Date: Tue, 25 Sep 2001 14:20:10 +0900 From: tsuchiya@flab.fujitsu.co.jp To: silby@silby.com, tsuchiya@flab.fujitsu.co.jp Cc: net@FreeBSD.org Subject: Re: TCP performance question Message-ID: <200109250520.OAA00963@const.kawasaki.flab.fujitsu.co.jp>
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> > > > I tried to say that it had no effect between FreeBSD4.3 and Solaris, on my > > problem. That's what I did previously. > > > > I found discussion on "delayed ack problem"(January 24 and 25) in this > > mailing list. Though still do not understand why delayed_ack=0 does not > > work for FreeBSD and Solaris. > > > > Anyway I appreciate your helping me. > > Thank you, > > Yoshi > > If you can reproduce the problem, please take some traces with tcpdump and > post them somewhere for public consumption. Perhaps then the problem can > be found and fixed. > > Mike "Silby" Silbersack Ok, "yokan" is FreeBSD4.1.1 and I set delayed_ack=0, and "purcell" is a Solaris 2.7 box. The sending size at first is 1460+588byte and 1460+589byte later. When the size gets more than 1460+589bytes, the performance goes down. At that time, purcell begins to send acks, possibly because yokan behaves very slow. ========================== 04:54:40.136343 yokan.1238 > purcell.12354: . ack 609417 win 16060 (DF) 04:54:40.136362 purcell.12354 > yokan.1238: P 609417:610005(588) ack 610005 win 8760 (DF) 04:54:40.136386 yokan.1238 > purcell.12354: . ack 610005 win 15472 (DF) 04:54:40.136418 yokan.1238 > purcell.12354: . 610005:611465(1460) ack 610005 win 17520 (DF) 04:54:40.136430 yokan.1238 > purcell.12354: P 611465:612053(588) ack 610005 win 17520 (DF) 04:54:40.137228 purcell.12354 > yokan.1238: . 610005:611465(1460) ack 612053 win 8760 (DF) 04:54:40.137276 yokan.1238 > purcell.12354: . ack 611465 win 16060 (DF) 04:54:40.137287 purcell.12354 > yokan.1238: P 611465:612053(588) ack 612053 win 8760 (DF) 04:54:40.137311 yokan.1238 > purcell.12354: . ack 612053 win 15472 (DF) 04:54:40.137359 yokan.1238 > purcell.12354: . 612053:613513(1460) ack 612053 win 17520 (DF) 04:54:40.137370 yokan.1238 > purcell.12354: P 613513:614101(588) ack 612053 win 17520 (DF) 04:54:40.138168 purcell.12354 > yokan.1238: . 612053:613513(1460) ack 614101 win 8760 (DF) 04:54:40.138203 yokan.1238 > purcell.12354: . ack 613513 win 16060 (DF) 04:54:40.138223 purcell.12354 > yokan.1238: P 613513:614101(588) ack 614101 win 8760 (DF) 04:54:40.138245 yokan.1238 > purcell.12354: . ack 614101 win 15472 (DF) 04:54:40.138278 yokan.1238 > purcell.12354: . 614101:615561(1460) ack 614101 win 17520 (DF) 04:54:40.208029 purcell.12354 > yokan.1238: . ack 615561 win 8760 (DF) 04:54:40.208055 yokan.1238 > purcell.12354: P 615561:616150(589) ack 614101 win 17520 (DF) 04:54:40.208675 purcell.12354 > yokan.1238: . 614101:615561(1460) ack 616150 win 8760 (DF) 04:54:40.208708 yokan.1238 > purcell.12354: . ack 615561 win 16060 (DF) 04:54:40.208729 purcell.12354 > yokan.1238: P 615561:616150(589) ack 616150 win 8760 (DF) 04:54:40.208754 yokan.1238 > purcell.12354: . ack 616150 win 15471 (DF) 04:54:40.208786 yokan.1238 > purcell.12354: . 