What is the usage for the alerts index on all the indexer?
I install the alert manager app on search head, run the alert search on search head, also I see some alert log data on search head alerts index, but no log on indexer, so I want to know What is the usage for the alerts index on all the indexer?
If I didn't have alerts index on indexer, if it will affect the alert manager running?
if/when you have a distributed environment you should put all your indexes on indexers not a SH layer. SH layer didn't replicate index data on SH layer for that there is indexer clusters.
If you have several SH nodes and index data is some of them then Alert manager didn't work as expected as if could find only some triggered alert data based on which sh it is running and in which sh node alert has created.