From: David Bremner Date: Thu, 12 Jun 2014 22:56:34 +0000 (+2100) Subject: Re: notmuch dump: taking write-lock to protect from concurrent (cronned) notmuch... X-Git-Url: http://git.tremily.us/?a=commitdiff_plain;h=82195789e8b97ae5ebfe2edf1eb8e3159b25c999;p=notmuch-archives.git Re: notmuch dump: taking write-lock to protect from concurrent (cronned) notmuch new? --- diff --git a/70/96d7ec674908fea6dc190e8beced7e016771d4 b/70/96d7ec674908fea6dc190e8beced7e016771d4 new file mode 100644 index 000000000..6f6af8974 --- /dev/null +++ b/70/96d7ec674908fea6dc190e8beced7e016771d4 @@ -0,0 +1,82 @@ +Return-Path: +X-Original-To: notmuch@notmuchmail.org +Delivered-To: notmuch@notmuchmail.org +Received: from localhost (localhost [127.0.0.1]) + by olra.theworths.org (Postfix) with ESMTP id 5896C431FBC + for ; Thu, 12 Jun 2014 15:56:50 -0700 (PDT) +X-Virus-Scanned: Debian amavisd-new at olra.theworths.org +X-Spam-Flag: NO +X-Spam-Score: 0 +X-Spam-Level: +X-Spam-Status: No, score=0 tagged_above=-999 required=5 tests=[none] + autolearn=disabled +Received: from olra.theworths.org ([127.0.0.1]) + by localhost (olra.theworths.org [127.0.0.1]) (amavisd-new, port 10024) + with ESMTP id cb9Hyb535ZHO for ; + Thu, 12 Jun 2014 15:56:46 -0700 (PDT) +Received: from yantan.tethera.net (yantan.tethera.net [199.188.72.155]) + (using TLSv1 with cipher DHE-RSA-AES128-SHA (128/128 bits)) + (No client certificate requested) + by olra.theworths.org (Postfix) with ESMTPS id 7D719431FAF + for ; Thu, 12 Jun 2014 15:56:46 -0700 (PDT) +Received: from remotemail by yantan.tethera.net with local (Exim 4.80) + (envelope-from ) + id 1WvDvC-0000Ba-9d; Thu, 12 Jun 2014 19:56:38 -0300 +Received: (nullmailer pid 21038 invoked by uid 1000); Thu, 12 Jun 2014 + 22:56:34 -0000 +From: David Bremner +To: Mark Walters , Maarten Aertsen + , notmuch@notmuchmail.org +Subject: Re: notmuch dump: taking write-lock to protect from concurrent + (cronned) notmuch new? +In-Reply-To: <878upafegc.fsf@qmul.ac.uk> +References: <20140606080354.28047.77393@kardo.rtsn.nl> + <878upafegc.fsf@qmul.ac.uk> +User-Agent: Notmuch/0.18 (http://notmuchmail.org) Emacs/24.3.1 + (x86_64-pc-linux-gnu) +Date: Thu, 12 Jun 2014 19:56:34 -0300 +Message-ID: <87mwdhg2jh.fsf@zancas.localnet> +MIME-Version: 1.0 +Content-Type: text/plain +X-BeenThere: notmuch@notmuchmail.org +X-Mailman-Version: 2.1.13 +Precedence: list +List-Id: "Use and development of the notmuch mail system." + +List-Unsubscribe: , + +List-Archive: +List-Post: +List-Help: +List-Subscribe: , + +X-List-Received-Date: Thu, 12 Jun 2014 22:56:50 -0000 + +Mark Walters writes: + + +>> mjw1009 suggested to change NOTMUCH_DATABASE_MODE_READ_ONLY on line +>> 215 of notmuch-dump.c to NOTMUCH_DATABASE_MODE_READ_WRITE +>> +>> I'm wondering if this hits enough people to motivate the addition of a +>> command line switch (or perhaps even a change in default behaviour?) +> +> I think this is a clear bug but the fix is a little unclear. The above +> fix works but it breaks one of the tests: "unicode message-ids" in +> T150-tagging.sh. +> +> I think the problem is that it does +> notmuch dump | sed... | notmuch restore +> + +My first reaction was "argh, we should be locking things less, not +more". But then I read + + http://getting-started-with-xapian.readthedocs.org/en/latest/xapian-core-rst/admin_notes.html?highlight=backup#id10 + +and now I'm not so sure, maybe write lock for dump is the right answer. + +It seems hard to do anything sensible with "Database.reopen" in the +context of a backup. + +