Slow EAV indexing 2.2.6, 2.2.7, 2.3.0

[jwcarder]

Most of my reindexing is fairly fast. Completing within 2 minutes or less. the catalog_product_attribute reindex is taking around 2 hours. I do have about 50 websites with a total of about 1000 configurable products and 1000 simple products. Is 2 hours the expected time for a reindex, or is there a way I can troubleshoot it to figure out what might be slowing it down?

[Sourabh Modi]

Check this file once and try returning "false" in function "isRangingNeeded"

module-catalog/Model/Indexer/Category/Product/AbstractAction.php
from:

protected function isRangingNeeded()
     {
         return true;
     }

to:

 protected function isRangingNeeded()
     {
         return false;
     }

[WebCitz]

Did you ever come across anything to improve this issue?

[WebCitz]

We have a customer with 49 websites/stores/views, 10823 products and 95 attributes. The Product EAV index was taking about 23 hours to run when it "would" complete, but typically stopped with no error message around 1 hour after moving into Magento 2.3. The only way we were able to improve the situation was truncating catalog_product_index_price and catalog_product_index_price_replica, tweaking the batching values as mentioned here https://devdocs.magento.com/guides/v2.3/extension-dev-guide/indexer-batch.html, then resetting and reindexing catalog_product_attribute. In the end, a full reindex on catalog_product_attribute was reduced from 23 hours to 58 minutes.