I've written a custom search agent using jcifs (jcifs.samba.org) to access files. looking the the logs, it successfully lists all the files, saying it has 50k+ to index.
However, whenever it tries to actually index the files, it logs:
WKG-30164: Unable to open socket to host "188.8.131.52:139"
"javax.net.ssl.SSLException: Unrecognized SSL message, plaintext connection?"
WKG-30025: smb://<url>: Connection refused
I've written a test class, run on the same server, that successsfully crawls the files. So it's not a permission issue. Nor is it an issue with multiple threads; I ran my test class with an insane number of threads with no issues.