This is also very beneficial to performance, because the daemon can process all articles without having to worry about synchronizing its internal states with other copies of innd rummaging around the news spool at the same time. However, this choice affects the overall design of the news system. Therefore, these tasks have been broken out of the main server and implemented in separate support programs. Today, NNTP is the most common means of transporting news articles around, and innd doesn't directly support anything else. Newsbatches coming in over a UUCP link, for instance, are traditionally handled by the rnews program.
Newsreaders can deliver news when a user posts an article.
Since the handling of newsreaders deserves special attention, we will come back to this a little later. When receiving an article, innd first looks up its message ID in the history file. Duplicate articles are dropped and the occurrences are optionally logged. If one or more of these groups are found in the active file, the article is filed to disk. Otherwise, it is filed to the special group junk .