new Put(ROWID);
        put.add(FAMILY, QUALIFIER, value);

        // Clone Put with a timestamp.
        put = clone(put, 10);

        // Put the data.
        table.put(put);

        // Read back the data.
        Get get = new Get(ROWID);
        Result result = table.get(get);

        // Dump the read data.
        System.out.println("DATA = " + result.toString());
    }

    /**
     * Clone the given Put instance with the given timestamp.
     */
    private static Put clone(Put a, long timestamp) throws IOException
    {
        // Create a Put instance with the specified timestamp.
        Put b = new Put(a.getRow(), timestamp);

        Map<byte[], List<KeyValue>> kvs = a.getFamilyMap();

        // Copy KeyValue's from the source Put (a) to
        // the cloned Put (b). Note the given timestamp
        // is used for each new KeyValue instance.
        for (List<KeyValue> kvl : kvs.values())
        {
            for (KeyValue kv : kvl)
            {
                b.add(new KeyValue(
                    kv.getRow(),
                    kv.getFamily(),
                    kv.getQualifier(),
                    timestamp,
                    kv.getValue()));
            }
        }

        return b;
    }
}

The console output generated by this program is as follows.

DATA = keyvalues=NONE

And "scan" at the hbase shell says "0 row(s)".

hbase(main):011:0> scan 'test-table'
ROW                                              COLUMN+CELL
0 row(s) in 0.0080 seconds

Commenting out the code line to clone a Put instance like below,

        // Clone Put with a timestamp.
        //put = clone(put, 10);

that is, using a Put instance created with no timestamp argument changes the behavior of the program. In this case, the console output shows the inserted value,

DATA = keyvalues={test-rowid/test-family:test-qualifier/1344594210281/Put/vlen=28}

and "scan" shows the inserted row.

hbase(main):012:0> scan 'test-table'
ROW                                              COLUMN+CELL
 test-rowid                                      column=test-family:test-qualifier, timestamp=1344594210281, value=Fri Aug 10 19:23:30 JST 2012
1 row(s) in 0.0110 seconds

The logic to clone a Put instance with a timestamp used in my test program is an excerpt from an open source project which is known to work. So, I guess that the root cause of this problem exists in my HBase environment, but I have no clue. My investigation may be insufficient, but I have not seen any error in HBase logs yet.

Could anyone give me any light on this problem, please?

Have you try to create a new put with a timestamp instead of cloning the existing one? Also you can specify the timestamp in the add method of the Put class. Just to see if the problem persists, if so it could mean that the problem is in your environment as you suspect. — Diego

Jaison Thomas Jaison Thomas · Accepted Answer · 2012-08-11T04:11:00

Timestamp column family and column name constitutes a combined key. Here time stamp is UNIX timestamp.

HBase Put with timestamp does not work

3 Answers