Write php array in HBase using thrift

Question

I have a Thrift php client and I want to write in a HBase table and I'm doing the following:

  $mutations = array(
    new Mutation( array(
      'column' => 'entry:num',
      'value' => array('a','b','c')
    ) ),
  );
  $client->mutateRow( $t, $row, $mutations );

The problem is that when inserting in HBase the value, which is an array, gets converted to 'Array' instead of storing the elements of the array. How can I store the list as an array (or byte array)

Answer 1

A HBase mutation object has required three fields with boolean/text values, not arrays. So you need to turn any structured value into a string, something like.

  $mutations = array(
     new Mutation( array(
       'isDelete' => FALSE,
       'column'   => 'entry:num',
       'value'    => serialize(array('a','b','c'))
     ) ),
   );
   $client->mutateRow( $t, $row, $mutations );

The definition of the HBase Thrift API is here; http://svn.apache.org/viewvc/hbase/trunk/src/main/resources/org/apache/hadoop/hbase/thrift/Hbase.thrift?view=markup

I haven't tested this.

Answer 2

I must admit that I do not have a clue what you're trying to do (perhaps due to a lack of knowledge regarding Thrift and HBase), but if I understood your question correctly, you're trying to write some PHP data structure (array in this case) to a storage media. To achieve this you have to serialize your data somehow. That could be using a custom XML serialization, a custom binary serialization or, perhaps the most simple solution, the PHP internal serialization mechanism provided by serialize() and the corresponding unserialize() .

If you strive for inter-language-interoperability you should use a custom serialization or you have to write a unserialization function that unserializes the PHP serialization format in your target language.

Just a quick example - I don't know where you'd have to put this code, as I don't know exactly what you're doing:

$mutations = array(
    new Mutation(array(
      'column' => 'entry:num',
      'value'  => array('a','b','c')
    )),
  );
$data = serialize($mutations); // $data now is a string
// write $data to storage
// read $readData from storage
$readMutations = unserialize($readData);
// $readMutations == $mutations 
// (but the Mutation instances are not the same instances any more)

Please seee

• serialize()
• unserialize()
• Serializing objects - objects in sessions