Return-Path: X-Original-To: apmail-zookeeper-user-archive@www.apache.org Delivered-To: apmail-zookeeper-user-archive@www.apache.org Received: from mail.apache.org (hermes.apache.org [140.211.11.3]) by minotaur.apache.org (Postfix) with SMTP id 98723E5CE for ; Thu, 30 May 2013 21:58:55 +0000 (UTC) Received: (qmail 93146 invoked by uid 500); 30 May 2013 21:58:54 -0000 Delivered-To: apmail-zookeeper-user-archive@zookeeper.apache.org Received: (qmail 93060 invoked by uid 500); 30 May 2013 21:58:54 -0000 Mailing-List: contact user-help@zookeeper.apache.org; run by ezmlm Precedence: bulk List-Help: List-Unsubscribe: List-Post: List-Id: Reply-To: user@zookeeper.apache.org Delivered-To: mailing list user@zookeeper.apache.org Received: (qmail 93047 invoked by uid 99); 30 May 2013 21:58:54 -0000 Received: from nike.apache.org (HELO nike.apache.org) (192.87.106.230) by apache.org (qpsmtpd/0.29) with ESMTP; Thu, 30 May 2013 21:58:54 +0000 X-ASF-Spam-Status: No, hits=2.7 required=5.0 tests=RCVD_IN_PSBL,SPF_HELO_FAIL X-Spam-Check-By: apache.org Received-SPF: error (nike.apache.org: local policy) Received: from [50.0.67.48] (HELO headquarters.firelightfoundation.org) (50.0.67.48) by apache.org (qpsmtpd/0.29) with ESMTP; Thu, 30 May 2013 21:58:46 +0000 Received: from nimbus-sf.juniper.net (c-76-18-70-23.hsd1.nm.comcast.net [76.18.70.23]) by headquarters.firelightfoundation.org (Postfix) with ESMTPA id 95D1673D9391 for ; Thu, 30 May 2013 14:57:47 -0700 (PDT) From: Dave Katz Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: quoted-printable Subject: Detecting data loss Message-Id: Date: Thu, 30 May 2013 15:57:38 -0600 To: "user@zookeeper.apache.org" Mime-Version: 1.0 (Mac OS X Mail 6.3 \(1503\)) X-Mailer: Apple Mail (2.1503) X-Virus-Checked: Checked by ClamAV on apache.org Are there any hooks by which the Zookeeper server can signal that it has = lost data? It seems at least theoretically possible that when a server = is reconciling its state with other servers that it could detect history = truncation and signal it (even as crudely as throwing an exception). = This would provide a mechanism with which an elastic system could do = last-ditch recovery when things fell apart. Thanks, --Dave