debugging slowness

[Brian Whitman]

We've got periods where direct solr queries take 35s; on resin reboot  
they go back to taking 500ms. This is on a 16GB ram 4-core server. We  
want to debug this but don't know where to start. Is there some sample- 
type command we can run during queries to figure out where Solr/Lucene  
is spending its time (ala MySQL's slow query log)?