We use DirectSolrConnection via JNI in a couple of client apps that sometimes have 100s of thousands of new docs as fast as Solr will have them. It would crash relentlessly if I didn't force all calls to update or query to be on the same thread using objc's @synchronized and a message queue. I never narrowed down if this was a solr issue or a JNI one.
That doesn't sound promising. I'll throw in synchronization around the update code and see what happens. That's doesn't seem good for performance though. Can Solr as a web app handle multiple updates at once or does it synchronize to avoid it?
Thanks, Adrian Sutton http://www.symphonious.net