Server High load related to the MySQL activity Presta 1.7.5

[Luk001]

Hello , 

I have Prestashop 1.7.5 one VPS with 6GB ram and 100 GB of hard disk.

I have a big problem with the performance of the web site . I have a lot of query as this this one :Creating sort index | SELECT p.*, product_shop.*, stock.out_of_stock, IFNULL(stock.quantity, 0) AS quantity, IFNULL(product_attribute_shop.id_product_attribute, 0) AS id_product_attribute,
product_attribute_shop.minimal_quantity AS product_attribute_minimal_quantity, pl.`description`, pl.`description_short`, pl.`available_now`,
pl.`available_later`, pl.`link_rewrite`, pl.`meta_description`, pl.`meta_keywords`, pl.`meta_title`, pl.`name`, image_shop.`id_image` id_image,
il.`legend` as legend, m.`name` AS manufacturer_name, cl.`name` AS category_default,
DATEDIFF(product_shop.`date_add`, DATE_SUB("2020-07-05 00:00:00",
INTERVAL 20 DAY)) > 0 AS new, product_shop.price AS orderprice
FROM `pr_category_product` cp
LEFT JOIN `pr_product` p
ON p.`id_product` = cp.`id_product`
INNER JOIN pr_product_shop product_shop
ON (product_shop.id_product = p.id_product AND product_shop.id_shop = 1) LEFT JOIN `pr_product_attribute_shop` product_attribute_shop
ON (p.`id_product` = product_attribute_shop.`id_product` AND product_attribute_shop.`default_on` = 1 AND product_attribute_shop.id_shop=1)
LEFT JOIN pr_stock_available stock
ON (stock.id_product = `p`.id_product AND stock.id_product_attribute = 0 AND stock.id_shop = 1 AND stock.id_shop_group = 0 )
LEFT JOIN `pr_category_lang` cl
ON (product_shop.`id_category_default` = cl.`id_category`
AND cl.`id_lang` = 2 AND cl.id_shop = 1 )
LEFT JOIN `pr_product_lang` pl
ON (p.`id_product` = pl.`id_product`
AND pl.`id_lang` = 2 AND pl.id_shop = 1 )
LEFT JOIN `pr_image_shop` image_shop
ON (image_shop.`id_product` = p.`id_product` AND image_shop.cover=1 AND image_shop.id_shop=1)
LEFT JOIN `pr_image_lang` il
ON (image_shop.`id_image` = il.`id_image`
AND il.`id_lang` = 2)
LEFT JOIN `pr_manufacturer` m
ON m.`id_manufacturer` = p.`id_manufacturer`
WHERE product_shop.`id_shop` = 1
AND cp.`id_category` = 1306 AND product_shop.`active` = 1 AND product_shop.`visibility` IN ("both", "catalog") ORDER BY cp.`position` ASC
LIMIT 0,9 | 0.000 |

And server is busy and a lot of time I have a timeout error

How I can fix it ?

Thanks 

Luca

[musicmaster]

Did you enable profiling and look which queries take most time?

[Guest]

This problem has been known since time immemorial and is not modified in the new version of Prestashop.
Attributes and combinations in an SQL query cause slow loading.
You can try to change the SQL in Category.php.

Categories that contain products without attributes load quickly.