使用php备份数据时出现内存不足问题

我使用yii模块备份sql数据库，我注意到如下错误： 致命错误：内存不足（已分配295436288）（尝试分配225446869字节）

因为我的数据库太大，我正在浏览上面的内容并出错。我能在这里做些什么？我读了一些文章，我可以使用flush（）函数来减少内存使用

<?php
/**
  * Backup
  *
  * Yii module to backup, restore databse
  *
  * @version 1.0
  * @author Shiv Charan Panjeta <shiv@toxsl.com>   <shivcharan.panjeta@outlook.com>
 */
class DefaultController extends Controller
 {

/**
 * @var string the default layout for the views. Defaults to '//layouts/column2', meaning
 * using two-column layout. See 'protected/views/layouts/column2.php'.
 */
public $layout='//layouts/column2';

/**
 * @return array action filters
 */
public function filters()
{
    return array(
            'accessControl', // perform access control for CRUD operations
    );
}

/**
 * Specifies the access control rules.
 * This method is used by the 'accessControl' filter.
 * @return array access control rules
 */
public function accessRules()
{
    return array(
    array('allow',  // allow all users to perform 'index' and 'view' actions
                    'actions'=>array('create1'),
                    'users'=>array('*'),
    ),
    array('allow', // allow authenticated user to perform 'create' and 'update' actions
                    'actions'=>array(),
                    'users'=>array('@'),
    ), 
    array('allow', // allow admin user to perform 'admin' and 'delete' actions
                    'actions'=>array('admin','delete','clean','index','view','create','upload', 'download','restore'),
                    'users'=>array('admin'),
    ),
    array('deny',  // deny all users
                    'users'=>array('*'),
    ),
    );
}


public $tables = array();
public $fp ;
public $file_name;
public $_path = null;
public $back_temp_file = 'db_backup_';

protected function getPath()
{
    if ( isset ($this->module->path )) $this->_path = $this->module->path;
    else $this->_path = Yii::app()->basePath .'/../_backup/';

    if ( !file_exists($this->_path ))
    {
        mkdir($this->_path );
        chmod($this->_path, '777');
    }
    return $this->_path;
}
public function execSqlFile($sqlFile)
{
    $message = "ok";

    if ( file_exists($sqlFile))
    {
        $sqlArray = file_get_contents($sqlFile);

        $cmd = Yii::app()->db->createCommand($sqlArray);
        try {
            $cmd->execute();
        }
        catch(CDbException $e)
        {
            $message = $e->getMessage();
        }

    }
    return $message;
}
public function getColumns($tableName)
{
    $sql = 'SHOW CREATE TABLE '.$tableName;
    $cmd = Yii::app()->db->createCommand($sql);
    $table = $cmd->queryRow();

    $create_query = $table['Create Table'] . ';';

    $create_query  = preg_replace('/^CREATE TABLE/', 'CREATE TABLE IF NOT EXISTS', $create_query);
    //$create_query = preg_replace('/AUTO_INCREMENT\s*=\s*([0-9])+/', '', $create_query);
    if ( $this->fp)
    {
        $this->writeComment('TABLE `'. addslashes ($tableName) .'`');
        $final = 'DROP TABLE IF EXISTS `' .addslashes($tableName) . '`;'.PHP_EOL. $create_query .PHP_EOL.PHP_EOL;
        fwrite ( $this->fp, $final );
    }
    else
    {
        $this->tables[$tableName]['create'] = $create_query;
        return $create_query;
    }
}

public function getData($tableName)
{
    $sql = 'SELECT * FROM '.$tableName;
    $cmd = Yii::app()->db->createCommand($sql);
    $dataReader = $cmd->query();

    $data_string = '';

    foreach($dataReader as $data)
    {
        $itemNames = array_keys($data);
        $itemNames = array_map("addslashes", $itemNames);
        $items = join('`,`', $itemNames);
        $itemValues = array_values($data);
        $itemValues = array_map("addslashes", $itemValues);
        $valueString = join("','", $itemValues);
        $valueString = "('" . $valueString . "'),";
        $values ="\n" . $valueString;
        if ($values != "")
        {
            $data_string .= "INSERT INTO `$tableName` (`$items`) VALUES" . rtrim($values, ",") . ";" . PHP_EOL;
        }
    }

    if ( $data_string == '')
    return null;

    if ( $this->fp)
    {
        $this->writeComment('TABLE DATA '.$tableName);
        $final = $data_string.PHP_EOL.PHP_EOL.PHP_EOL;
        fwrite ( $this->fp, $final );
    }
    else
    {
        $this->tables[$tableName]['data'] = $data_string;
        return $data_string;
    }
}
public function getTables($dbName = null)
{
    $sql = 'SHOW TABLES';
    $cmd = Yii::app()->db->createCommand($sql);
    $tables = $cmd->queryColumn();
    return $tables;
}
public function StartBackup($addcheck = true)
{
    $this->file_name =  $this->path . $this->back_temp_file . date('Y.m.d_H.i.s') . '.sql';

