src/java/org/apache/cassandra/hadoop/ColumnFamilyRecordWriter.java
/**
     * If the key is to be associated with a valid value, a mutation is created
     * for it with the given column family and columns. In the event the value
     * in the column is missing (i.e., null), then it is marked for
     * {@link Deletion}. Similarly, if the entire value for a key is missing
     * (i.e., null), then the entire key is marked for {@link Deletion}.
     * </p>
     *
     * @param keybuff
     *            the key to write.
     * @param value
     *            the value to write.
     * @throws IOException
     */
If the key is to be associated with a valid value, a mutation is created
for it with the given column family and columns. In the event the value
in the column is missing , then it is marked for
Deletion. Similarly, if the entire value for a key is missing
, then the entire key is marked for  Deletion.

@param keybuff
the key to write.
@param value
the value to write.
If the key is to be associated with a valid value a mutation is created for it with the given column family and columns . In the event the value in the column is missing then it is marked for Deletion . Similarly if the entire value for a key is missing then the entire key is marked for Deletion . @param keybuff the key to write . @param value the value to write .
@Override
    public void write(ByteBuffer keybuff, List<Mutation> value) throws IOException
    {
        Range<Token> range = ringCache.getRange(keybuff);
        RangeClient client = clients.get(range);
        if (client == null)
        {
            client = new RangeClient(ringCache.getEndpoint(range));
            client.start();
            clients.put(range, client);
        }
        for (Mutation amut : value)
            client.put(new Pair<ByteBuffer,Mutation>(keybuff, amut));
    }
@ Override public void write ( ByteBuffer keybuff , List < Mutation > value ) throws IOException { Range < Token > range = ringCache . getRange ( keybuff ) ; RangeClient client = clients . get ( range ) ; if ( client == null ) { client = new RangeClient ( ringCache . getEndpoint ( range ) ) ; client . start ( ) ; clients . put ( range , client ) ; } for ( Mutation amut : value ) client . put ( new Pair < ByteBuffer , Mutation > ( keybuff , amut ) ) ; }
If the key is to be associated with a valid value, a mutation is created
 for it with the given column family and columns.
If the key is to be associated with a valid value a mutation is created for it with the given column family and columns .
// get the client for the given range, or create a new one // haven't seen keys for this range: create new client