Fix high memory usage in CleanupHelper

[zepich]

Issue

The CleanupHelper, executed in the frontend API request, loads all submissions that need to be deleted (https://github.com/mosparo/mosparo/blob/master/src/Helper/CleanupHelper.php#L65). This can be a large number of submissions. The execution of the query will fill the memory until the memory_limit (usually 128 MB) is reached and the process crashes.

Reported by

• @brendofreitas

Discussed in https://github.com/orgs/mosparo/discussions/147

^{Originally posted by brendofreitas October 19, 2023}
I found an error when using mosparo on a large scale, I verified that it is a memory problem. I found a solution that is not so suitable:

https://stackoverflow.com/questions/561066/fatal-error-allowed-memory-size-of-134217728-bytes-exhausted

However, I verified that a different type of lib can also be used to avoid this problem:
https://serverfault.com/questions/400434/php-mysqlnd-or-php-mysql

The error log was:
"

Fatal error: Allowed memory size of 134217728 bytes exhausted (tried to allocate 16384 bytes) in /mosparo/vendor/doctrine/dbal/src/Driver/PDO/Statement.php on line 121



Fatal error: Allowed memory size of 134217728 bytes exhausted (tried to allocate 65536 bytes) in /mosparo/vendor/composer/ClassLoader.php on line 571



Fatal error: Uncaught PDOException: SQLSTATE[HY000]: General error: 2014 Cannot execute queries while other unbuffered queries are active. Consider using PDOStatement::fetchAll(). Alternatively, if your code is only ever going to run against mysql, you may enable query buffering by setting the PDO::MYSQL_ATTR_USE_BUFFERED_QUERY attribute. in /mosparo/vendor/symfony/http-foundation/Session/Storage/Handler/PdoSessionHandler.php:353
Stack trace:
#0 /mosparo/vendor/symfony/http-foundation/Session/Storage/Handler/PdoSessionHandler.php(353): PDOStatement->execute()
#1 /mosparo/vendor/symfony/http-foundation/Session/Storage/Handler/AbstractSessionHandler.php(120): Symfony\Component\HttpFoundation\Session\Storage\Handler\PdoSessionHandler->doWrite('078f5ab84ad06b3...', '_sf2_attributes...')
#2 /mosparo/src/Session/DatabaseSessionHandler.php(64): Symfony\Component\HttpFoundation\Session\Storage\Handler\AbstractSessionHandler->write('078f5ab84ad06b3...', '_sf2_attributes...')
#3 /mosparo/vendor/symfony/http-foundation/Session/Storage/Proxy/SessionHandlerProxy.php(73): Mosparo\Session\DatabaseSessionHandler->write('078f5ab84ad06b3...', '_sf2_attributes...')
#4 [internal function]: Symfony\Component\HttpFoundation\Session\Storage\Proxy\SessionHandlerProxy->write('078f5ab84ad06b3...', '_sf2_attributes...')
#5 {main}
thrown in /mosparo/vendor/symfony/http-foundation/Session/Storage/Handler/PdoSessionHandler.php on line 353

"

How can we resolve this? I believe that when you are searching the bank it is listing all the data to get to a point, which is not necessary. This increases memory usage to a maximum, slowing down and crashing the application and generating this error.