MDVA-13203: Magento patch: 503 error homepage post full reindex

The MDVA-13203 Magento patch fixes the issue where your site is showing a maintenance page and there are CRITICAL: SQLSTATE[23000]: Integrity constraint violation errors in the system.log. This patch is available when the Magento Quality Patch (MQP) tool 1.0.13 is installed. 

Affected products and versions

The patch is created for Magento version:
Magento Commerce Cloud 2.2.4.

Compatible with Magento versions:
Magento Commerce and Magento Commerce Cloud 2.3.0-2.4.1.

Note: the patch can be applicable to other versions. To check if the patch is compatible with your Magento version, run ./vendor/bin/magento-patches status.

Issue 

Steps to reproduce:

1. Go to the affected URL.
2. You see the maintenance page.
3. Check that the site is not in maintenance status via ssh:

php bin/magento maintenance:status
Status: maintenance mode is not active
List of exempt IP-addresses: none

4. Look at system.log:

grep critical -i var/log/system.log |tail

[2018-09-04 17:05:18] report.CRITICAL: SQLSTATE[23000]: Integrity constraint violation: 1062 Duplicate entry '4613' for key 'PRIMARY', query was: INSERT  INTO `search_tmp_5b8ebb4e994da5_88027289` (`entity_id`,`score`) VALUES (?, ?),... (?, ?), (?, ?) [] []
[2018-09-04 17:05:21] report.CRITICAL: SQLSTATE[23000]: Integrity constraint violation: 1062 Duplicate entry '4613' for key 'PRIMARY', query was: INSERT  INTO `search_tmp_5b8ebb51579943_52333638` (`entity_id`,`score`) VALUES (?, ?),...,(?, ?) [] []
[2018-09-04 17:05:47] report.CRITICAL: SQLSTATE[23000]: Integrity constraint violation: 1062 Duplicate entry '1350' for key 'PRIMARY', query was: INSERT  INTO `search_tmp_5b8ebb6b7028f4_68065024` (`entity_id`,`score`) VALUES (?, ?), (?, ?), (?, ?), (?, ?), (?, ?), (?, ?), (?, ?), (?, ?), (?, ?), (?, ?), (?, ?), (?, ?), (?, ?), (?, ?) [] []
[2018-09-04 17:05:47] report.CRITICAL: SQLSTATE[23000]: Integrity constraint violation: 1062 Duplicate entry '1350' for key 'PRIMARY', query was: INSERT  INTO `search_tmp_5b8ebb6b7885a9_23360993` (`entity_id`,`score`) VALUES (?, ?), (?, ?), (?, ?), (?, ?), (?, ?), (?, ?), (?, ?), (?, ?), (?, ?), (?, ?), (?, ?), (?, ?), (?, ?), (?, ?) [] []

date

Tue Sep  4 17:06:11 UTC 2018

Expected results:
You should see the site.

Actual results:
The maintenance page shows because of database consistency issues.

Apply the patch

For instructions on how to apply an MQP patch, use the following links depending on your Magento product:

• Magento Commerce: DevDocs Apply patches using Magento Quality Patches Tool.
• Magento Commerce Cloud: DevDocs Upgrades and Patches > Apply patches.

Related reading

To learn more about Magento Quality Patches, refer to:

•  Magento Quality Patches released: a new tool to self-serve quality patches.
•  Check if patch is available for your Magento issue using Magento Quality Patches.

For info about other patches available in MQP tool, refer to the Patches available in MQP tool section.