From common-dev-return-98708-archive-asf-public=cust-asf.ponee.io@hadoop.apache.org Tue Jan 9 20:21:41 2018 Return-Path: X-Original-To: archive-asf-public@eu.ponee.io Delivered-To: archive-asf-public@eu.ponee.io Received: from cust-asf.ponee.io (cust-asf.ponee.io [163.172.22.183]) by mx-eu-01.ponee.io (Postfix) with ESMTP id 10FD6180718 for ; Tue, 9 Jan 2018 20:21:41 +0100 (CET) Received: by cust-asf.ponee.io (Postfix) id 0A162160C2D; Tue, 9 Jan 2018 19:21:41 +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 50C89160C17 for ; Tue, 9 Jan 2018 20:21:40 +0100 (CET) Received: (qmail 82111 invoked by uid 500); 9 Jan 2018 19:21:39 -0000 Mailing-List: contact common-dev-help@hadoop.apache.org; run by ezmlm Precedence: bulk List-Help: List-Unsubscribe: List-Post: List-Id: Delivered-To: mailing list common-dev@hadoop.apache.org Received: (qmail 82098 invoked by uid 99); 9 Jan 2018 19:21:38 -0000 Received: from mail-relay.apache.org (HELO mail-relay.apache.org) (140.211.11.15) by apache.org (qpsmtpd/0.29) with ESMTP; Tue, 09 Jan 2018 19:21:38 +0000 Received: from mail-ua0-f172.google.com (mail-ua0-f172.google.com [209.85.217.172]) by mail-relay.apache.org (ASF Mail Server at mail-relay.apache.org) with ESMTPSA id 8EDFD1A00A0 for ; Tue, 9 Jan 2018 19:21:38 +0000 (UTC) Received: by mail-ua0-f172.google.com with SMTP id l12so9938806uaa.10 for ; Tue, 09 Jan 2018 11:21:38 -0800 (PST) X-Gm-Message-State: AKwxytcvt0b0P3XcPxn8vL1w+ZoocUIvt0HpKY92OVHPs5o9XS0qjgXr oMPJqqC+TDebWgqDCO+8oJ31iAgtyCIyOtcQz5s= X-Google-Smtp-Source: ACJfBovF+IgVXyr9mVRJJLmvEt3Zihn791uqpzNAfYi30I+X1ceOwqJjnY1T1sdOvIFC+l/67GkoOh1c1WNWCevhHj0= X-Received: by 10.176.94.165 with SMTP id y37mr15585224uag.82.1515525697573; Tue, 09 Jan 2018 11:21:37 -0800 (PST) MIME-Version: 1.0 Received: by 10.103.77.16 with HTTP; Tue, 9 Jan 2018 11:21:17 -0800 (PST) In-Reply-To: References: From: Chris Douglas Date: Tue, 9 Jan 2018 11:21:17 -0800 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: When are incompatible changes acceptable (HDFS-12990) To: larry mccay Cc: "Aaron T. Myers" , Hadoop Common Content-Type: text/plain; charset="UTF-8" Particularly since 9820 isn't in the contiguous range of ports in HDFS-9427, is there any value in this change? Let's change it back to prevent the disruption to users, but downstream projects should treat this as a bug in their tests. Please open JIRAs in affected projects. -C On Tue, Jan 9, 2018 at 5:18 AM, larry mccay wrote: > On Mon, Jan 8, 2018 at 11:28 PM, Aaron T. Myers wrote: > >> Thanks a lot for the response, Larry. Comments inline. >> >> On Mon, Jan 8, 2018 at 6:44 PM, larry mccay wrote: >> >>> Question... >>> >>> Can this be addressed in some way during or before upgrade that allows it >>> to only affect new installs? >>> Even a config based workaround prior to upgrade might make this a change >>> less disruptive. >>> >>> If part of the upgrade process includes a step (maybe even a script) to >>> set the NN RPC port explicitly beforehand then it would allow existing >>> deployments and related clients to remain whole - otherwise it will uptake >>> the new default port. >>> >> >> Perhaps something like this could be done, but I think there are downsides >> to anything like this. For example, I'm sure there are plenty of >> applications written on top of Hadoop that have tests which hard-code the >> port number. Nothing we do in a setup script will help here. If we don't >> change the default port back to what it was, these tests will likely all >> have to be updated. >> >> > > I may not have made my point clear enough. > What I meant to say is to fix the default port but direct folks to > explicitly set the port they are using in a deployment (the current > default) so that it doesn't change out from under them - unless they are > fine with it changing. > > >> >>> Meta note: we shouldn't be so pedantic about policy that we can't back >>> out something that is considered a bug or even mistake. >>> >> >> This is my bigger point. Rigidly adhering to the compat guidelines in this >> instance helps almost no one, while hurting many folks. >> >> We basically made a mistake when we decided to change the default NN port >> with little upside, even between major versions. We discovered this very >> quickly, and we have an opportunity to fix it now and in so doing likely >> disrupt very, very few users and downstream applications. If we don't >> change it, we'll be causing difficulty for our users, downstream >> developers, and ourselves, potentially for years. >> > > Agreed. > > >> >> Best, >> Aaron >> --------------------------------------------------------------------- To unsubscribe, e-mail: common-dev-unsubscribe@hadoop.apache.org For additional commands, e-mail: common-dev-help@hadoop.apache.org