user/dev discussion of public-inbox itself
 help / color / mirror / Atom feed
From: ebiederm@xmission.com (Eric W. Biederman)
To: Eric Wong <e@80x24.org>
Cc: meta@public-inbox.org
Subject: Re: Q: Did you do something to message number recently?
Date: Tue, 25 Jun 2019 07:01:54 -0500
Message-ID: <878stpub4d.fsf@xmission.com> (raw)
In-Reply-To: <20190624234212.j7ghrejyv7ts7y2u@dcvr> (Eric Wong's message of "Mon, 24 Jun 2019 23:42:12 +0000")

Eric Wong <e@80x24.org> writes:

> "Eric W. Biederman" <ebiederm@xmission.com> wrote:
>> The add method computes the number using num_for, which uses
>> Msgmpa::mid_insert.
>> 
>> Short of the sequence number for msgmap getting scrambled I don't
>> see how that can go wrong.  Sigh.
>
> That seems to be what went wrong with "INSERT OR IGNORE"
>
> cf. https://public-inbox.org/meta/20190624233809.1721-1-e@80x24.org/

Is it INSERT OR IGNORE or is it the autoincrement?  As I read
the sqlite docs autoincrement is allowed to skip message numbers.
Especially in cases where the insert fails.

This fix should come with a test case shouldn't it?  Such a test
case should be pretty straight forward to write.  Insert a message
multiple times and then insert a new one.

I don't recall the transaction constraints on sqlite but I am wondering
if instead of INSERT OR IGNORE we should read and the increment
num_highwater in the public-inbox code and then we would not need to
depend upon autoincrement only incrementing once.  Even when the sqlite
docs don't promise it will.

>> I will have to instrument my client, and see if that will give
>> me a clue what is going on.
>
> I guess your client ends up seeing the same message
> over-and-over again like -watch does?

It usually doesn't but for dealing with a different imap server I
tweaked the code and one of the servers feeding me the last message in
the mail box every time I checked the mailbox for new messages.

I have also narrowed it down to duplication insertions.  I was just
about to start looking at what the fix would be.

>> I think most of my previous work was all in the index rebuild path.
>> Which may be why we don't have a regression test catching this.
>
> Yeah, this isn't a new bug at all.  I didn't notice since I
> mainly use w3m or (neo)mutt for NNTP and didn't look too closely
> at NNTP article numbers.  lynx makes it apparent messages are
> missing: lynx news.public-inbox.org/inbox.comp.lib.glibc.alpha

It is a little obscure in gnus but I start getting suspcious when
I tell it to give me the last 10 messages and I get only one.

Eric

  reply	other threads:[~2019-06-25 12:02 UTC|newest]

Thread overview: 9+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-06-24 15:59 Eric W. Biederman
2019-06-24 16:34 ` Eric Wong
2019-06-24 17:33   ` Eric Wong
2019-06-24 22:56     ` Eric W. Biederman
2019-06-24 23:42       ` Eric Wong
2019-06-25 12:01         ` Eric W. Biederman [this message]
2019-06-25 17:51           ` Eric Wong
2019-06-24 23:38 ` [PATCH] msgmap: mid_insert: use plain "INSERT" to detect duplicates Eric Wong
2019-06-25  3:48   ` Eric Wong

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

  List information: https://public-inbox.org/README

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=878stpub4d.fsf@xmission.com \
    --to=ebiederm@xmission.com \
    --cc=e@80x24.org \
    --cc=meta@public-inbox.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

user/dev discussion of public-inbox itself

This inbox may be cloned and mirrored by anyone:

	git clone --mirror https://public-inbox.org/meta
	git clone --mirror http://czquwvybam4bgbro.onion/meta
	git clone --mirror http://hjrcffqmbrq6wope.onion/meta
	git clone --mirror http://ou63pmih66umazou.onion/meta

	# If you have public-inbox 1.1+ installed, you may
	# initialize and index your mirror using the following commands:
	public-inbox-init -V1 meta meta/ https://public-inbox.org/meta \
		meta@public-inbox.org
	public-inbox-index meta

Example config snippet for mirrors.
Newsgroups are available over NNTP:
	nntp://news.public-inbox.org/inbox.comp.mail.public-inbox.meta
	nntp://ou63pmih66umazou.onion/inbox.comp.mail.public-inbox.meta
	nntp://czquwvybam4bgbro.onion/inbox.comp.mail.public-inbox.meta
	nntp://hjrcffqmbrq6wope.onion/inbox.comp.mail.public-inbox.meta
	nntp://news.gmane.io/gmane.mail.public-inbox.general
 note: .onion URLs require Tor: https://www.torproject.org/

code repositories for the project(s) associated with this inbox:

	https://80x24.org/public-inbox.git

AGPL code for this site: git clone https://public-inbox.org/public-inbox.git