Configuration cleared after multiple simultaneous Atomical reindexing operations

[gburgett]

• Rails version: 5.2.1 & 5.1.6.2
• Algolia Rails integration version: 1.20.4 & 1.20.6
• Algolia Client Version: 1.23.2 & 1.26.0
• Language Version: 2.5.3p105 & 2.3.8p459

Note that this has happened in two separate apps which is why I listed two versions

Description

On occasion, we see our searchable attributes and ranking configuration cleared when we do atomical reindexing. We switched to non-atomic reindexing for a while to work around this issue but now we need atomic reindexing again and the issue is coming back.

Most recently this happened for us yesterday at 5:00 PM US Central time.

It appears that the settings were PUT twice, which leads me to believe we were running two reindexing jobs simultaneously.

Steps To Reproduce

• Open 2 rails consoles at the same time
• Execute MyModel.reindex in each, have them running simultaneously
• Observe that once finished, the searchable attributes are cleared.

[jpowell]

My vote is to prevent reindexing much like is done for a slave or replica... or even raise if the tmp index has already been created.