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 CA646200B7F for ; Sun, 28 Aug 2016 02:52:27 +0200 (CEST) Received: by cust-asf.ponee.io (Postfix) id C46AC160AB2; Sun, 28 Aug 2016 00:52:27 +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 1923C160AB0 for ; Sun, 28 Aug 2016 02:52:26 +0200 (CEST) Received: (qmail 37190 invoked by uid 500); 28 Aug 2016 00:52:25 -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 37179 invoked by uid 99); 28 Aug 2016 00:52:25 -0000 Received: from pnap-us-west-generic-nat.apache.org (HELO spamd1-us-west.apache.org) (209.188.14.142) by apache.org (qpsmtpd/0.29) with ESMTP; Sun, 28 Aug 2016 00:52:25 +0000 Received: from localhost (localhost [127.0.0.1]) by spamd1-us-west.apache.org (ASF Mail Server at spamd1-us-west.apache.org) with ESMTP id 3AACCC23C5 for ; Sun, 28 Aug 2016 00:52:25 +0000 (UTC) X-Virus-Scanned: Debian amavisd-new at spamd1-us-west.apache.org X-Spam-Flag: NO X-Spam-Score: 1.279 X-Spam-Level: * X-Spam-Status: No, score=1.279 tagged_above=-999 required=6.31 tests=[DKIM_SIGNED=0.1, DKIM_VALID=-0.1, HTML_MESSAGE=2, RCVD_IN_DNSWL_LOW=-0.7, RCVD_IN_MSPIKE_H3=-0.01, RCVD_IN_MSPIKE_WL=-0.01, SPF_PASS=-0.001] autolearn=disabled Authentication-Results: spamd1-us-west.apache.org (amavisd-new); dkim=pass (2048-bit key) header.d=instaclustr-com.20150623.gappssmtp.com Received: from mx1-lw-us.apache.org ([10.40.0.8]) by localhost (spamd1-us-west.apache.org [10.40.0.7]) (amavisd-new, port 10024) with ESMTP id p1CH0CuUDDGI for ; Sun, 28 Aug 2016 00:52:22 +0000 (UTC) Received: from mail-wm0-f43.google.com (mail-wm0-f43.google.com [74.125.82.43]) by mx1-lw-us.apache.org (ASF Mail Server at mx1-lw-us.apache.org) with ESMTPS id D69625F46F for ; Sun, 28 Aug 2016 00:52:21 +0000 (UTC) Received: by mail-wm0-f43.google.com with SMTP id f65so35642772wmi.0 for ; Sat, 27 Aug 2016 17:52:21 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=instaclustr-com.20150623.gappssmtp.com; s=20150623; h=mime-version:from:date:message-id:subject:to; bh=cTzVxEvNwMzhRa7YdhM6c35yjVQZ14swBVTcSdaw1Eg=; b=sUFdrRRaYcn0UpFjBXpnwp50g2dBULsxgEMq6g4fsLu1BIzPCCsd4Qk2gOoqo7JAw6 somXMhOT+pnz0aq21nWJAtQwj2z2E/JgmmjIuCJ/7QblPM6L2c3AL+cGOQW3DSa6Kk7f A2KINIH0TvnWtdALT+39aYR6LSVMiIA41GlW7mZshCuotGooMRQ4I7EH9fC1g6cGmcXd Q2YVOYjhUNZYe9T3X3k7aM19OgIRgRWsV9JkKAPY5qTdseCi07959G7sKcl1iQ7063+w 8ipvBjkzl1yUJstA30ojDbO6A9g9TeBuyO6MP4mNZBSMwZStWiEzDhoQBvrp3mUO3KN+ F/Ag== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:mime-version:from:date:message-id:subject:to; bh=cTzVxEvNwMzhRa7YdhM6c35yjVQZ14swBVTcSdaw1Eg=; b=RvbaYuE9l6WRwK+am9A773xgjYizIbBoXnak+YO5+igVYJzYR3xEJ853uAvH3C+rBf c6y06Q0Gc9qW+cSQavJxLiv7CpYOwy1yRvm0BW3sn9jvufLfFRUYJhF3zSxwjJvDqtPf ijAdhPuDzT/m4eff6Lf21yH1iqg/8qwyV3cyZmYZ1hYdGqsrIca+mYrj9hqhGiE4diYA isPnTc+nTsHIe62FEHXCiYt9SPtT+uLpnpiqTTalH7jwc6jLwfneNf/SxHvVOG3ua/AA mXhlBLgHtt4WyVN3kjN9kwKaJBEoFFOAZAquEjjN17v/SesPN6n4wlvnGAlfSoOAPp/q aakA== X-Gm-Message-State: AE9vXwNSdzXiwO7pqM5w8lsD82eYBYRup2Np3rzNfZfBLFbktMMKP6Br7Et3HT4H5rJmCbFwcGHNq7C1n6619aId X-Received: by 10.28.111.4 with SMTP id k4mr4877241wmc.94.1472345535032; Sat, 27 Aug 2016 17:52:15 -0700 (PDT) MIME-Version: 1.0 Received: by 10.28.167.134 with HTTP; Sat, 27 Aug 2016 17:52:14 -0700 (PDT) From: kurt Greaves Date: Sun, 28 Aug 2016 00:52:14 +0000 Message-ID: Subject: Read Repairs and CL To: user@cassandra.apache.org Content-Type: multipart/alternative; boundary=001a1146a0dc9a44b1053b1728c2 archived-at: Sun, 28 Aug 2016 00:52:28 -0000 --001a1146a0dc9a44b1053b1728c2 Content-Type: text/plain; charset=UTF-8 Looking at the wiki for the read path ( http://wiki.apache.org/cassandra/ReadPathForUsers), in the bottom diagram for reading with a read repair, it states the following when "reading from all replica nodes" after there is a hash mismatch: If hashes do not match, do conflict resolution. First step is to read all > data from all replica nodes excluding the fastest replica (since CL=ALL) > In the bottom left of the diagram it also states: > In this example: > RF>=2 > CL=ALL > The (since CL=ALL) implies that the CL for the read during the read repair is based off the CL of the query. However I don't think that makes sense at other CLs. Anyway, I just want to clarify what CL the read for the read repair occurs at for cases where the overall query CL is not ALL. Thanks, Kurt. -- Kurt Greaves kurt@instaclustr.com www.instaclustr.com --001a1146a0dc9a44b1053b1728c2 Content-Type: text/html; charset=UTF-8 Content-Transfer-Encoding: quoted-printable
Looking at the wiki for the read path (http://wiki.apache.org/cassandra= /ReadPathForUsers), in the bottom diagram for reading with a read repai= r, it states the following when "reading from all replica nodes" = after there is a hash mismatch:

If hashes do not match, do conflict resolution. First step is= to read all data from all replica nodes excluding the fastest replica (sin= ce CL=3DALL)

=C2=A0In the bottom left o= f the diagram it also states:
In this example:
RF>=3D2
CL=3DALL

The (since CL=3DALL) implies that the CL for the read during the read re= pair is based off the CL of the query. However I don't think that makes= sense at other CLs. Anyway, I just want to clarify what CL the read for th= e read repair occurs at for cases where the overall query CL is not ALL.
Thanks,
Kurt.
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