Undefined index error upon $em->clear() in Symfony2

Question

I have written a Symfony command to import some data from an API. It works but the problem is my PHP memory usage increases when I insert a big JSON in my database. And my unitOfWork increases by '2' to after each activty import.

I have already unset all my used objects, and I have read the documentation of Symfony2 when you want to do massive batch: http://www.doctrine-project.org/blog/doctrine2-batch-processing.html

But when I use $em->clear() my entity manager gives this error:

Notice: Undefined index: 000000007b56ea7100000000e366c259 in path-to-application\vendor\doctrine\lib\Doctrine\ORM\UnitOfWork.php line 2228

Here is my complete code :

 /**
 * @see Command
 */
protected function configure() {
  $this
    ->setName('ks:user:runkeepersync')
    ->setDescription('Synchroniser les activités d\'un utilisateur runkeeper')
    ->setDefinition(array(
      new InputArgument('access_token', InputArgument::REQUIRED, 'Access token'),
    ))
}

/**
 * @see Command
 */
protected function execute(InputInterface $input, OutputInterface $output) {
  $accessToken = $input->getArgument('access_token');
  $em = $this->getContainer()->get('doctrine')->getEntityManager();
  $UserHasServices = $em->getRepository('KsUserBundle:UserHasServices')->findOneByToken($accessToken);
  if (!is_object($UserHasServices) ) {
    echo "Impossible de trouver l'utilisateur qui possède le jeton ".$accessToken."";
  }
  $user    = $UserHasServices->getUser();
  $service = $UserHasServices->getService();
  echo "avant de requérir l'api : ".memory_get_usage()."\n";
  try {
    $rkApi = $this->getContainer()->get('ks_user.runkeeper');
    $rkApi->setAccessToken($accessToken);
    $activities  = $rkApi->getFitnessActivities(0,25);
    $nbParPages  = 25;
    $nomberActivitites = $activities->size;
    $aActivities = $activities->items;
    $nbPages =  floor ($nomberActivitites/$nbParPages);
    $aEndurance = array("Running", "Cycling", "Mountain Biking", "Walking", "Hiking", "Downhill Skiing", "Cross-Country Skiing", "Snowboarding", "Skating","Wheelchair", "Rowing", "Elliptical", "Other");
    $aEnduranceUnderWater = array("Swimming");
    $enduranceOnEarthType = $em->getRepository('KsActivityBundle:SportType')->findOneByLabel("endurance");
    if (!is_object($enduranceOnEarthType) ) {
      echo "Impossible de trouver le type de sport d'endurance";
    }
    $enduranceUnderWaterType = $em->getRepository('KsActivityBundle:SportType')->findOneByLabel("endurance_under_water");
    if (!is_object($enduranceUnderWaterType) ) {
      echo "Impossible de trouver le type de sport d'endurance sous l'eau ";
    }
    echo "Après avoir récupéré 25 activités : ".memory_get_usage()."\n";
    $a = 0;
    for($i=0;$i<=$nbPages;$i++){
      if($i!=0){
        $activities  = $rkApi->getFitnessActivities($i,25);
        $aActivities = $activities->items;
      }
      foreach ($aActivities as $activity) {
        $a = $a+1;
        $codeSport = $this->formatNameSport($activity->type);
        $sport = $em->getRepository('KsActivityBundle:Sport')->findOneByCodeSport($codeSport);
        if (!is_object($sport) ) {
          $sport = new \Ks\ActivityBundle\Entity\Sport();
          $sport->setLabel($codeSport);
          $sport->setCodeSport($codeSport);
          $sport->setSportType($enduranceOnEarthType);
          $em->persist($sport);
          $em->flush();
        }
        $activityDetail = json_decode($rkApi->requestJSONHealthGraph($activity->uri));
        if(in_array($activity->type, $aEndurance)){
          $urlActivitieDetail = $activityDetail->activity;
          $ActivitySessionEnduranceOnEarth = new \Ks\ActivityBundle\Entity\ActivitySessionEnduranceOnEarth($user);
          isset($activity->total_distance)? $ActivitySessionEnduranceOnEarth->setDistance($activity->total_distance) : "";
          isset($activity->duration)? $ActivitySessionEnduranceOnEarth->setDuration($this->secondesToTimeDuration($activity->duration)) : "";
          isset($activity->start_time)?  $ActivitySessionEnduranceOnEarth->setIssuedAt(new \DateTime($activity->start_time)) : "";
          $ActivitySessionEnduranceOnEarth->setModifiedAt(new \DateTime('Now'));
          $ActivitySessionEnduranceOnEarth->setSport($sport);
          isset($activityDetail->total_calories)?  $ActivitySessionEnduranceOnEarth->setCalories($activityDetail->total_calories) : "";
          isset($activityDetail->climb)?  $ActivitySessionEnduranceOnEarth->setElevationGain($activityDetail->climb) : "";
          $maxElevation = 0;
          $minElevation = 10000;
          if(isset($activityDetail->path)){
            foreach($activityDetail->path as $gpsPoint){
              if($gpsPoint->altitude > $maxElevation){
                $maxElevation = $gpsPoint->altitude;
