Return-Path: X-Original-To: apmail-cassandra-user-archive@www.apache.org Delivered-To: apmail-cassandra-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 7717118156 for ; Fri, 14 Aug 2015 18:20:04 +0000 (UTC) Received: (qmail 36839 invoked by uid 500); 14 Aug 2015 18:19:57 -0000 Delivered-To: apmail-cassandra-user-archive@cassandra.apache.org Received: (qmail 36800 invoked by uid 500); 14 Aug 2015 18:19:57 -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 36790 invoked by uid 99); 14 Aug 2015 18:19:57 -0000 Received: from Unknown (HELO spamd4-us-west.apache.org) (209.188.14.142) by apache.org (qpsmtpd/0.29) with ESMTP; Fri, 14 Aug 2015 18:19:57 +0000 Received: from localhost (localhost [127.0.0.1]) by spamd4-us-west.apache.org (ASF Mail Server at spamd4-us-west.apache.org) with ESMTP id C24F8C20C8 for ; Fri, 14 Aug 2015 18:19:56 +0000 (UTC) X-Virus-Scanned: Debian amavisd-new at spamd4-us-west.apache.org X-Spam-Flag: NO X-Spam-Score: 2.911 X-Spam-Level: ** X-Spam-Status: No, score=2.911 tagged_above=-999 required=6.31 tests=[DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, HTML_MESSAGE=3, MIME_QP_LONG_LINE=0.001, SPF_PASS=-0.001, T_REMOTE_IMAGE=0.01, URIBL_BLOCKED=0.001] autolearn=disabled Authentication-Results: spamd4-us-west.apache.org (amavisd-new); dkim=pass (2048-bit key) header.d=gmail.com Received: from mx1-us-west.apache.org ([10.40.0.8]) by localhost (spamd4-us-west.apache.org [10.40.0.11]) (amavisd-new, port 10024) with ESMTP id UV_tb_PJbsoF for ; Fri, 14 Aug 2015 18:19:42 +0000 (UTC) Received: from mail-qk0-f181.google.com (mail-qk0-f181.google.com [209.85.220.181]) by mx1-us-west.apache.org (ASF Mail Server at mx1-us-west.apache.org) with ESMTPS id 6ECC9210B6 for ; Fri, 14 Aug 2015 18:19:42 +0000 (UTC) Received: by qkfj126 with SMTP id j126so28268172qkf.0 for ; Fri, 14 Aug 2015 11:19:41 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=user-agent:date:subject:from:to:message-id:thread-topic:references :in-reply-to:mime-version:content-type; bh=foZgFV+8ZMiwgpGvBzJJSq6h4vPcCK9SKswHL3V9HvE=; b=TZCU83jwkIlJa0Ysy1s3M8+9lzi1GogsDUP8sgX+xKZJHkBmURJeHhcVT2HUWX57Si tebHOO4SqxW5gy2SXNMuE5LI1hVgfLNE9++h9G/mfu9hNlV91JfqTg5Z5PtYaMLXQ9dO /FnjZG8wDZ1BQe8yFpprR6hjGXOVlRiXeQdNJaHv9BHIgw46aiAj3P0KRfzm+3Dxh/xM c+JCwFw42+RWxuzvF0+JNpDvIG9aLTSFVPuQSb9w2n7tHpLsmKdstnAioQgYJhifIg69 oolrHrxsaL/qfd+n1IqSEEEzAWCSEQbvvfhhb0XPMxdcgtAmZ2LN7Y5c93G/Bdqg+MIJ qhMA== X-Received: by 10.55.25.167 with SMTP id 39mr56079175qkz.4.1439576381605; Fri, 14 Aug 2015 11:19:41 -0700 (PDT) Received: from [192.168.11.5] ([104.192.217.99]) by smtp.gmail.com with ESMTPSA id 37sm3497680qkw.13.2015.08.14.11.19.40 for (version=TLSv1.2 cipher=ECDHE-RSA-RC4-SHA bits=128/128); Fri, 14 Aug 2015 11:19:40 -0700 (PDT) User-Agent: Microsoft-MacOutlook/0.0.0.150724 Date: Fri, 14 Aug 2015 14:19:39 -0400 Subject: Re: Configuring Cassandra to limit number of columns to read From: Russell Bradberry To: Message-ID: Thread-Topic: Configuring Cassandra to limit number of columns to read References: <4207B03C4CE8C244A7BD522A6C140D53E1EB40@EXCHANGE-01A.zepower.com> In-Reply-To: Mime-version: 1.0 Content-type: multipart/alternative; boundary="B_3522406780_551079003" > This message is in MIME format. Since your mail reader does not understand this format, some or all of this message may not be legible. --B_3522406780_551079003 Content-type: text/plain; charset="UTF-8" Content-transfer-encoding: 7bit The idea that you have 250k columns is somewhat of an anti-pattern. In this case you would typically have a few columns and many rows, then just run a select with a limit clause in your partition. From: Jonathan Haddad Reply-To: Date: Friday, August 14, 2015 at 2:16 PM To: "user@cassandra.apache.org" Subject: Re: Configuring Cassandra to limit number of columns to read 250k columns? As in, you have a CREATE TABLE statement that would have over 250K separate, typed fields? On Fri, Aug 14, 2015 at 11:07 AM Ahmed Ferdous wrote: Hi Guys, We have designed a table to have rows with large number of columns (more than 250k). One of my colleagues, mistakenly ran a select on the and that caused the nodes to go out of memory. I was just wondering if there are ways to configure Cassandra 1. To limit number of columns that can be read 2. To gracefully reject a read request if it appears to be consuming a lot of memory. Otherwise, we are leaving too much open to human mistakes. Cheers, Ahmed Ahmed Ferdous Systems Architect Corporate: 604-244-1469 Email: Ahmed.Ferdous@ze.com ZE PowerGroup Inc. 130 - 5920 No. Two Road, Richmond, BC, Canada V7C 4R9 Web: www.ze.com North America: 1-866-944-1469 Europe: 0-800-520-0193 Singapore: 800-130-1609 ZE PowerGroup Inc. Confidentiality Notice: This e-mail and any attachments are for the exclusive and confidential use of the intended recipient and contain confidential and proprietary information. If you are not the intended recipient, be aware that any reading, distribution, disclosure, copying, printing or taking action in reliance upon this e-mail is prohibited. If you have received this in error, please notify us immediately by replying to this e-mail and promptly delete this e-mail and its attachments from your computer system. --B_3522406780_551079003 Content-type: text/html; charset="UTF-8" Content-transfer-encoding: quoted-printable
The idea that you h= ave 250k columns is somewhat of an anti-pattern.  In this case you woul= d typically have a few columns and many rows, then just run a select with a = limit clause in your partition.

