We are running a Solr installation (everything standard jetty environment, just added some fields to schema).
The index is about 80k Documents that are of average si
If you only see it occasionally, and the number of documents keeps increasing, you're likely hitting the merge limit. Merging is horrendously expensive as old segments are turned into new segments, and your caches all get dumped to boot.
You definitely want to do a master/slave setup, SWAP (as seen above), etc. to smooth over the bumps.