From owner-freebsd-questions@FreeBSD.ORG Tue Jun 29 19:39:40 2004 Return-Path: Delivered-To: freebsd-questions@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id BE7BB16A4CE for ; Tue, 29 Jun 2004 19:39:40 +0000 (GMT) Received: from internet.potentialtech.com (h-66-167-251-6.phlapafg.covad.net [66.167.251.6]) by mx1.FreeBSD.org (Postfix) with ESMTP id 2C92943D2F for ; Tue, 29 Jun 2004 19:39:40 +0000 (GMT) (envelope-from wmoran@potentialtech.com) Received: from working.potentialtech.com (pa-plum-cmts1e-68-68-113-64.pittpa.adelphia.net [68.68.113.64]) by internet.potentialtech.com (Postfix) with ESMTP id 7B3DC69A39; Tue, 29 Jun 2004 15:38:56 -0400 (EDT) Date: Tue, 29 Jun 2004 15:38:55 -0400 From: Bill Moran To: Charles Swiger Message-Id: <20040629153855.300b3888.wmoran@potentialtech.com> In-Reply-To: <1187B403-C9FC-11D8-99F8-003065ABFD92@mac.com> References: <20040629140231.7b57dedf.wmoran@potentialtech.com> <1187B403-C9FC-11D8-99F8-003065ABFD92@mac.com> Organization: Potential Technologies X-Mailer: Sylpheed version 0.9.12 (GTK+ 1.2.10; i386-portbld-freebsd4.9) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit cc: questions@freebsd.org Subject: Re: REPOST: Performance problems with FTP X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 29 Jun 2004 19:39:40 -0000 Charles Swiger wrote: > On Jun 29, 2004, at 2:02 PM, Bill Moran wrote: > > I'm having some really weird problems with ftp performance on FreeBSD > > 4.10 > > that I just can't seem to figure out. > > > > My uplink here maxes out at about 35k/sec. If I scp to the machine in > > question > > I get about 30k/sec (which is expected) but when I ftp, I never get > > anything > > better than 15k/sec, and occasionally as low as 8k/sec. > [ ... ] > > I tried running the ftp daemon that ships with FreeBSD, as well as > > Proftpd and > > they both exhibit the same performance issues. > > I haven't seen any signs of such problems with 4.10. Given that you've > reproduced this using different FTP servers, it seems more likely to be > a network issue or some hardware glitch (cables? flaky NIC?) than a > software issue. I hadn't even considered hardware, becuase scp is always as fast as I would expect. I wouldn't suspect a NIC or HDD, unless the problem was consistent with _all_ file transfers, and it's not. The performance issue only occurs with FTP. If I'm wrong on this, I'd be happy to hear about it, though. > Have you asked your ISP about the issue? The ISP is my client in this case. He's asking _me_ about the issue ;) > Can you reproduce by moving ftp to a different port #? (Perhaps some > quality-of-service thingy is providing different bandwidth by port...) I haven't tried that, but I forgot to mention that a Debian box located right next to the problem box (on the same network) gets speeds equal to what would be expected. To me, that ruled out QOS, routing and other beyond-my-control Internet problems. Again, I'm happy to be corrected if there's something here I'm not aware of. > Does passive versus active FTP make a difference? Doesn't seem to. The speed seems to be about 14k/sec, regardless of active/passive. > Anything interesting in 'netstat -s'? This is just a snippet ... but it looks like an awful lot of retransmits and duplicates to me. I hadn't looked at this before, is this indicative of any particular problem? tcp: 309984 packets sent 202559 data packets (238348935 bytes) 1620 data packets (1751573 bytes) retransmitted 1 resend initiated by MTU discovery 71396 ack-only packets (1521 delayed) 0 URG only packets 49 window probe packets 21125 window update packets 13235 control packets 286171 packets received 135943 acks (for 236641220 bytes) 8830 duplicate acks 0 acks for unsent data 142183 packets (164768204 bytes) received in-sequence 215 completely duplicate packets (25524 bytes) 1 old duplicate packet 0 packets with some dup. data (0 bytes duped) 1719 out-of-order packets (2151248 bytes) 37 packets (37 bytes) of data after window 37 window probes 667 window update packets 32 packets received after close 5 discarded for bad checksums 0 discarded for bad header offset fields 0 discarded because packet too short 4613 connection requests 5160 connection accepts 19 bad connection attempts 0 listen queue overflows 9748 connections established (including accepts) 10039 connections closed (including 1656 drops) 463 connections updated cached RTT on close 463 connections updated cached RTT variance on close 132 connections updated cached ssthresh on close 22 embryonic connections dropped 90592 segments updated rtt (of 76760 attempts) 805 retransmit timeouts 9 connections dropped by rexmit timeout 54 persist timeouts 0 connections dropped by persist timeout 0 keepalive timeouts 0 keepalive probes sent 0 connections dropped by keepalive 55073 correct ACK header predictions 120750 correct data packet header predictions 5210 syncache entries added 61 retransmitted 36 dupsyn 0 dropped 5160 completed 0 bucket overflow 0 cache overflow 43 reset 7 stale 0 aborted 0 badack 0 unreach 0 zone failures 0 cookies sent 0 cookies received -- Bill Moran Potential Technologies http://www.potentialtech.com