From user-return-14677-apmail-couchdb-user-archive=couchdb.apache.org@couchdb.apache.org Thu Jan 27 21:42:53 2011 Return-Path: Delivered-To: apmail-couchdb-user-archive@www.apache.org Received: (qmail 93286 invoked from network); 27 Jan 2011 21:42:52 -0000 Received: from hermes.apache.org (HELO mail.apache.org) (140.211.11.3) by minotaur.apache.org with SMTP; 27 Jan 2011 21:42:52 -0000 Received: (qmail 76669 invoked by uid 500); 27 Jan 2011 21:42:51 -0000 Delivered-To: apmail-couchdb-user-archive@couchdb.apache.org Received: (qmail 76548 invoked by uid 500); 27 Jan 2011 21:42:50 -0000 Mailing-List: contact user-help@couchdb.apache.org; run by ezmlm Precedence: bulk List-Help: List-Unsubscribe: List-Post: List-Id: Reply-To: user@couchdb.apache.org Delivered-To: mailing list user@couchdb.apache.org Received: (qmail 76540 invoked by uid 99); 27 Jan 2011 21:42:50 -0000 Received: from nike.apache.org (HELO nike.apache.org) (192.87.106.230) by apache.org (qpsmtpd/0.29) with ESMTP; Thu, 27 Jan 2011 21:42:50 +0000 X-ASF-Spam-Status: No, hits=-0.7 required=5.0 tests=FREEMAIL_FROM,RCVD_IN_DNSWL_LOW,SPF_PASS,T_TO_NO_BRKTS_FREEMAIL X-Spam-Check-By: apache.org Received-SPF: pass (nike.apache.org: domain of robert.newson@gmail.com designates 209.85.215.180 as permitted sender) Received: from [209.85.215.180] (HELO mail-ey0-f180.google.com) (209.85.215.180) by apache.org (qpsmtpd/0.29) with ESMTP; Thu, 27 Jan 2011 21:42:44 +0000 Received: by eyf18 with SMTP id 18so1189431eyf.11 for ; Thu, 27 Jan 2011 13:42:24 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:mime-version:in-reply-to:references:date :message-id:subject:from:to:content-type:content-transfer-encoding; bh=dO0D18AqrOEC5RhaOHYc2DiWCHtdcCHM/6Q83dNzCGA=; b=cPR2iXRWonmlIvmX/S6dj/rv74++GVPa6pzYd/XC0vruTsS6aNVrh56wEkzR230f9z O+GbWjBC+cVZSo61vIc/6w5lV2/I+Wf/ZBoaZXmZ5n9QaRxVbmzU29gYlpcmPYmLGQZF ZGlc48eYgP8CIX0IndyDWmkNnqXDwoEO1/uBE= 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:content-transfer-encoding; b=Xl7C2am81nKLFUOFYp8byZ4EwrsgE5Sk819R09s6SiCOlEunyR1YvSKMXxy/tv0EIV t+rjqJg9aImPgBVj1k0jxNf2YfkNsur9Htkd+9k75wWGxZ/8sJCiEZ8CzVjqjOX4h8Xf Xn6hPsG+wE+/KG823sahA0qL43jLqj+99X1HA= MIME-Version: 1.0 Received: by 10.204.71.141 with SMTP id h13mr1743304bkj.180.1296153150115; Thu, 27 Jan 2011 10:32:30 -0800 (PST) Received: by 10.204.115.134 with HTTP; Thu, 27 Jan 2011 10:32:30 -0800 (PST) In-Reply-To: References: Date: Thu, 27 Jan 2011 18:32:30 +0000 Message-ID: Subject: Re: How many databases are too many? From: Robert Newson To: user@couchdb.apache.org Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: quoted-printable X-Virus-Checked: Checked by ClamAV on apache.org The point is that idle databases are free, barring the disk space they consume. They'll be closed and paged out. It's the active set of databases that matter hence the suggestion to look at your open file descriptor limit, etc. B. On Thu, Jan 27, 2011 at 6:22 PM, Mikeal Rogers wr= ote: > I know of one server that did over a million, of course not all were > highly active. > > On Thursday, January 27, 2011, Zachary Zolton = wrote: >> Johnny, >> >> CouchDB is known to handle thousands of databases per server, but >> depending on your usage you may need to do some tweaks for the max >> number of open databases/file descriptors: >> >> http://wiki.apache.org/couchdb/Performance#Resource_Limits >> >> >> Cheers, >> >> Zach >> >> On Thu, Jan 27, 2011 at 10:06 AM, John Nelson >> wrote: >>> TLDR: Does CouchDB (conspiring with the OS?) handle thousands of databa= ses >>> well or should I use the tried-and-true-but-aggravating mapping on >>> [group_id, ...] or is there a better pattern that I am unfamiliar with? >>> >>> I'm building a web application that is group-oriented, by which I mean = that >>> each user is interested in documents produced only by the group to whic= h >>> they belong. There is no sharing of information across groups at all. >>> >>> Since these groups are completely isolated, it seems logical to house e= ach >>> one there own database but this makes the side of me familiar with RDBM= S >>> very uncomfortable. I found one blog post by John Wood which suggested = that >>> there "appears to be no =93penalty=94 for hosting many databases within= the same >>> CouchDB server." However, in my case, there would be roughly 1,000 - 5,= 000 >>> groups. From what I understand, each database is stored as the data fil= e >>> plus various index files. This would mean there are thousands of file >>> handles -- it seems like a bad idea. >>> >>> Thanks in advance, Johnny >>> >> >