Return-Path: Delivered-To: apmail-cassandra-user-archive@www.apache.org Received: (qmail 32504 invoked from network); 10 Feb 2011 16:00:54 -0000 Received: from hermes.apache.org (HELO mail.apache.org) (140.211.11.3) by minotaur.apache.org with SMTP; 10 Feb 2011 16:00:54 -0000 Received: (qmail 71778 invoked by uid 500); 10 Feb 2011 16:00:52 -0000 Delivered-To: apmail-cassandra-user-archive@cassandra.apache.org Received: (qmail 71217 invoked by uid 500); 10 Feb 2011 16:00:47 -0000 Mailing-List: contact user-help@cassandra.apache.org; run by ezmlm Precedence: bulk List-Help: List-Unsubscribe: List-Post: List-Id: Reply-To: user@cassandra.apache.org Delivered-To: mailing list user@cassandra.apache.org Received: (qmail 71203 invoked by uid 99); 10 Feb 2011 16:00:46 -0000 Received: from nike.apache.org (HELO nike.apache.org) (192.87.106.230) by apache.org (qpsmtpd/0.29) with ESMTP; Thu, 10 Feb 2011 16:00:46 +0000 X-ASF-Spam-Status: No, hits=-0.7 required=5.0 tests=FREEMAIL_FROM,RCVD_IN_DNSWL_LOW,SPF_PASS X-Spam-Check-By: apache.org Received-SPF: pass (nike.apache.org: domain of bill.speirs@gmail.com designates 209.85.213.172 as permitted sender) Received: from [209.85.213.172] (HELO mail-yx0-f172.google.com) (209.85.213.172) by apache.org (qpsmtpd/0.29) with ESMTP; Thu, 10 Feb 2011 16:00:39 +0000 Received: by yxt33 with SMTP id 33so720283yxt.31 for ; Thu, 10 Feb 2011 08:00:18 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:mime-version:date:message-id:subject:from:to :content-type; bh=ucQgXLoUGMF3rcd+JOzd47guF58oDA1fAgBsBJZ5D6U=; b=VQEdIuB7k20OSW94YFN6hT0YjzUS6HlhGl2lFggpPwiBtiTdZAzWqLjNKtvRDfFuP8 /xljbv9NTAbl6W5TpwbttnVGdMMW7VoXNLGeqF3d5Gw3YjfbZxWGBDoCpcf6TXu95WuH RocarA3XVYoaclndTZNQ40wkxi0lk4fSW7L5M= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:date:message-id:subject:from:to:content-type; b=KBy+Gv8rp4ZDvfQwDTpi641N5ibr19iu2JOAmxQ3UZ/VLu3FxssubDkiO8ECc5W7PI WzWa8BXiFgzmo9GtP1/eYrWJ/B5QLJVqIkXmXX4f/2Ra8u+kxErJiUdYolXF+VZX13+2 inTySV7Ksdm4lDtDXnQOJOtnPmlYBoi6sv8fM= MIME-Version: 1.0 Received: by 10.100.229.17 with SMTP id b17mr7603156anh.80.1297353618269; Thu, 10 Feb 2011 08:00:18 -0800 (PST) Received: by 10.100.46.9 with HTTP; Thu, 10 Feb 2011 08:00:18 -0800 (PST) Date: Thu, 10 Feb 2011 11:00:18 -0500 Message-ID: Subject: Super Slow Multi-gets From: Bill Speirs To: Cassandra Usergroup Content-Type: text/plain; charset=ISO-8859-1 X-Virus-Checked: Checked by ClamAV on apache.org I have a 7 node setup with a replication factor of 1 and a read consistency of 1. I have two column families: Messages which stores millions of rows with a UUID for the row key, DateIndex which stores thousands of rows with a String as the row key. I perform 2 look-ups for my queries: 1) Fetch the row from DateIndex that includes the date I'm looking for. This returns 1,000 columns where the column names are the UUID of the messages 2) Do a multi-get (Hector client) using those 1,000 row keys I got from the first query. Query 1 is taking ~300ms to fetch 1,000 columns from a single row... respectable. However, query 2 is taking over 50s to perform 1,000 row look-ups! Also, when I scale down to 100 row look-ups for query 2, the time scales in a similar fashion, down to 5s. Am I doing something wrong here? It seems like taking 5s to look-up 100 rows in a distributed hash table is way too slow. Thoughts? Bill-