ATUM plus MI - Site unusably slow.

BounceOnline

Good day. Our site has become unusable when ATUM and MI are active. Specifically MI. It's consuming huge PHP resources and this hasnt' happened before. Not sure if it's linked to WC updates or what. Basically site freezes up and end up timing out. We have a lot of items in MI so it's not ideal - please advise.

What I’m seeing:

I’ve put 3 tables in your workspace:

Top 20 query/resource patterns by total time

Share of total time (ATUM vs Other)

Top ATUM-related query patterns

From this export:

≈65% of total query time is ATUM/Multi-Inventory related.
(Joins against wp_atum_product_data etc. dominate.)

The single biggest pattern by total time is a query like:
SELECT p.ID FROM wp_posts … LEFT JOIN wp_atum_product_data apd … (apd.price_per_inventory …)
That’s MI logic crossing posts ↔ atum tables (price-per-inventory/availability checks).

Next heaviest buckets are wp_options reads/updates (lots of calls to alloptions and autoload loads). Frequency is high; each is cheap, but the total adds up—this is where object cache (Redis) helps most.

What to do now (targeted):

ATUM MI tuning (biggest win)

If you don’t need MI detail on shop/category archives, turn that off; keep full MI only on single product pages.

Prefer priority inventory selection over dynamic per-inventory price checks if possible (that price_per_inventory join is expensive).

Trim the number of inventories per product where you ca

Salva

Hi BounceOnline

Do you need to set distinct prices per inventory?
If not, disable it from ATUM Settings and check if that fixes your issue.

Best Regards,
Salva.

BounceOnline

Yes, we specifically need that feature, we use it to separate the stock we have on hand from our supplier stock, and often run a lower price on our own stock for promotions. I've been trying to solve this for a few days now - I thought it was my cache, or some other thing on the site, but as soon as ATUM AND ATUM MI are disabled, everything flies, as soon as I add them back, within a few minutes it becomes unusable. This is a new issue, everything was working fine until this week. Actually ATUM by itself is tolerable but with MI it's catastrophic.

Salva

BounceOnline

But if you disable the "price per inventory" feature from ATUM Settings >> Multi-Inventory, does it fix the issue?

This is a new issue, everything was working fine until this week. Actually ATUM by itself is tolerable but with MI it's catastrophic.

And what has changed since then?
Was this caused by an update or something else?

BounceOnline

Hi Jose,

We've been troubleshooting severe and recurring server-load problems on our WooCommerce store, Bounce Online, and after extensive investigation with our hosting provider we have now been able to isolate the problem to ATUM Multi-Inventory.

The server has 24 GB RAM and had been experiencing periods of extremely high PHP/CPU load, at times reaching effectively zero available CPU and causing instability/500 errors.

Our hosting provider initially investigated external crawler traffic and temporarily blocked several Meta and Google bots. However, excessive PHP activity continued even with those blocks in place.

Today we disabled ATUM Multi-Inventory and uninstalled it with the option to remove its data enabled. The accumulated Multi-Inventory data/inventories were therefore removed. We subsequently reinstalled and activated Multi-Inventory, but have not rebuilt the additional inventory records yet.

Following this reset, our hosting provider confirmed that the server load returned to normal and the server became stable. They have since removed the external crawler blocks and the server has remained stable.

ATUM Core remains installed and active throughout, which appears to isolate the problem specifically to Multi-Inventory and/or its accumulated inventory data rather than ATUM Core itself.

This is unfortunately serious enough that we are now considering replacing ATUM Multi-Inventory entirely. Before doing that, however, we'd like to give it one final clean test.

We are considering completely removing both ATUM Multi-Inventory and ATUM Core, including all associated data, and then installing both again from scratch. We would initially create only one additional inventory location and add products gradually while monitoring server load.

Before we do this, could you please advise whether there is any database information, logs, tables or other diagnostic data from the existing installation that you would like us to preserve or provide to you?

We'd also appreciate confirmation of:

Exactly which database tables/options/product metadata should be removed for a genuinely clean ATUM + Multi-Inventory installation.
Whether you are aware of any Multi-Inventory issue that can cause excessive PHP processing or database queries as inventory records accumulate.
Whether there are any scheduled processes, hooks or background tasks specific to Multi-Inventory that we should investigate.
Whether there are known performance limitations with Multi-Inventory on larger WooCommerce catalogues.
Our intended setup is actually relatively simple. Going forward, WooCommerce/ATUM Main Inventory would hold our supplier-feed stock, while Multi-Inventory would only contain one additional inventory representing our own physical shop/warehouse stock. We do not need large numbers of supplier inventories.

We can provide server logs, database information or other diagnostics if required. Our hosting provider is also actively monitoring the server and can confirm the load behaviour before and after the Multi-Inventory reset.

Kind regards,
Chris
Bounce Online

Salva

Hi BounceOnline

FYI, there have been a lot of performance improvements since ATUM 2.0.
And we are not aware of any kind of issue like the one you mention at this time.
The information you are providing is too vague, and the reason of you issue can be anything.
I would recommend you find a developer to assist you in doing a deep debugging of the code and finding the real cause of the issue instead of blindly trying things like uninstalling and reinstalling plugins that, in my opinion, will help very little to resolve your problem.
And database info, logs, and that kind of information would only help if you are seeing errors in your logs when this happens. Sadly, this is not always the case...
But if you are seeing errors in your PHP error log directly related to ATUM, please open a private ticket, send us the log, and we will check it out.

Best Regards,
Salva.