Excessive index invalidation on product category relation removal

[siimm]

In M2 the indexers have their specific order, e.g. price index must be reindexed prior to fulltext index etc.

When magento invalidates indexes, it takes the order of indexes into account.
Before 2.3.5, when an index got invalidated, it looked at the next indexes that were after it and which ever were declared as dependent on current, got invalidated as well.
In 2.3.5 and greater version upon invalidation, the index looks “both-ways” the indexes that came before and after it and were dependent got invalidated.

In clean 2.3.3, catalog_category index and catalogsearch_fulltext index get invalidated when for an example a product is removed from a category.
In clean 2.3.5 and greater version also price indexer and catalogrule indexer get invalidated because of the previously described both ways lookup. (also additionally both target-rule indexers and inventory indexer can get invalidated, depending on their state - update on save or mview)

The cause of the change was some Magento's internal ticket about not finding a product on Elasticsearch: 31aebbf

On a heavy traffic webshop(1k-3k continuous concurrent users) with a lot of products (around 100k) it is not possible to allow rebuilding of such amount of indexes on each category removal from product, as for an example the fulltext index alone takes around 10 minutes to rebuild. Removing and adding products to categories is a fairly common operation on daily bases and with current codebase the webshop enters a continues reindexing and cache cleaning loop.

Preconditions (*)

1. Magento 2.4.0 or Magento 2.3.5 (Also present in 2.4-develop)
2. Set in Admin -> System -> Index Managment all indexers to be 'Update by schedule'

Steps to reproduce (*)

1. Remove a category from product on admin panel product edit form

Expected result (*)

1. No (or as less as possible) indexes completely invalidated

Actual result (*)

1. 6 indexes completely invalidated - bin/magento i:status command shows invalidated: catalogrule_rule, catalogsearch_fulltext, catalog_category_product, inventory, catalog_product_price, cataloginventory_stock forcing next incremental indexer run to reindex all of them

---

Please provide Severity assessment for the Issue as Reporter. This information will help during Confirmation and Issue triage processes.

• Severity: S0 - Affects critical data or functionality and leaves users without workaround.
• Severity: S1 - Affects critical data or functionality and forces users to employ a workaround.
• Severity: S2 - Affects non-critical data or functionality and forces users to employ a workaround.
• Severity: S3 - Affects non-critical data or functionality and does not force users to employ a workaround.
• Severity: S4 - Affects aesthetics, professional look and feel, “quality” or “usability”.

[m2-assistant]

Hi @siimm. Thank you for your report.
To help us process this issue please make sure that you provided the following information:

• Summary of the issue
• Information on your environment
• Steps to reproduce
• Expected and actual results

Please make sure that the issue is reproducible on the vanilla Magento instance following Steps to reproduce. To deploy vanilla Magento instance on our environment, please, add a comment to the issue:

@magento give me 2.4-develop instance - upcoming 2.4.x release

For more details, please, review the Magento Contributor Assistant documentation.

Please, add a comment to assign the issue: @magento I am working on this

---

• Join Magento Community Engineering Slack and ask your questions in #github channel.

⚠️ According to the Magento Contribution requirements, all issues must go through the Community Contributions Triage process. Community Contributions Triage is a public meeting.

🕙 You can find the schedule on the Magento Community Calendar page.

📞 The triage of issues happens in the queue order. If you want to speed up the delivery of your contribution, please join the Community Contributions Triage session to discuss the appropriate ticket.

🎥 You can find the recording of the previous Community Contributions Triage on the Magento Youtube Channel

✏️ Feel free to post questions/proposals/feedback related to the Community Contributions Triage process to the corresponding Slack Channel

[m2-assistant]

Hi @engcom-Oscar. Thank you for working on this issue.
In order to make sure that issue has enough information and ready for development, please read and check the following instruction: 👇

• 1. Verify that issue has all the required information. (Preconditions, Steps to reproduce, Expected result, Actual result).

  Details

  If the issue has a valid description, the label Issue: Format is valid will be added to the issue automatically. Please, edit issue description if needed, until label Issue: Format is valid appears.

• 2. Verify that issue has a meaningful description and provides enough information to reproduce the issue. If the report is valid, add Issue: Clear Description label to the issue by yourself.

• 3. Add Component: XXXXX label(s) to the ticket, indicating the components it may be related to.

• 4. Verify that the issue is reproducible on 2.4-develop branch

  Details

  - Add the comment @magento give me 2.4-develop instance to deploy test instance on Magento infrastructure.
  - If the issue is reproducible on 2.4-develop branch, please, add the label Reproduced on 2.4.x.
  - If the issue is not reproducible, add your comment that issue is not reproducible and close the issue and stop verification process here!

• 5. Add label Issue: Confirmed once verification is complete.

• 6. Make sure that automatic system confirms that report has been added to the backlog.

[magento-engcom-team]

✅ Confirmed by @engcom-Oscar
Thank you for verifying the issue. Based on the provided information internal tickets MC-37445 were created

Issue Available: @engcom-Oscar, You will be automatically unassigned. Contributors/Maintainers can claim this issue to continue. To reclaim and continue work, reassign the ticket to yourself.

[melnickforever]

Do you have any update for this issue ?

[AleksandrsZascirinskis]

Hey, Is there any updates, maybe some fixes that we can apply manually?

[siimm]

@AleksandrsZascirinskis
our way was to revert half of the dependancy processing. No problems encountered

--- Model/Indexer/DependencyDecorator-o.php	2020-05-14 15:23:25.000000000 +0200
+++ Model/Indexer/DependencyDecorator.php	2020-05-14 15:24:02.000000000 +0200
@@ -222,16 +222,9 @@
     public function invalidate()
     {
         $this->indexer->invalidate();
-        $currentIndexerId = $this->indexer->getId();
-        $idsToRunBefore = $this->dependencyInfoProvider->getIndexerIdsToRunBefore($currentIndexerId);
-        $idsToRunAfter = $this->dependencyInfoProvider->getIndexerIdsToRunAfter($currentIndexerId);
-
-        $indexersToInvalidate = array_unique(array_merge($idsToRunBefore, $idsToRunAfter));
-        foreach ($indexersToInvalidate as $indexerId) {
-            $indexer = $this->indexerRegistry->get($indexerId);
-            if (!$indexer->isInvalid()) {
-                $indexer->invalidate();
-            }
+        $dependentIndexerIds = $this->dependencyInfoProvider->getIndexerIdsToRunAfter($this->indexer->getId());
+        foreach ($dependentIndexerIds as $indexerId) {
+            $this->indexerRegistry->get($indexerId)->invalidate();
         }
     }

[xpoback]

@siimm Thanks, that's what I was looking for.

It unbelievably annoying than when I want to rebuild an index (just one) the bunch of other indices has to be built before that. For example, when rebuilding the search index (catalogsearch_fulltext), five (5) others have to be rebuilt first (Category Products, Catalog Rule Product, Product EAV, Product Price and Catalog Product Rule).