Return-Path: X-Original-To: archive-asf-public-internal@cust-asf2.ponee.io Delivered-To: archive-asf-public-internal@cust-asf2.ponee.io Received: from cust-asf.ponee.io (cust-asf.ponee.io [163.172.22.183]) by cust-asf2.ponee.io (Postfix) with ESMTP id 1823A200BCB for ; Thu, 24 Nov 2016 16:29:00 +0100 (CET) Received: by cust-asf.ponee.io (Postfix) id 16BF8160B1E; Thu, 24 Nov 2016 15:29:00 +0000 (UTC) Delivered-To: archive-asf-public@cust-asf.ponee.io Received: from mail.apache.org (hermes.apache.org [140.211.11.3]) by cust-asf.ponee.io (Postfix) with SMTP id 5F415160AFB for ; Thu, 24 Nov 2016 16:28:59 +0100 (CET) Received: (qmail 89138 invoked by uid 500); 24 Nov 2016 15:28:58 -0000 Mailing-List: contact commits-help@cassandra.apache.org; run by ezmlm Precedence: bulk List-Help: List-Unsubscribe: List-Post: List-Id: Reply-To: dev@cassandra.apache.org Delivered-To: mailing list commits@cassandra.apache.org Received: (qmail 89127 invoked by uid 99); 24 Nov 2016 15:28:58 -0000 Received: from arcas.apache.org (HELO arcas) (140.211.11.28) by apache.org (qpsmtpd/0.29) with ESMTP; Thu, 24 Nov 2016 15:28:58 +0000 Received: from arcas.apache.org (localhost [127.0.0.1]) by arcas (Postfix) with ESMTP id 63FE22C03DE for ; Thu, 24 Nov 2016 15:28:58 +0000 (UTC) Date: Thu, 24 Nov 2016 15:28:58 +0000 (UTC) From: "Natale Galioto (JIRA)" To: commits@cassandra.apache.org Message-ID: In-Reply-To: References: Subject: [jira] [Commented] (CASSANDRA-12907) Different data directories for SSDs and HDDs at configuration level MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit X-JIRA-FingerPrint: 30527f35849b9dde25b450d4833f0394 archived-at: Thu, 24 Nov 2016 15:29:00 -0000 [ https://issues.apache.org/jira/browse/CASSANDRA-12907?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15693538#comment-15693538 ] Natale Galioto commented on CASSANDRA-12907: -------------------------------------------- This is another option, but I was not speaking about mapping an entire CF to a specific disk, I was speaking about mapping automagically non-data files (that really needs to be fast, such as partition indexes) of *all* the CFs to a specific disk, independently on how the user configures its data directories. In my opinion, if an user have an SSD, those files should go there, no matter what, this would greatly improve the performances. Moreover it seems to me to be true for all the configurations. From the user point of view, having granularity with table metadata can be good, but "coupling" node configuration with keyspace/table configuration doesn't sound very attractive, eg adding a node with different directory naming convention could be problematic. > Different data directories for SSDs and HDDs at configuration level > ------------------------------------------------------------------- > > Key: CASSANDRA-12907 > URL: https://issues.apache.org/jira/browse/CASSANDRA-12907 > Project: Cassandra > Issue Type: Improvement > Reporter: Natale Galioto > Labels: performance > > Currently, users can speed up some CFs by symlinking its data directory to fast media such as SSDs. In my opinion, instead, configuration file should allow two different sets of directory: one dedicated to spindles, one dedicated to SSDs. > This would allow a "once and for all mixed SSD & HDD configuration", instead of continuously symlinking the "right" directory each time a CF is created (due to the name mangling of the CF directories). > And this in turn would allow a priori knowledge on disk structures, and would allow to place indexes of all sort (lookup, partition, etc... everything that is needed to "just" locate data) on fast SSDs, speeding up ALL the CFs instead of only one, while the HDDs could be used just for data retrieval and sequential reads. -- This message was sent by Atlassian JIRA (v6.3.4#6332)