Magento 2.1.10 contains almost 40 security fixes and functional enhancements so it will bring a lot of benefits of
your online store owner to upgrade to this latest version.
I also did that some days ago for my clients but I met a strange error.
Catalog Search indexer process unknown error: There is no such engine: mysql2
After doing some research, I figured out this process to sort out the above issue according to these steps:
# run this query UPDATE core_config_data set value = 'mysql' where path='catalog/search/engine'; # and run these commands php -f bin/magento setup:upgrade php -f bin/magento cache:flush php -f bin/magento indexer:reindex
I hope this small tip can save your time of upgrading to latest magento 2.1.10 version.