[net.notes] Notes Pointers FUBARED

malcolm (08/06/82)

#N:pur-ee:13000005:000:1411
pur-ee!malcolm    Aug  5 18:29:00 1982

One of our notesfiles just got hosed up.  I tried to delete the
offending notes (reading them caused core dumps) but the pointers
were all screwed up so I finally had to remake the notesfile.

Recovering all the stuff that came in between the crash and when 
I fixed it was more difficult.  Luckily it was a local (just two machines)
newsgroup so I just resubmitted everything as one article.  This isn't possible
for the net.* articles since notes would then send them back to news and
to the rest of world.  (Imagine paying to receive the same garbage twice.)
I can't think of any way to recover network wide news.

I'm not sure what the solution is.  There are some real problems with
the lock files!!!!  Every day or two we lose a lock file and I have to
go in by hand and remove them.  There is also a note in the comments
to nfcompress saying that no one should be in the notesfile when 
the compress happens, but I can't imagine how this would screw up the
pointers.  Besides we only compress every Sunday night at 3:30AM.

I can't imagine how the pointers got screwed up.  The only time they
should change is if two processes are writing a note at the same time.
(multiple rnews at once are very common on this system).  This is the
second time this problem has happened here.

Has anybody else seen these problems, have any ideas for error
recovery, or have the time to start digging?

							Malcolm

mark (08/06/82)

It seems to me that one of the advantages of A or B news over notes
is that if something messes up, it's easier to recover because only
one UNIX file is likely to be affected, and all the UNIX tools for
manipulating files can be used to manipulate news.

Would someone please explain what the advantages of the notes method
of storing articles is?  Likewise, I'd like to know what the
advantage to the notes format of machine-to-machine transmission are.

	Mark

egb (08/07/82)

The performance on notesfiles is SIGNIFICANTLY better than
netnews. This is probably due, in part, to the one file
approach of notes. Readnews has to open many files to run
through a newsgroup while notes only opens 2 or 3 files.

On our system the performance difference is huge (UNIX 5.0).

		Ed Bradford.

(P.S. notesfiles still has its problems. I keep getting
"orphaned responses" which have very nasty crt control
sequences which puts notefiles into endless loops. Also,
I haven't figured out how to automatically add new groups
to the notesfiles yet <as this message will attest>. If
someone can answer that question please send mail.

		whuxlb!egb
		harpo!egb
		)

		Ed Bradford

malcolm (08/07/82)

#R:pur-ee:13000005:pur-ee:13000006:000:865
pur-ee!malcolm    Aug  6 20:20:00 1982

I was told that the reason to put a number of notes into a single
file was that it reduced the time for UUCP (there is a large inter-file
time) and the file space (small files are wasteful).  Unfortunately,
I can't draw any conclusions about the relative file space requirements
because of the different ways that beta news and notes expire articles.
Likewise for UUCP since I never see the articles.

I agree with you Mark....I would much rather pay a penalty in time/space
to make it a LOT easier to maintain.  I also have been pushing to have
the sequencing information moved out of a notes directory and into the
users home directory where he can edit/copy/backup the information.  I
guess the problem is how do you get access to it since notes is set
user ID.

							Malcolm
P.S.  In spite of its shortcomings I much prefer Notes over the Beta
News approach.