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 E2EFB2004C8 for ; Mon, 9 May 2016 18:24:14 +0200 (CEST) Received: by cust-asf.ponee.io (Postfix) id E1B531609A8; Mon, 9 May 2016 16:24:14 +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 251ED160A15 for ; Mon, 9 May 2016 18:24:13 +0200 (CEST) Received: (qmail 38280 invoked by uid 500); 9 May 2016 16:24:13 -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 38028 invoked by uid 99); 9 May 2016 16:24:13 -0000 Received: from arcas.apache.org (HELO arcas) (140.211.11.28) by apache.org (qpsmtpd/0.29) with ESMTP; Mon, 09 May 2016 16:24:13 +0000 Received: from arcas.apache.org (localhost [127.0.0.1]) by arcas (Postfix) with ESMTP id F25982C14F4 for ; Mon, 9 May 2016 16:24:12 +0000 (UTC) Date: Mon, 9 May 2016 16:24:12 +0000 (UTC) From: "Jeremiah Jordan (JIRA)" To: commits@cassandra.apache.org Message-ID: In-Reply-To: References: Subject: [jira] [Updated] (CASSANDRA-11738) Re-think the use of Severity in the DynamicEndpointSnitch calculation MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit X-JIRA-FingerPrint: 30527f35849b9dde25b450d4833f0394 archived-at: Mon, 09 May 2016 16:24:15 -0000 [ https://issues.apache.org/jira/browse/CASSANDRA-11738?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ] Jeremiah Jordan updated CASSANDRA-11738: ---------------------------------------- Fix Version/s: 3.x > Re-think the use of Severity in the DynamicEndpointSnitch calculation > --------------------------------------------------------------------- > > Key: CASSANDRA-11738 > URL: https://issues.apache.org/jira/browse/CASSANDRA-11738 > Project: Cassandra > Issue Type: Bug > Reporter: Jeremiah Jordan > Fix For: 3.x > > > CASSANDRA-11737 was opened to allow completely disabling the use of severity in the DynamicEndpointSnitch calculation, but that is a pretty big hammer. There is probably something we can do to better use the score. > The issue seems to be that severity is given equal weight with latency in the current code, also that severity is only based on disk io. If you have a node that is CPU bound on something (say catching up on LCS compactions because of bootstrap/repair/replace) the IO wait can be low, but the latency to the node is high. > Some ideas I had are: > 1. Allowing a yaml parameter to tune how much impact the severity score has in the calculation. > 2. Taking CPU load into account as well as IO Wait (this would probably help in the cases I have seen things go sideways) > 3. Move the -D from CASSANDRA-11737 to being a yaml level setting > 4. Go back to just relying on Latency and get rid of severity all together. Now that we have rapid read protection, maybe just using latency is enough, as it can help where the predictive nature of IO wait would have been useful. -- This message was sent by Atlassian JIRA (v6.3.4#6332)