From user-return-60342-archive-asf-public=cust-asf.ponee.io@cassandra.apache.org Mon Mar 12 22:46:48 2018 Return-Path: X-Original-To: archive-asf-public@cust-asf.ponee.io Delivered-To: archive-asf-public@cust-asf.ponee.io Received: from mail.apache.org (hermes.apache.org [140.211.11.3]) by mx-eu-01.ponee.io (Postfix) with SMTP id CBE0018064D for ; Mon, 12 Mar 2018 22:46:47 +0100 (CET) Received: (qmail 23438 invoked by uid 500); 12 Mar 2018 21:46:45 -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 23428 invoked by uid 99); 12 Mar 2018 21:46:45 -0000 Received: from pnap-us-west-generic-nat.apache.org (HELO spamd4-us-west.apache.org) (209.188.14.142) by apache.org (qpsmtpd/0.29) with ESMTP; Mon, 12 Mar 2018 21:46:45 +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 42392C0032 for ; Mon, 12 Mar 2018 21:46:45 +0000 (UTC) X-Virus-Scanned: Debian amavisd-new at spamd4-us-west.apache.org X-Spam-Flag: NO X-Spam-Score: 1.979 X-Spam-Level: * X-Spam-Status: No, score=1.979 tagged_above=-999 required=6.31 tests=[DKIM_SIGNED=0.1, DKIM_VALID=-0.1, HTML_MESSAGE=2, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H3=-0.01, RCVD_IN_MSPIKE_WL=-0.01, SPF_PASS=-0.001] autolearn=disabled Authentication-Results: spamd4-us-west.apache.org (amavisd-new); dkim=pass (2048-bit key) header.d=instaclustr-com.20150623.gappssmtp.com Received: from mx1-lw-eu.apache.org ([10.40.0.8]) by localhost (spamd4-us-west.apache.org [10.40.0.11]) (amavisd-new, port 10024) with ESMTP id ICHmOqAPwv4l for ; Mon, 12 Mar 2018 21:46:43 +0000 (UTC) Received: from mail-yw0-f181.google.com (mail-yw0-f181.google.com [209.85.161.181]) by mx1-lw-eu.apache.org (ASF Mail Server at mx1-lw-eu.apache.org) with ESMTPS id 6B34D5F216 for ; Mon, 12 Mar 2018 21:46:42 +0000 (UTC) Received: by mail-yw0-f181.google.com with SMTP id y186so6496810ywf.7 for ; Mon, 12 Mar 2018 14:46:42 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=instaclustr-com.20150623.gappssmtp.com; s=20150623; h=mime-version:in-reply-to:references:from:date:message-id:subject:to; bh=M420/+QKCjc42mwOISt8jaZbq1mSxq2oUoDHuNMvh+M=; b=goSeTYnvf4Es5TPlUO+NqcuIL0E0lqJYhu0ikC8mCyTfQkZoE8PIj3bOeHFcATaUzj s4jsTc1r4Bg323pvH/GlcpODQRILQcde1bDxd7wWRRdWJclKMADqIyvPG3oBMTR0dapb eC4l9M7qpD2E0ipki/cLdL5vplz3HbQlUV1RJzHWHiu1JfCHz8UPp2ZvXhNKprNkZOMr 8GXDkKRlJ/uVDkX4XGqDKmdEWJhqQRSmAxwnd1xSsQLAKrQbiqCD/XoXNsrAO+03MEtB tJ7yaoxil9TZXMtOyio5/ozum4jw24atGFKVYOTSPPcgQNVO4jFMSIfqfcsRtVrtBOPE Qcfw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:in-reply-to:references:from:date :message-id:subject:to; bh=M420/+QKCjc42mwOISt8jaZbq1mSxq2oUoDHuNMvh+M=; b=uJgGLsuzNXbhFxdT6BCZ4pdyGncJ14+IVDBtUw/daWy8aluCS87eGt3U2MyAfItA67 stk8Elz0hQeVby5r+A09+q0D8y3/f2v7Hu5x1YIwpTMCDukTu72unDBBXN4Biv/aRi5O pZen6NWFpdgAazxfYB26OGrG+LUXaTjpLn/nVYMy4HfEKsKpEGoC14+MfzIErCELWVAV Y9fjDqynVHz4YFxMFVnwzR1d2osftpnG7XaWyrRl2EG0IWRUNHgJdTaNwkwy9MIioJDx yau8mP97jGnBt7faOfnicQdKCN67G4hPM9NsD1X5W9HkuyX9ftWW8j3W/b4gHLeJ6oCy 1esA== X-Gm-Message-State: AElRT7F++3YJPiR8qFxWHx9WBc4w30RGmtmUb3060IlkL2K/7zIy2QH2 HwE99syruBvlUK+a2+5gaiVVnX1I+C/KgA0VkobeQ9WP X-Google-Smtp-Source: AG47ELtMRDCtQbfBdWj5l1kywH3HYb7F0y5GQ7S6s0sggbTJy1q6D24QnoQG5nR2AB1w1N0IX+B8VThbJ+J/ZUhbWXU= X-Received: by 2002:a25:180a:: with SMTP id 10-v6mr5606840yby.465.1520891201010; Mon, 12 Mar 2018 14:46:41 -0700 (PDT) MIME-Version: 1.0 Received: by 2002:a25:b189:0:0:0:0:0 with HTTP; Mon, 12 Mar 2018 14:46:40 -0700 (PDT) In-Reply-To: References: From: Lerh Chuan Low Date: Tue, 13 Mar 2018 08:46:40 +1100 Message-ID: Subject: Re: TWCS enabling tombstone compaction To: user@cassandra.apache.org Content-Type: multipart/alternative; boundary="000000000000c7696505673e1333" --000000000000c7696505673e1333 Content-Type: text/plain; charset="UTF-8" Dear Lucas, Those properties that result in the log message you are seeing are properties common to all compaction strategies. See http://cassandra.apache. org/doc/latest/operating/compaction.html#common-options. They are *tombstone_compaction_interval *and *tombstone_threshold*. If you didn't define them when you created your table, then you will see the log message. I'm not fully certain what the intent is, but in a TWCS setting you should only rely on TTLs and not run checks for including SSTables with dropping tombstones (so it may save a little bit of computation there). DTCS has the same property, which you can find detail in this JIRA https://issues.apache. org/jira/browse/CASSANDRA-9234. You shouldn't be seeing it all the time though unless you are constantly creating and dropping tables. Hope this helps in some way :) On 10 March 2018 at 04:38, Lucas Benevides wrote: > Dear community, > > I have been using TWCS in my lab, with TTL'd data. > In the debug log there is always the sentence: > "TimeWindowCompactionStrategy.java:65 Disabling tombstone compactions for > TWCS". Indeed, the line is always repeated. > > What does it actually mean? If my data gets expired, the TWCS is already > working and purging the SSTables that become expired. It surely sound > strange to me to disable tombstone compaction. > > In the subcompaction subproperties there are only two subproperties, > compaction_window_unit and compaction_window_size. Jeff already told us > that the STCS properties also apply to TWCS, although it is not in the > documentation. > > Thanks in advance, > Lucas Benevides Dias > --000000000000c7696505673e1333 Content-Type: text/html; charset="UTF-8" Content-Transfer-Encoding: quoted-printable
Dear Lucas,=C2=A0

