It would be useful to see the current index heap usage (https://issues.apache.org/jira/browse/LUCENE-5197) by lucene in the LukeRequestHandler.
Add Lucene index heap size usage in the Solr admin UI
Maybe you want to open an issue to add this to the Admin UI?
Commit 1523443 from Robert Muir in branch 'dev/branches/branch_4x'
[ https://svn.apache.org/r1523443 ]
SOLR-5237: add lucene index heap usage to luke request handler
Commit 1523442 from Robert Muir in branch 'dev/trunk'
[ https://svn.apache.org/r1523442 ]
Return -1 when any of the readers are not SegmentReader
If any leaf is not a SegmentReader, i would just return -1 immediately (i think this is just adding an "else").
This would be consistent with other index statistics that sometimes arent supported.
Initial patch that adds the attribute indexHeapUsageBytes to LukeRequestHandler