Process Manager doesn't handle exceptions properly in forked processes

[pawel-siejba]

The following bug can have fatal consequences if somebody employed any form of exception handling around indexers in their installation, as it could lead to very hard to discover bugs, that appear only on environments with several threads available, and MAGE_INDEXER_THREADS_COUNT env variable set.

Preconditions (*)

1. Magento 2.3.0 CE/EE or higher
2. Magento 2.4-develop
3. Several stores are active
4. (Optional) Elasticsearch is configured as search_engine - for ease of reproducing

Steps to reproduce (*)

1. Run MAGE_INDEXER_THREADS_COUNT=4 php bin/magento indexer:reindex catalogsearch_fulltext
2. Kill Elasticsearch process to simulate an exception thrown

Expected result (*)

1. Main process exits and the message is displayed only once, the exceptions from the forked processes are not handled as they were thrown in the main process.

Actual result (*)

1. Observe multiple Indexer failure logs and messages

xx@xx:/var/www/magento2$ MAGE_INDEXER_THREADS_COUNT=4 php bin/magento indexer:reindex catalogsearch_fulltext
Catalog Search indexer process unknown error:
Indexer handler is not available: elasticsearch7
Catalog Search indexer process unknown error:
Indexer handler is not available: elasticsearch7
Catalog Search indexer process unknown error:
Indexer handler is not available: elasticsearch7
Catalog Search indexer process unknown error:
Indexer handler is not available: elasticsearch7
Catalog Search indexer process unknown error:
Catalog Search indexer process unknown error:
Catalog Search indexer process unknown error:
Indexer handler is not available: elasticsearch7
Indexer handler is not available: elasticsearch7
Indexer handler is not available: elasticsearch7
Catalog Search indexer process unknown error:
Fail in child process

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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 @pawel-siejba. 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

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

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[pawel-siejba]

@magento I am working on this

[m2-assistant]

Hi @pawel-siejba! 👋
Thank you for collaboration. Only members of Community Contributors Team are allowed to be assigned to the issue. Please use @magento add to contributors team command to join Contributors team.

[pawel-siejba]

@magento add to contributors team

[m2-assistant]

Hi @pawel-siejba! 👋
Thank you for joining. Please accept team invitation 👉 here 👈 and add your comment one more time.

[pawel-siejba]

@magento add to contributors team

[pawel-siejba]

@magento I am working on this

[m2-assistant]

Hi @engcom-Delta. Thank you for working on this issue.
Looks like this issue is already verified and confirmed. But if you want to validate it one more time, please, go though the following instruction:

• 1. Add/Edit Component: XXXXX label(s) to the ticket, indicating the components it may be related to.
• 2. 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!
• 3. If the issue is not relevant or is not reproducible any more, feel free to close it.

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[magento-engcom-team]

✅ Confirmed by @engcom-Delta
Thank you for verifying the issue. Based on the provided information internal tickets MC-39193 were created

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

[magento-engcom-team]

Hi @pawel-siejba. Thank you for your report.
The issue has been fixed in #30626 by @pawel-siejba in 2.4-develop branch
Related commit(s):

• 5a5b6f7d4ada5ffbf55821499c547d182f8509c1

The fix will be available with the upcoming 2.4.3 release.