Random products show out of stock until manual reindex

[AF4Q]

I have setup a new Magento store and have been adding products. I have recently noticed that some products are not showing up as out of stock on the front end despite being properly added in the admin panel (i.e. correct inventory, categories etc). Opening and saving these products a few times in the backend fixes this issue. Another way to fix this issue is manually running the reindex command from the SSH. All this time, the crons are properly running and according to the admin panel, the reindex is happening every minute.

Preconditions

1. Nginx, PHP-FPM, MariaDB, CentOS 7
2. Magento 2.2.4

Steps to reproduce

1. Add some products.
2. Some of the them will show up as out of stock.
3. Reindex manually and they will show up as in stock.

Expected result

1. Products should show up in stock without manual reindex.

Actual result

1. Products only show up in stock after manual reindex.

I have seem two similar issues on StackExchange as well and none of them have gotten a proper answer:
https://magento.stackexchange.com/questions/150656/new-products-not-showing-until-manually-reindexing-although-cron-is-running
https://magento.stackexchange.com/questions/1177/products-seemingly-randomly-disappearing-until-reindex

[FreekVandeursen]

We have a problem in our shop which might be the same issue. Once in a while products seem to disappear from the cataloginventory_stock_status table.
I have set up monitoring to check whether all enabled products have a corresponding entry in that index table. This is usually the case, but sometimes I get alerts that a number of products have disappeared from that table. And it doesn't seem to be temporary. The products only reappear in that table after a manual reindex.

So far I haven't been able to find out what circumstances will trigger this disappearing of products, although I have an unconfirmed suspicion that it has something to do with large number of products being reindex via the mview scheduled indexer.

Hi @AF4Q I cannot reproduce by your scenarious steps in clean magento , can you provide more information ?

I resolved the problem, you need to set settings for indexer on save action System->Index manager chose checkbox stock -> set to -> update on save. In my case that work

@AF4Q seems like duplicate to this -> #15939

[erikhansen]

@engcom-backlog-nazar While changing the index to "UPDATE ON SAVE" may work around the issue, Magento actually recommends using the "UPDATE BY SCHEDULE" option for production environments. Here's a quote from a Magento Support ticket where I asked for Magento's official stance on this:

When in production we always recommend UPDATE BY SCHEDULED, when in development then UPDATE ON SAVE. UPDATE BY SCHEDULE uses the crontab to run magento cron jobs which causes the indexers to run more efficiently while the store is open. So, always UPDATE BY SCHEDULE when in production but remember that means the cron tab needs to be set to run the Magento cron jobs.

@AF4Q Is your "Stock" index set to "UPDATE ON SAVE" or "UPDATE BY SCHEDULE" when you're experiencing this?

HI @AF4Q I checked this, the indexer oh state "UPDATE BY SCHEDULE" must be update partial and product may be changed. thank you for you report We've acknowledged the issue and added to our backlog.