Solr should log WARN log when a query requests huge rows number

We have all seen it - clients that use Integer.MAX_VALUE or 10000000 as rows parameter, to just make sure they get all possible results. And this of course leads to high GC pauses since Lucene allocates an array up front to hold results.

Solr should either log WARN when it encounters a value above a certain threshold, such as 100k (then you should use cursormark instead). Or it should simply respond with 400 error and have a system property or query parameter folks can use to override if they know what they are doing.