              }
              if($gpsPoint->altitude < $minElevation){
                $minElevation = $gpsPoint->altitude;
              }
            }
            $ActivitySessionEnduranceOnEarth->setElevationMin($minElevation);
            $ActivitySessionEnduranceOnEarth->setElevationMax($maxElevation);
          }
          $em->persist($ActivitySessionEnduranceOnEarth);
          $em->flush();
          //Pour chaque activité on a un identifiant relatif au service qu'on synchronise
          $ActivityComeFromService = new \Ks\ActivityBundle\Entity\ActivityComeFromService();
          $ActivityComeFromService->setActivity($ActivitySessionEnduranceOnEarth);
          $ActivityComeFromService->setService($service);
          $ActivityComeFromService->setIdWebsiteActivityService($activity->uri);
          $ActivityComeFromService->setSourceDetailsActivity($rkApi->requestJSONHealthGraph($activity->uri));
          $ActivityComeFromService->setTypeSource("JSON");
          $em->persist($ActivityComeFromService);
          $em->flush();
          echo "Import de l'activite num ".$a." type :".$activity->type." effectue avec success \n";
          unset($ActivitySessionEnduranceOnEarth);
          unset($ActivityComeFromService);
          echo "UnitOFWOrk -> ".$em->getUnitOfWork()->size()."\n";
        }
        if(in_array($activity->type, $aEnduranceUnderWater)){
          $ActivitySessionEnduranceUnderWater = new \Ks\ActivityBundle\Entity\ActivitySessionEnduranceUnderWater($user);
          isset($activity->total_distance)? $ActivitySessionEnduranceUnderWater->setDistance($activity->total_distance) : "";
          isset($activity->duration)? $ActivitySessionEnduranceUnderWater->setDuration($this->secondesToTimeDuration($activity->duration)) : "";
          isset($activity->start_time) && !empty($activity->start_time)?  $ActivitySessionEnduranceUnderWater->setIssuedAt(new \DateTime($activity->start_time)) : "";
          $ActivitySessionEnduranceUnderWater->setModifiedAt(new \DateTime('Now'));
          $ActivitySessionEnduranceUnderWater->setSport($sport);
          isset($activityDetail->total_calories)?  $ActivitySessionEnduranceUnderWater->setCalories($activityDetail->total_calories) : "";
          isset($activityDetail->notes)?  $ActivitySessionEnduranceUnderWater->setDescription($activityDetail->notes) : "";
          $em->persist($ActivitySessionEnduranceUnderWater);
          $em->flush();
          $ActivityComeFromService = new \Ks\ActivityBundle\Entity\ActivityComeFromService();
          $ActivityComeFromService->setActivity($ActivitySessionEnduranceUnderWater);
          $ActivityComeFromService->setService($service);
          $ActivityComeFromService->setIdWebsiteActivityService($activity->uri);
          $ActivityComeFromService->setSourceDetailsActivity($rkApi->requestJSONHealthGraph($activity->uri));
          $ActivityComeFromService->setTypeSource("JSON");
          $em->persist($ActivityComeFromService);
          $em->flush();
          echo "Import de l'activité num ".$a." type :".$activity->type." effectué avec succès\n";
          unset($ActivitySessionEnduranceUnderWater);
          unset($ActivityComeFromService);
        }
        echo "Après chaque activité : ".memory_get_usage()."\n";
        unset($sport);
        unset($activityDetail);
        $em->clear();
      }
    }
  } catch (\Exception $e) {
    throw $e;
  }
}

Thanks, @AdrienBrault. I have tested with --env=prod --no-debug, and it is true that it consumes less memory, but the memory still increase. How can I really clear the entity manager? and stabilize the memory?

Answer 1

Symfony logs all SQL queries in dev environment, so first you need to disable it

// disable logger
$em->getConnection()->getConfiguration()->setSQLLogger(null);

You may use event listeners on entities, it may also increase memory usage. You can disable them like so

// remove all listeners
foreach ($em->getEventManager()->getListeners() as $event => $listeners) {
    foreach ($listeners as $listener) {
        $em->getEventManager()->removeEventListener($event, $listener);
    }
}

Remove unset from your code, there is no need for them, as you clear entity manager every step of your loop.

// save and clear
$em->flush();
$em->getUnitOfWork()->clear();

Remember that doctrine can optimize your queries, and improve perfomance if you group queries into one flush. So the best practice would be to execute flush once over some parts of your data. For example:

// collect 100 entities and then save them
if (($i % 100) == 0) {
    $em->flush();
    $em->getUnitOfWork()->clear();
}

Answer 2

Try to reset the entity manager with:

$this->getContainer()->get('doctrine')->resetEntityManager();

and then:

$em = $this->getContainer()->get('doctrine')->getEntityManager();