Those properties that result in t= he log message you are seeing are properties common to all compaction strat= egies. See=C2=A0http://cassandra.apache.= org/doc/latest/operating/compaction.html#common-options.= They are tombstone_compaction_interval and tombstone_threshold. If you didn't define them when you created your table, then you wil= l see the log message. I'm not fully certain what the intent is, but in= a TWCS setting you should only rely on TTLs and not run checks for includi= ng SSTables with dropping tombstones (so it may save a little bit of comput= ation there). DTCS has the same property, which you can find detail in this= JIRA=C2=A0https://issues.apache.org/jira/browse/CASSANDRA-923= 4.

You shouldn't be seeing it all the time though unles= s you are constantly creating and dropping tables. Hope this helps in some = way :)




On 10 March 2018 at 04:38, Lucas Benevides <= ;lucas@mau= robenevides.com.br> wrote:
=
Dear community,

I have been using TWCS = in my lab, with TTL'd data.=C2=A0
In the debug log there is a= lways the sentence: "TimeWindowCompactionStrategy.java:65=C2=A0Di= sabling tombstone compactions for TWCS". Indeed, the line is always re= peated.

What does it actually mean? If my data get= s expired, the TWCS is already working and purging the SSTables that become= expired. It surely sound strange to me to disable tombstone compaction.

In the subcompaction subproperties there are only tw= o subproperties, compaction_window_unit and compaction_window_size. Jeff al= ready told us that the STCS properties also apply to TWCS, although it is n= ot in the documentation.=C2=A0

Thanks in advance,<= /div>
Lucas Benevides Dias

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