From commits-return-206834-archive-asf-public=cust-asf.ponee.io@cassandra.apache.org Mon Feb 26 14:37:05 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 D673918064A for ; Mon, 26 Feb 2018 14:37:04 +0100 (CET) Received: (qmail 70458 invoked by uid 500); 26 Feb 2018 13:37:03 -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 70447 invoked by uid 99); 26 Feb 2018 13:37:03 -0000 Received: from pnap-us-west-generic-nat.apache.org (HELO spamd3-us-west.apache.org) (209.188.14.142) by apache.org (qpsmtpd/0.29) with ESMTP; Mon, 26 Feb 2018 13:37:03 +0000 Received: from localhost (localhost [127.0.0.1]) by spamd3-us-west.apache.org (ASF Mail Server at spamd3-us-west.apache.org) with ESMTP id 478FB180111 for ; Mon, 26 Feb 2018 13:37:03 +0000 (UTC) X-Virus-Scanned: Debian amavisd-new at spamd3-us-west.apache.org X-Spam-Flag: NO X-Spam-Score: -110.311 X-Spam-Level: X-Spam-Status: No, score=-110.311 tagged_above=-999 required=6.31 tests=[ENV_AND_HDR_SPF_MATCH=-0.5, RCVD_IN_DNSWL_MED=-2.3, SPF_PASS=-0.001, T_RP_MATCHES_RCVD=-0.01, USER_IN_DEF_SPF_WL=-7.5, USER_IN_WHITELIST=-100] autolearn=disabled Received: from mx1-lw-eu.apache.org ([10.40.0.8]) by localhost (spamd3-us-west.apache.org [10.40.0.10]) (amavisd-new, port 10024) with ESMTP id ttFpufusnbso for ; Mon, 26 Feb 2018 13:37:02 +0000 (UTC) Received: from mailrelay1-us-west.apache.org (mailrelay1-us-west.apache.org [209.188.14.139]) by mx1-lw-eu.apache.org (ASF Mail Server at mx1-lw-eu.apache.org) with ESMTP id 71F935F254 for ; Mon, 26 Feb 2018 13:37:01 +0000 (UTC) Received: from jira-lw-us.apache.org (unknown [207.244.88.139]) by mailrelay1-us-west.apache.org (ASF Mail Server at mailrelay1-us-west.apache.org) with ESMTP id 86CF3E01D8 for ; Mon, 26 Feb 2018 13:37:00 +0000 (UTC) Received: from jira-lw-us.apache.org (localhost [127.0.0.1]) by jira-lw-us.apache.org (ASF Mail Server at jira-lw-us.apache.org) with ESMTP id 0FAF2255CC for ; Mon, 26 Feb 2018 13:37:00 +0000 (UTC) Date: Mon, 26 Feb 2018 13:37:00 +0000 (UTC) From: "Nadav Har'El (JIRA)" To: commits@cassandra.apache.org Message-ID: In-Reply-To: References: Subject: [jira] [Created] (CASSANDRA-14262) View update sent multiple times during range movement MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable X-JIRA-FingerPrint: 30527f35849b9dde25b450d4833f0394 Nadav Har'El created CASSANDRA-14262: ---------------------------------------- Summary: View update sent multiple times during range movement Key: CASSANDRA-14262 URL: https://issues.apache.org/jira/browse/CASSANDRA-14262 Project: Cassandra Issue Type: Improvement Components: Materialized Views Reporter: Nadav Har'El This issue is about updating a base table with materialized views while tok= en-ranges are being moved, i.e., while a node is being added or removed fro= m the cluster (this is a long process because the data needs to be streamed= to its new owning node). During this process, each view-mutation we want to write to a view table ma= y have an additional "pending node" (or several of them) - another node (or= nodes) which will hold this view mutation, and we need to send the view mu= tations to these new nodes too. This code existed until CASSANDRA-13069, wh= en it was accidentally removed, and returned in CASSANDRA-14251. However, the current code, in mutateMV(), has each of the RF (e.g., 3) base= replicas send the view mutation to the the same pending node. This is of c= ourse redundant, and reduces write throughput while the streaming is perfor= med. I suggested (based on an idea by [~shlomi_livne]) that it may be enough for= only the single node which will be paired (when the range movement complet= es) with the pending node to send it the update. [~pauloricardomg] replied = (see=C2=A0[https://lists.apache.org/thread.html/12c78582a3f709ca33a45e5fa61= 21148b1b1ad9c9b290d1a21e4409b@%3Cdev.cassandra.apache.org%3E] ) that it app= ears that such an optimization would work in the common case of single move= ments but will not work in rarer more complex cases (I did not fully unders= tand the details, check out the above link for the details). I believe there's another problem with the current code, which is of correc= tness: If any view replica ends up with two different view rows for the sam= e partition key, such a mistake cannot currently be fixed (see CASSANDRA-10= 346). But if we have different base replicas with two different values (a c= onsistency an ordinary base repair could fix, if we ran it) and both of the= m send their update to the same pending view replica, this view replica wil= l now have two rows, one of them wrong (and cannot currently be repaired). =C2=A0 =C2=A0 =C2=A0 -- This message was sent by Atlassian JIRA (v7.6.3#76005) --------------------------------------------------------------------- To unsubscribe, e-mail: commits-unsubscribe@cassandra.apache.org For additional commands, e-mail: commits-help@cassandra.apache.org