From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.3.2 (2011-06-06) on dcvr.yhbt.net X-Spam-Level: X-Spam-ASN: AS15169 209.85.128.0/17 X-Spam-Status: No, score=-0.2 required=3.0 tests=AWL,BAYES_00,URIBL_BLOCKED shortcircuit=no autolearn=ham version=3.3.2 X-Original-To: unicorn-public@bogomips.org Received: from mail-qa0-f52.google.com (mail-qa0-f52.google.com [209.85.216.52]) (using TLSv1 with cipher ECDHE-RSA-RC4-SHA (128/128 bits)) (No client certificate requested) by dcvr.yhbt.net (Postfix) with ESMTPS id 0AE4A1F420 for ; Tue, 22 Jul 2014 22:07:02 +0000 (UTC) Received: by mail-qa0-f52.google.com with SMTP id j15so354198qaq.11 for ; Tue, 22 Jul 2014 15:07:02 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:mime-version:in-reply-to:references:date :message-id:subject:from:to:cc:content-type; bh=ioHemJ+I7H3Brc27Csrze3zJyAUamtjBKkNqUs3C/o8=; b=BM69WEhBCIPmkJQU/zNNa4H3yW8/e+/lwMTi5bNlDCBznZUMSUqEs/2zSxhfUM4fbT QI+w/FGGF0zeXOy2zOxNJhIiqAeACLzXNNWopq9RNaTOoFY/el65YfP4UIibWa/gO/QN QCtQNvARmYRtDT75JLH1QI0Oa6+1G8wsmeKCzOByh4wHqEh5z38AC5ZO8XffO/Z1agqb v6zjeRpLHQBtiHeU9lebPx4FkO7RtxFcgxxDFdoBE6F3BlfDm7XVbrDjfyBq4WLdF8ZH E/nN7EErFKrAFhPbb86RDZ0hLGkOlbqQec5p+GZVrH1hl/cIwZrEv3XyPNpnaEPvSYaA ub4g== X-Gm-Message-State: ALoCoQn3pQzQ2UYXQMGbcvPY9voELonzd7HL+ZlNQROwXCye4n2MNTepj32uBxMWuGn9c5rHIjbO MIME-Version: 1.0 X-Received: by 10.140.81.51 with SMTP id e48mr53387679qgd.31.1406066822051; Tue, 22 Jul 2014 15:07:02 -0700 (PDT) Received: by 10.140.102.200 with HTTP; Tue, 22 Jul 2014 15:07:01 -0700 (PDT) In-Reply-To: References: <20140722205631.GA9106@dcvr.yhbt.net> Date: Tue, 22 Jul 2014 15:07:01 -0700 Message-ID: Subject: Re: High number of TCP retransmits on Solaris From: Michael Fischer To: Paul Henry Cc: Eric Wong , unicorn-public Content-Type: text/plain; charset=UTF-8 X-Content-Filtered-By: PublicInbox::Filter 0.0.1 List-Id: On Tue, Jul 22, 2014 at 2:56 PM, Paul Henry wrote: > Thanks so much! It turned out to be a separate issue entirely, one that > appears only in Solaris. When you have a high rate of connections, sockets > sit around in the TIME_WAIT state for a default of 60s. Basically, there's > a bug in Solaris that causes a new connection to be routed (based on what > chooses the ephemeral port) to an existing TIME_WAIT connection. When the > new client sends a SYN, the server responds with an ACK that has an > incorrect sequence number (intended for the old client). This causes the > client to retransmit the SYN and then the server responds correctly. Ah, you were simply running out of IP 4-tuples on the server. This isn't usually a problem in practice because client IPs are usually much more diverse. (IIRC the behavior on Linux and FreeBSD is to send an RST to the client when this happens instead of not responding to the SYN.) --Michael