Return-Path: Delivered-To: apmail-hadoop-zookeeper-user-archive@minotaur.apache.org Received: (qmail 72344 invoked from network); 20 Oct 2010 17:42:42 -0000 Received: from unknown (HELO mail.apache.org) (140.211.11.3) by 140.211.11.9 with SMTP; 20 Oct 2010 17:42:42 -0000 Received: (qmail 38521 invoked by uid 500); 20 Oct 2010 17:42:42 -0000 Delivered-To: apmail-hadoop-zookeeper-user-archive@hadoop.apache.org Received: (qmail 38478 invoked by uid 500); 20 Oct 2010 17:42:41 -0000 Mailing-List: contact zookeeper-user-help@hadoop.apache.org; run by ezmlm Precedence: bulk List-Help: List-Unsubscribe: List-Post: List-Id: Reply-To: zookeeper-user@hadoop.apache.org Delivered-To: mailing list zookeeper-user@hadoop.apache.org Received: (qmail 38470 invoked by uid 99); 20 Oct 2010 17:42:40 -0000 Received: from nike.apache.org (HELO nike.apache.org) (192.87.106.230) by apache.org (qpsmtpd/0.29) with ESMTP; Wed, 20 Oct 2010 17:42:40 +0000 X-ASF-Spam-Status: No, hits=4.4 required=10.0 tests=FREEMAIL_ENVFROM_END_DIGIT,FREEMAIL_FROM,HTML_MESSAGE,RCVD_IN_DNSWL_NONE,SPF_PASS,T_TO_NO_BRKTS_FREEMAIL X-Spam-Check-By: apache.org Received-SPF: pass (nike.apache.org: domain of phunt1@gmail.com designates 74.125.82.48 as permitted sender) Received: from [74.125.82.48] (HELO mail-ww0-f48.google.com) (74.125.82.48) by apache.org (qpsmtpd/0.29) with ESMTP; Wed, 20 Oct 2010 17:42:32 +0000 Received: by wwb18 with SMTP id 18so2999580wwb.29 for ; Wed, 20 Oct 2010 10:42:12 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:mime-version:received:received:in-reply-to :references:date:message-id:subject:from:to:content-type; bh=wc/ZMUhVQQwtDRFF/Ylkdgu4N3cXedKpFd0d9jI5/uc=; b=HJ4EKN5vJ+8e1dUenhN+gHI3HMYk2Jn9YzTqJXRdgQZrQGGrbY4xio9Q6ZSD07E46n Qq317YOXYADB9LYDYNW+fsbUVL77PWi/yLbP9ZEkIPys69L6/6CeCWMdDUf4wvNKc/R8 DQMU9bWeRafbq6wg0uWU0+KOqjyiplFAPpV4E= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :content-type; b=X+y8zDZ6jyT8BKxyjamkETqDyExhr8EX/hIUcqyrGlct+YJiBralCDAdhtMqp535DE L2M5J++d8J1Pxhiq5enk6KtdBG66U7SnFgUWWONcR7bLAH/ZBQWvxPwntnrqoIe4w/XF ZtdDwehu1OqUVhEq/cuU6x9JJ2p9LOQVk5w1g= MIME-Version: 1.0 Received: by 10.227.37.8 with SMTP id v8mr7797286wbd.37.1287596532596; Wed, 20 Oct 2010 10:42:12 -0700 (PDT) Received: by 10.227.144.15 with HTTP; Wed, 20 Oct 2010 10:42:12 -0700 (PDT) In-Reply-To: References: Date: Wed, 20 Oct 2010 10:42:12 -0700 Message-ID: Subject: Re: Retrying sequential znode creation From: Patrick Hunt To: zookeeper-user@hadoop.apache.org Content-Type: multipart/alternative; boundary=002215974c5af080dd04930fed44 X-Virus-Checked: Checked by ClamAV on apache.org --002215974c5af080dd04930fed44 Content-Type: text/plain; charset=ISO-8859-1 Hi Ted, Mahadev is in the best position to comment (he looked at it last) but iirc when we started looking into implementing this we immediately ran into so big questions. One was what to do if the logs had been cleaned up and the individual transactions no longer available. This could be overcome by changes wrt cleanup, log rotation, etc... There was another more bulletproof option, essentially to keep all the changes in memory that might be necessary to implement 22, however this might mean a significant increase in mem requirements and general bookkeeping. It turned out (again correct me if I'm wrong) that more thought was going to be necessary, esp around ensuring correct operation in any/all special cases. Patrick On Wed, Oct 13, 2010 at 12:49 PM, Ted Dunning wrote: > Patrick, > > What are these hurdles? The last comment on ZK-22 was last winter. Back > then, it didn't sound like > it was going to be that hard. > > On Wed, Oct 13, 2010 at 12:08 PM, Patrick Hunt wrote: > > > 22 would help with this issue > > https://issues.apache.org/jira/browse/ZOOKEEPER-22 > > however there are some real hurdles to implementing 22 successfully. > > > --002215974c5af080dd04930fed44--