From mboxrd@z Thu Jan 1 00:00:00 1970 X-Spam-Checker-Version: SpamAssassin 3.3.2 (2011-06-06) on dcvr.yhbt.net X-Spam-Level: * X-Spam-ASN: AS33070 50.56.128.0/17 X-Spam-Status: No, score=1.7 required=3.0 tests=AWL,HK_RANDOM_FROM, MSGID_FROM_MTA_HEADER,RDNS_NONE shortcircuit=no autolearn=no version=3.3.2 Path: news.gmane.org!not-for-mail From: Eric Wong Newsgroups: gmane.comp.lang.ruby.rainbows.general Subject: Re: Transfer encoding chunked disables HAProxy gzip compression Date: Fri, 2 Aug 2013 20:58:10 +0000 Message-ID: <20130802205810.GA9486@dcvr.yhbt.net> References: NNTP-Posting-Host: plane.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit X-Trace: ger.gmane.org 1375480213 1530 80.91.229.3 (2 Aug 2013 21:50:13 GMT) X-Complaints-To: usenet@ger.gmane.org NNTP-Posting-Date: Fri, 2 Aug 2013 21:50:13 +0000 (UTC) To: Rainbows! list Original-X-From: rainbows-talk-bounces-GrnCvJ7WPxnNLxjTenLetw@public.gmane.org Fri Aug 02 23:50:16 2013 Return-path: Envelope-to: gclrrg-rainbows-talk@m.gmane.org X-Original-To: rainbows-talk-GrnCvJ7WPxnNLxjTenLetw@public.gmane.org Delivered-To: rainbows-talk-GrnCvJ7WPxnNLxjTenLetw@public.gmane.org Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.21 (2010-09-15) X-BeenThere: rainbows-talk-GrnCvJ7WPxnNLxjTenLetw@public.gmane.org X-Mailman-Version: 2.1.12 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Original-Sender: rainbows-talk-bounces-GrnCvJ7WPxnNLxjTenLetw@public.gmane.org Errors-To: rainbows-talk-bounces-GrnCvJ7WPxnNLxjTenLetw@public.gmane.org X-Broken-Reverse-DNS: no host name found for IP address 50.56.192.79 Xref: news.gmane.org gmane.comp.lang.ruby.rainbows.general:501 Archived-At: Received: from [50.56.192.79] (helo=rubyforge.org) by plane.gmane.org with esmtp (Exim 4.69) (envelope-from ) id 1V5NEl-0000Vv-7e for gclrrg-rainbows-talk@m.gmane.org; Fri, 02 Aug 2013 23:50:15 +0200 Received: from localhost.localdomain (localhost [127.0.0.1]) by rubyforge.org (Postfix) with ESMTP id AD84B2E327; Fri, 2 Aug 2013 21:50:15 +0000 (UTC) Received: from dcvr.yhbt.net (dcvr.yhbt.net [64.71.152.64]) by rubyforge.org (Postfix) with ESMTP id 446182E1DA for ; Fri, 2 Aug 2013 20:58:12 +0000 (UTC) Received: from localhost (dcvr.yhbt.net [127.0.0.1]) by dcvr.yhbt.net (Postfix) with ESMTP id 7684D1F6F9; Fri, 2 Aug 2013 20:58:10 +0000 (UTC) Claudio Poli wrote: > Hello, story time. > > I was investigating why suddenly our service become slow in response > times, currenrly the app is served through Rainbows! behind HAProxy. > > It turns out that the problem is HAProxy, which we use as > frontend/load balancer *and* for gzip compression of responses from > backends. OK, hopefully these problems get fixed in HAProxy soon > So, I tried to study rainbows and unicorn internals a bit (-N switch, > -E 'development, deploy, none') to attempt and disable chunked > middleware and replace with a Rack::ContentLength, so if and when the > body can be enumerated my responses would have a fixed size length to > feed the client. > It doesn't work: I tried to place them in config.ru, in rails' > application.rb, tried the -N switch, messed with -E but in staging > every response that comes out are of type http/1.1 chunked requests. This could be from Rails chunked responses, especially if you're using -N already. You may have to dig into Rails internals a bit... When in doubt, try dropping Rails from the equation and using a bare bones "hello world" type Rack app (e.g. Rack::Lobster) Rack::ContentLength won't add a Content-Length header if the response was already chunked anywhere before. > So I went ahead and added Rack::Deflater to live with the chunked > response types and enable gzip compression as well, even if the cpu > spent time compressing moved from one load balancer to the app server. This is probably the better way to go anyways, especially if you add more Rainbows! workers and maintain few HAproxy processes. > I would like to know more about this behavior and based on which > factors Rainbows! or Unicorn set and pick the transfer-encoding or > content-lenght to use. It's down to middleware/Rack stack ordering (LIFO), and reading code of these middlewares. Since Rack::Chunked runs first in the default Rack::Server configs, Chunked can insert its headers before ContentLength for HTTP 1.1 requests. Rack::Chunked won't force an existing Content-Length response to be chunked, it'll only make things chunked that don't have either Content-Length/Transfer-Encoding set. _______________________________________________ Rainbows! mailing list - rainbows-talk-GrnCvJ7WPxnNLxjTenLetw@public.gmane.org http://rubyforge.org/mailman/listinfo/rainbows-talk Do not quote signatures (like this one) or top post when replying