Uncaught Error: Call to undefined method Magento\\Catalog\\Model\\ResourceModel\\Product\\Interceptor::_construct()

Question

I am getting the following error in my Magento application sometimes, it's not breaking the application always but in regular interval I am getting this error.

The application CPU usage is also going high sometimes. Application is using redis for both caching and session. Database is AWS Aurora.

[Tue Jul 16 15:41:41.849749 2019] [:error] [pid 6506] [client 10.101.8.81:26870] PHP Fatal error: Uncaught Error: Call to undefined method Magento\Catalog\Model\ResourceModel\Product\Interceptor::_construct() in /mnt/drive1/www/magento-2019-07-08-06-50-51/vendor/magento/framework/Model/ResourceModel/AbstractResource.php:40\nStack trace:\n#0 /mnt/drive1/www/magento-2019-07-08-06-50-51/vendor/magento/module-eav/Model/Entity/AbstractEntity.php(234): Magento\Framework\Model\ResourceModel\AbstractResource->__construct()\n#1 /mnt/drive1/www/magento-2019-07-08-06-50-51/vendor/magento/module-catalog/Model/ResourceModel/AbstractResource.php(51): Magento\Eav\Model\Entity\AbstractEntity->__construct(Object(Magento\Eav\Model\Entity\Context), Array)\n#2 /mnt/drive1/www/magento-2019-07-08-06-50-51/vendor/magento/module-catalog/Model/ResourceModel/Product.php(130): Magento\Catalog\Model\ResourceModel\AbstractResource->__construct(Object(Magento\Eav\Model\Entity\Context), Object(Magento\Store\Model\StoreManager), Object(Magento\Catalog\Model\Factory), Array)\n#3 /mnt/drive1/www/magento-2019-07-08-06-50-51/generated/code/Magen in /mnt/drive1/www/magento-2019-07-08-06-50-51/vendor/magento/framework/Model/ResourceModel/AbstractResource.php on line 40,

Another similar error

PHP Fatal error: Couldn't execute method Composer\Autoload\ClassLoader::composer\autoload\classloader::loadclass\x03 in Unknown on line 0, referer:

Answer 1

Have you tried clearing generated directories?

Enable Maintenance Mode, then:

rm -rf /path-to-install-dir/generated/code/* /path-to-install-dir/generated/metadata/*

After that,

bin/magento setup:upgrade
bin/magento setup:di:compile
bin/magento cache:clean

If you're not in a production environment, you can clear redis cache by running

redis-cli:flushall

You may need to update/upgrade composer as well.