From: Jonathan Haddad
Reply-To: <<= a href=3D"mailto:user@cassandra.apache.org">user@cassandra.apache.org><= br>Date: Friday, August 14, 2015 at 2= :16 PM
To: "user@cassandra.apache.org"
Subject: Re: Configuring Cassandra to limit number of colu= mns to read

250k columns?   &nbs= p;As in, you have a CREATE TABLE statement that would have over 250K separat= e, typed fields?

On Fri, Au= g 14, 2015 at 11:07 AM Ahmed Ferdous <Ahmed.Ferdous@ze.com> wrote:
<= div lang=3D"EN-CA" link=3D"#0563C1" vlink=3D"#954F72">

Hi= Guys,

 

We have designed a table to have rows with large number of col= umns (more than 250k). One of my colleagues, mistakenly ran a select on the =  and that caused the nodes to go out of memory. I was just wondering if= there are ways to configure Cassandra 1. To limit number of columns that can be read 2. To gracefully = reject a read request if it appears to be consuming a lot of memory. Otherwi= se, we are leaving too much open to human mistakes.

 

Cheers,=

 

Ah= med

 

Ahmed Ferdous=
Systems Architect
Corporate: 604-244-1469     Email: Ahmed.Ferdous@ze.com

3D"2015

ZE PowerGroup Inc.
130 - 5920 No. Two Road, Richmond, BC, Canada V7C 4R9 &nbs= p;   Web: www.ze.= com
North America: 1-866-944-1469      Europe: 0-= 800-520-0193       Singapore: 800-130-160= 9

ZE PowerGroup Inc. Co= nfidentiality Notice: This e-mail and any attachments are for the exclusive = and confidential use of the intended recipient and contain confidential and = proprietary information. If you are not the intended recipient, be aware that any reading, distribution, disclosure, copying, printing or = taking action in reliance upon this e-mail is prohibited. If you have receiv= ed this in error, please notify us immediately by replying to this e-mail an= d promptly delete this e-mail and its attachments from your computer system.


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