Magento 2 Site Either Works Super Quick and Responsive, Or Very Slow and Crashes

[jduffin611]

Hi Guys

I upgraded my site from M1 - M2 (2.3.4) in late Dec 2020. My website catalogue has over 1 million SKU's in it, my host has provided me with a custom Dedicated server:

- Dual Intel Xeon E3-1230 v3
- 32GB Memory
- 4x 480GB SSD RAID 10
- Ubuntu 18.04 LTS 64bit

The website seems to work in only 2 ways, either super quick and responsive or Very slow and crashes.

The searches either work Quick or VERY VERY Slow. I currently am using Sphinx search with a pluggin from Mirsavit. There are also only a few pluggins installed, one of which generates a shopping feed for Google Merchant Centre, the other is an Abandoned Cart email reminder plugin. My developers and Hosts have been through it all and can't figure out what is causing this issue.

Anyone got any advice on where I can start looking myself? Or know of anyone who I can hire to look at this issue for me.

[jduffin611]

Forgot to add the website is: www.sparetoolparts.co.uk

[TutorialMagento]

Hello, I suggest to manually disable suspected magento 2 plugins that may cause your website slow one by one and test if the website speed improved after disabling it.

Have you tried that?

I just visited your website and it loads quite fast, the only slow part is search function.

You may try disabling the Magento 2 search plugin installed on your website to figure out if that's the issue.

[JLHC]

Is there a specific reason that you are using Sphinx search instead of Elasticsearch? 

Elasticsearch is supported by Magento out of the box so you do not have to resort to another third-party module/plugin.