PHP sf.1.4 Propel 1.6: memory leaking while looping results

Question

I am working with symfony 1.4 + propel 1.6 and I want to export (index) all my user database to ElasticSearch.

I have written all the script and everything is working okay, besides one problem. I make a loop that repeats about 20.000~ times and with everytime the memory_usage increases.

Problem is: it shouldn't, because I am destroying all the references.

I think Propel is leaving somewhere a static reference to the every object I create. Can't find it though, because I already disabled the instance pooling.

Anybody had ever a similar problem? Maybe someone has an idea how can I debug the PHP memory limits? (webgrind doesnt) I spent last few hours on this piece of code debugging and still can't fix it.

// optimizations
    gc_enable();
    Propel::getConnection()->useDebug(false);
    Propel::disableInstancePooling();
// the while
    $offset = 0;
    $perpage = 10;
    $c = SearchUserQuery::create()->limit($perpage);
    do {
        $rs = SearchUserPeer::doSelectStmt($c);
        while ($row = $rs->fetch(PDO::FETCH_NUM))
        {
            $instance = new SearchUser();
            $instance->hydrate($row);
            $data = $instance->toElastic(); // this line makes a lot of memory leak
            $_document = new Elastica\Document($instance->getPrimaryKey(), $data);
            $_type->addDocument($_document);
            unset($_document, $instance);
        }
        $c->offset($offset += $perpage);
    } while( $rs->rowCount() );

Function $instance->toElastic is sth like that:

public function toElastic()
{
    return Array(
        'profile' => $this->toArray(BasePeer::TYPE_COLNAME, false),
        'info' => $this->getUserInfo()->toArray(BasePeer::TYPE_COLNAME, false),
        'branches' => $this->getElasticBranches(),
    );
}

/**
 * @return array(id,name)
 */
public function getElasticBranches()
{
    $branches = Array();
    foreach ($this->getsfGuardUser()->getUserBranchs() as $branch)
        $branches[] = Array(
            'id' => $branch->getBranchId(),
            'name' => $branch->getName()
        );
    return $branches;
}

Answer 1

Have you tried this before unsetting?

// garbage collector problem in PHP 5.3
$instance->clearAllReferences(true);

// remove the variable content before removing the address (with unset)
$instance = null;
$_document = null;
$_type = null;

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