    $this->fp = fopen( $this->file_name, 'w+');

    if ( $this->fp == null )
    return false;
    fwrite ( $this->fp, '-- -------------------------------------------'.PHP_EOL );
    if ( $addcheck )
    {
        fwrite ( $this->fp,  'SET AUTOCOMMIT=0;' .PHP_EOL );
        fwrite ( $this->fp,  'START TRANSACTION;' .PHP_EOL );
        fwrite ( $this->fp,  'SET SQL_QUOTE_SHOW_CREATE = 1;'  .PHP_EOL );
    }
    fwrite ( $this->fp, 'SET @OLD_UNIQUE_CHECKS=@@UNIQUE_CHECKS, UNIQUE_CHECKS=0;'.PHP_EOL );
    fwrite ( $this->fp, 'SET @OLD_FOREIGN_KEY_CHECKS=@@FOREIGN_KEY_CHECKS, FOREIGN_KEY_CHECKS=0;'.PHP_EOL );
    fwrite ( $this->fp, '-- -------------------------------------------'.PHP_EOL );
    $this->writeComment('START BACKUP');
    return true;
}
public function EndBackup($addcheck = true)
{
    fwrite ( $this->fp, '-- -------------------------------------------'.PHP_EOL );
    fwrite ( $this->fp, 'SET FOREIGN_KEY_CHECKS=@OLD_FOREIGN_KEY_CHECKS;'.PHP_EOL );
    fwrite ( $this->fp, 'SET UNIQUE_CHECKS=@OLD_UNIQUE_CHECKS;'.PHP_EOL );

    if ( $addcheck )
    {
        fwrite ( $this->fp,  'COMMIT;' .PHP_EOL );
    }
    fwrite ( $this->fp, '-- -------------------------------------------'.PHP_EOL );
    $this->writeComment('END BACKUP');
    fclose($this->fp);
    $this->fp = null;
}

public function writeComment($string)
{
    fwrite ( $this->fp, '-- -------------------------------------------'.PHP_EOL );
    fwrite ( $this->fp, '-- '.$string .PHP_EOL );
    fwrite ( $this->fp, '-- -------------------------------------------'.PHP_EOL );
}
public function actionCreate()
{
    set_time_limit(0);
    $tables = $this->getTables();

    if(!$this->StartBackup())
    {
        //render error
        $this->render('create');
        return;
    }

    foreach($tables as $tableName)
    {
        $this->getColumns($tableName);
    }
    foreach($tables as $tableName)
    {
        $this->getData($tableName);
    }
    $this->EndBackup();

    $this->redirect(array('index'));
}
public function actionClean($redirect = true)
{
    $tables = $this->getTables();

    if(!$this->StartBackup())
    {
        //render error
        return;
    }

    foreach($tables as $tableName)
    {
        fwrite ( $this->fp, '-- -------------------------------------------'.PHP_EOL );
        fwrite ( $this->fp, 'DROP TABLE IF EXISTS ' .addslashes($tableName) . ';'.PHP_EOL );
        fwrite ( $this->fp, '-- -------------------------------------------'.PHP_EOL );

    }
    $this->EndBackup();

    // logout so there is no problme later .
    Yii::app()->user->logout();

    $this->execSqlFile($this->file_name);
    unlink($this->file_name);
    if ( $redirect == true) $this->redirect(array('index'));
}
public function actionDelete($file = null)
{
    $this->updateMenuItems();
    if ( isset($file))
    {
        $sqlFile = $this->path . basename($file);
        if ( file_exists($sqlFile))
        unlink($sqlFile);
    }
    else throw new CHttpException(404, Yii::t('app', 'File not found'));
    $this->actionIndex();
}

public function actionDownload($file = null)
{
    $this->updateMenuItems();
    if ( isset($file))
    {
        $sqlFile = $this->path . basename($file);
        if ( file_exists($sqlFile))
        {
            $request = Yii::app()->getRequest();
            $request->sendFile(basename($sqlFile),file_get_contents($sqlFile));
        }
    }
    throw new CHttpException(404, Yii::t('app', 'File not found'));
}

public function actionIndex()
{
    $this->updateMenuItems();
    $path = $this->path;

    $dataArray = array();

