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 ECEDFDEC1 for ; Tue, 18 Sep 2012 12:19:09 +0000 (UTC) Received: (qmail 97488 invoked by uid 500); 18 Sep 2012 12:19:09 -0000 Delivered-To: apmail-zookeeper-user-archive@zookeeper.apache.org Received: (qmail 97083 invoked by uid 500); 18 Sep 2012 12:19:06 -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 97033 invoked by uid 99); 18 Sep 2012 12:19:04 -0000 Received: from athena.apache.org (HELO athena.apache.org) (140.211.11.136) by apache.org (qpsmtpd/0.29) with ESMTP; Tue, 18 Sep 2012 12:19:04 +0000 X-ASF-Spam-Status: No, hits=1.5 required=5.0 tests=FSL_RCVD_USER,HTML_MESSAGE,RCVD_IN_DNSWL_LOW,SPF_PASS X-Spam-Check-By: apache.org Received-SPF: pass (athena.apache.org: domain of nkeywal@gmail.com designates 209.85.212.174 as permitted sender) Received: from [209.85.212.174] (HELO mail-wi0-f174.google.com) (209.85.212.174) by apache.org (qpsmtpd/0.29) with ESMTP; Tue, 18 Sep 2012 12:18:59 +0000 Received: by wibhr14 with SMTP id hr14so3138826wib.15 for ; Tue, 18 Sep 2012 05:18:38 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:in-reply-to:references:from:date:message-id:subject:to :content-type; bh=qpc2Eyw/Wzjs4lxLSx7sLCfT6RrE1tVZPK2jiMXTwkk=; b=WoXn/jDOEdgiIZIe3hlLW4joDc6Whq0S9pfuvYX5uNnHMfwCOc1qaj542F1BQekm4y lkFcZ46/9fHxEVVQW5ltyZZCkzPZulz56OtP4blv/qtCn8ZGmiJfgAIeCL5NjgTkRNO9 kNx4tGpC+e2ZY7aGoX0aj5dIXYKCerT6zlfUvB3RACmVhC0TTvZgiTYK+75bCwFvgUSE 8ZLDqEwjwPVPjzD4fpeTeL3RU/Fi7mzQ0u/LVGoi1vnB3iqu+E/7+WtPHP2K/1LIAoVU xbhOxSmbHf5Jx7JJn4dhe5qRESHsm5Ogrnz/i9ueYpMfikh5REEzdWevuMsHrMtghQH0 b9UQ== Received: by 10.216.232.84 with SMTP id m62mr7458547weq.200.1347970718538; Tue, 18 Sep 2012 05:18:38 -0700 (PDT) MIME-Version: 1.0 Received: by 10.194.81.165 with HTTP; Tue, 18 Sep 2012 05:18:18 -0700 (PDT) In-Reply-To: References: From: n keywal Date: Tue, 18 Sep 2012 14:18:18 +0200 Message-ID: Subject: Re: Some questions about Zookeeper and how it connects to NoSQL database. To: user@zookeeper.apache.org Content-Type: multipart/alternative; boundary=000e0cd51608d89c2d04c9f8e355 X-Virus-Checked: Checked by ClamAV on apache.org --000e0cd51608d89c2d04c9f8e355 Content-Type: text/plain; charset=ISO-8859-1 Hi, Your question would likely be better suited in the Cassandra mailing list. In a few words: you can, in a way, consider ZooKeeper as a database, as it persists data. But the features used are mostly the synchronisation services to manage the cluster state. So the question to your first question is 'no', so the issue mentioned in the second does not occur in practise. You can have a look at the Google paper on Big Table, it explains its role in a typical BigTable implementation. Nicolas On Tue, Sep 18, 2012 at 12:14 PM, Tuan Luu wrote: > Dear, > > I'm new to Zookeeper and I'm still not sure how it works with database > system. > > Thus I have some questions and I hope you can help me with them. > > 1. Is every server in Zookeeper system also have a copy of database? So > every time a server starts, if will connect to database and download > everything to its local memory?Or each server in Zookeeper system is also a > database itself? > > 2. What would happen if size of database is bigger then disk size of > Zookeeper server? > > 3. Is it possible for me to connect Zookeeper system to my NoSQL Cassandra > database? I really don't understand how the system will work! When a read > request comes, what is the execution flow between Zookeeper and Cassandra > database? > > Thank you very much. > > *Kind Regards,* > > *Tuan, Luu Dinh* > --000e0cd51608d89c2d04c9f8e355--