On a Windows machine I have noticed that using a UNC path instead of a DOS path when instantiating an index writer causes the performance to slow considerably, even when the UNC is to the same location as DOS path. Is anyone aware of this and why? Is there anything that can be done to improve performance when using a UNC path?
In this example I am indexing about 3000 documents. If I instantiate IndexWriter with the path \\localhost\general\index and index the documents it takes almost 2 minutes to index these documents. If instead, I use the DOS path C:\test\general\index, which is to the exact location as the localhost UNC path, it only takes 14 seconds to index the same 3000 documents.
I realize that using the UNC path causes the involvement of the IP stack, but I'm surprised at the difference of speed. Is there anything in Lucene itself that would account for the difference in speed, or is it in the Java layer itself?
Any help would be appreciated on understanding this behavior and knowing if there is anything that can be done to bring the UNC path speed closer to the DOS path speed.