    $list_files = glob($path .'*.sql');
    if ($list_files )
    {
        $list = array_map('basename',$list_files);
        sort($list);


        foreach ( $list as $id=>$filename )
        {
            $columns = array();
            $columns['id'] = $id;
            $columns['name'] = basename ( $filename);
            $columns['size'] = floor(filesize ( $path. $filename)/ 1024) .' KB';
            $columns['create_time'] = date( DATE_RFC822, filectime($path .$filename) );
            $dataArray[] = $columns;
        }
    }
    $dataProvider = new CArrayDataProvider($dataArray);
    $this->render('index', array(
        'dataProvider' => $dataProvider,
    ));
}
public function actionSyncdown()
{
    $tables = $this->getTables();

    if(!$this->StartBackup())
    {
        //render error
        $this->render('create');
        return;
    }

    foreach($tables as $tableName)
    {
        $this->getColumns($tableName);
    }
    foreach($tables as $tableName)
    {
        $this->getData($tableName);
    }
    $this->EndBackup();
    $this->actionDownload(basename($this->file_name));
}

public function actionRestore($file = null)
{
    $this->updateMenuItems();
    $message = 'OK. Done';
    $sqlFile = $this->path . 'install.sql';
    if ( isset($file))
    {
        $sqlFile = $this->path . basename($file);
    }

    $this->execSqlFile($sqlFile);
    $this->render('restore',array('error'=>$message));
}

public function actionUpload()
{
    $model= new UploadForm('upload');
    if(isset($_POST['UploadForm']))
    {
        $model->attributes = $_POST['UploadForm'];
        $model->upload_file = CUploadedFile::getInstance($model,'upload_file');
        if($model->upload_file->saveAs($this->path . $model->upload_file))
        {
            // redirect to success page
            $this->redirect(array('index'));
        }
    }

    $this->render('upload',array('model'=>$model));
}

protected function updateMenuItems($model = null)
{
    // create static model if model is null
    if ( $model == null ) $model=new UploadForm('install');

    switch( $this->action->id)
    {
        case 'restore':
            {
                $this->menu[] = array('label'=>Yii::t('app', 'View Site') , 'url'=>Yii::app()->HomeUrl);
            }
        case 'create':
            {
                $this->menu[] = array('label'=>Yii::t('app', 'List Backup') . ' ' . $model->label(2), 'url'=>array('index'));
            }
            break;
        case 'upload':
            {
                $this->menu[] = array('label'=>Yii::t('app', 'Create Backup') . ' ' . $model->label(), 'url'=>array('create'));
            }
            break;
        default:
            {
                $this->menu[] = array('label'=>Yii::t('app', 'List Backup') . ' ' . $model->label(2), 'url'=>array('index'));
                $this->menu[] = array('label'=>Yii::t('app', 'Create Backup') . ' ' . $model->label(), 'url'=>array('create'));
                //$this->menu[] = array('label'=>Yii::t('app', 'Upload Backup') . ' ' . $model->label(), 'url'=>array('upload'));
                //$this->menu[] = array('label'=>Yii::t('app', 'Restore Backup') . ' ' . $model->label(), 'url'=>array('restore'));
                //$this->menu[] = array('label'=>Yii::t('app', 'Clean Database') . ' ' . $model->label(), 'url'=>array('clean'));
                //$this->menu[] = array('label'=>Yii::t('app', 'View Site') , 'url'=>Yii::app()->HomeUrl);
            }
            break;
    }
}
}

---

分配了295436288字节，相当于295MB

正如你所说，你把它设置为2GB。您可能在php.ini中做错了，或者您正在处理的代码可能有设置内存使用的限制或选项

无论如何，在php.ini发生更改后，您是否重新启动了服务器

新编辑：

Do your server have enough(2GB, as you tried to set) free memory(RAM).

您是通过CGI还是CLI调用此功能？您可以在php.ini中增加
内存限制的值。我已经在php.ini上设置了内存限制。但仍然会得到这样的关注。我在yii备份模块上调用该类…然后可能使用
mysqldump
之类的工具转储数据库，如果数据库太大，则不使用PHP。我的项目经理想在web应用程序上添加sql备份功能。那么最好的解决方案是什么呢？是否删除此功能？当数据库太大时，是否创建一个警报限制函数？在服务器上添加更多内存？优化代码？如果您处于我的位置，您会选择什么？您的服务器是否有足够的（2GB，正如您试图设置的）空闲内存（RAM）。那么，我必须在php.ini上设置内存限制的值是多少？我总是在每次更改时重新启动服务器。@IIMNURDIANSYAH您是否在本地主机上，以及框架是什么，如果有。我想没有，我的可用内存可能只有1。1GB@IIMNURDIANSYAH那这差不多就是答案了。如何分配比现有内存更大的内存。您有1.1G nad和2G。尝试800米，将其改为800米，但仍有错误。sql文件只有321832KB（在我的数据库中大约是700MB）