Memory exhaustion when load testing with the php couchbase sdk,

I am having difficulty running a load test on a simple connection. My setup is CentOS 6, PHP 5.3, Couchbase SDK 2.0 and Apache webserver. I am getting the following error with about 500 GETs per second. It is trying to allocate ALOT of ram.

PHP Fatal error:  Allowed memory size of 536870912 bytes exhausted (tried to allocate 139698307493912 bytes) in Unknown on line 0

My code below

$cluster = new CouchbaseCluster('','','');
$bucket = $cluster->openBucket('default');

$data =array(
'key1' => array('value' => 'value1'),
'key2' => array('value' => 'value2')
$value = $bucket->upsert($data);

echo "<pre>";
echo "</pre>";

Hey fnsnoop,
How is your PHP installed with Apache? Are you using a multi-threaded Apache request processor?
Cheers, Brett

New version released! I have a few confirmations that it fixes the known issues you were encountering.
Read more here:

Cheers, Brett