The Stygian Mysteries of NNTP

From: Daniel F Boyd <boyd>
To: rapaport@cs.Buffalo.EDU, cs-consult@cs.Buffalo.EDU
Subject: Re: Pnews error message
Date: Sat, 25 Mar 1995 14:41:30 -0500

William J. Rapaport writes:
Yes, but what does *that* mean? Is there a problem on my machine? On some other machine? Whose file system pointer (whatever that is) is at fault? Who needs to fix it--me? you? someone else?

There's a program called INN (Improved Network News I believe) that speaks a protocol called NNTP (Network News Transfer Protocol) running, Caliban-like, on a machine in the computer center. That machine is eponymously named nntp1.acsu.buffalo.edu for tolerably obvious reasons. nntp1 has some titanic disk drives on it that store the news articles.

When you read news, your newsreader calls up nntp1 over the internet and begs the NNTP server for the articles. The server haughtily transmits the articles to your newsreader, which politely shows them to you. When you post an article, the program you're using to post makes a connection with the NNTP server and says, "Hey here's a new article that should go out." Then it helpfully sends the article.

The NNTP server on nntp1 is constantly in contact with other news servers outside the university, getting new articles from outside the university and transmitting articles originating from here to the outside world. It's also busily looking around for articles that it can throw away to reclaim disk space, which is known as expiration because typically it deletes articles that are older than a certain specified age. (What age? Available disk space divided by news-flow per day, times some fraction for safety margin, but it's also settable per group by hand.)

With this in mind, let's look at your error message again:

Check spelling, Send, Abort, Edit, or List? s
Article not accepted by server; not posted.
400 No space left on device writing article file -- throttling

The line that says "Article not accepted by server" was generated by your newsreader, informing you that nntp1 rudely rejected the article for some reason. The newsreader presumably knows about this because the response from the NNTP server said "400" at the beginning, which one would infer from context is the code number for posting failure. Then your newsreader showed you the error message that nntp1 had actually sent, which in this case was "No space left on device writing article file", which means when nntp1 went to write your article down on one of its disks, it was unable to do so because its filesystem said the "device" (i.e. disk) had no space left. Meanwhile, your newsreader, knowing that your article hadn't been posted, had saved it in a file called dead.article so you can find it again and repost it later once someone has raked through the Augean stables that are the news disks.

Nothing was wrong on your end; your newsreader worked as designed. Presumably our local Hercules has finished his diverting task and you may proceed to repost your article.

-- Dan


[send From: dschen@hydra (pts/48) at 14:43 3/25 To: boyd@hydra (pts/42)
I see you stopped at the Adverb Warehouse before coming on campus today =)
End of Message]

Daniel F. Boyd / boyd@csgeeks.org
Last modified: Sat Mar 25 14:54:55 1995