I'm not clear exactly what you mean by batches.
What I'm doing is: <add> <doc> <-- #1 [...] <doc> <-- #100 </add><commit/> So that's 100, in 1 HTTP POST.
Lucene sometimes just requires many file descriptors (this will be somewhat alleviated with Solr 1.2).
Is there a way to find out how many is "many" ...? /jordan