This page will attempt to answer questions like the following:
– Why is Solr performance so bad?
– Why does Solr take so long to start up?
– Why is SolrCloud acting like my servers are failing when they are fine?
How much heap space do I need?
The short version: This is one of those questions that has no generic answer. You want a heap that’s large enough so that you don’t have OOME exceptions and problems