616150:617610(1460) ack 616150 win 17520 (DF) 04:54:40.278035 purcell.12354 > yokan.1238: . ack 617610 win 8760 (DF) 04:54:40.278060 yokan.1238 > purcell.12354: P 617610:618199(589) ack 616150 win 17520 (DF) 04:54:40.278678 purcell.12354 > yokan.1238: . 616150:617610(1460) ack 618199 win 8760 (DF) 04:54:40.278709 yokan.1238 > purcell.12354: . ack 617610 win 16060 (DF) 04:54:40.278731 purcell.12354 > yokan.1238: P 617610:618199(589) ack 618199 win 8760 (DF) 04:54:40.278755 yokan.1238 > purcell.12354: . ack 618199 win 16931 (DF) 04:54:40.278796 yokan.1238 > purcell.12354: . 618199:619659(1460) ack 618199 win 17520 (DF) 04:54:40.348028 purcell.12354 > yokan.1238: . ack 619659 win 8760 (DF) 04:54:40.348059 yokan.1238 > purcell.12354: P 619659:620248(589) ack 618199 win 17520 (DF) 04:54:40.348680 purcell.12354 > yokan.1238: . 618199:619659(1460) ack 620248 win 8760 (DF) 04:54:40.348711 yokan.1238 > purcell.12354: . ack 619659 win 16060 (DF) 04:54:40.348736 purcell.12354 > yokan.1238: P 619659:620248(589) ack 620248 win 8760 (DF) 04:54:40.348758 yokan.1238 > purcell.12354: . ack 620248 win 16931 (DF) 04:54:40.348795 yokan.1238 > purcell.12354: . 620248:621708(1460) ack 620248 win 17520 (DF) 04:54:40.418025 purcell.12354 > yokan.1238: . ack 621708 win 8760 (DF) ========================== And here, it's between "yokan" and another FreeBSD machine. "regulus" is a FreeBSD4.3 box, and delayed_ack=0 has been done on both of the machines. It seems they send acks normally and there is no performance slow down. ========================== 04:55:38.774912 yokan.1239 > regulus.12354: P 613513:614101(588) ack 612053 win 17520 (DF) 04:55:38.775723 regulus.12354 > yokan.1239: . ack 613513 win 16060 (DF) 04:55:38.775765 regulus.12354 > yokan.1239: . ack 614101 win 16932 (DF) 04:55:38.776424 regulus.12354 > yokan.1239: . 612053:613513(1460) ack 614101 win 17520 (DF) 04:55:38.776459 yokan.1239 > regulus.12354: . ack 613513 win 16060 (DF) 04:55:38.776479 regulus.12354 > yokan.1239: P 613513:614101(588) ack 614101 win 17520 (DF) 04:55:38.776504 yokan.1239 > regulus.12354: . ack 614101 win 15472 (DF) 04:55:38.776541 yokan.1239 > regulus.12354: . 614101:615561(1460) ack 614101 win 17520 (DF) 04:55:38.777358 regulus.12354 > yokan.1239: . ack 615561 win 16060 (DF) 04:55:38.777384 yokan.1239 > regulus.12354: P 615561:616150(589) ack 614101 win 17520 (DF) 04:55:38.777828 regulus.12354 > yokan.1239: . ack 616150 win 16931 (DF) 04:55:38.778482 regulus.12354 > yokan.1239: . 614101:615561(1460) ack 616150 win 17520 (DF) 04:55:38.778510 yokan.1239 > regulus.12354: . ack 615561 win 16060 (DF) 04:55:38.778958 regulus.12354 > yokan.1239: P 615561:616150(589) ack 616150 win 17520 (DF) 04:55:38.778984 yokan.1239 > regulus.12354: . ack 616150 win 16931 (DF) 04:55:38.779020 yokan.1239 > regulus.12354: . 616150:617610(1460) ack 616150 win 17520 (DF) 04:55:38.779835 regulus.12354 > yokan.1239: . ack 617610 win 16060 (DF) 04:55:38.779861 yokan.1239 > regulus.12354: P 617610:618199(589) ack 616150 win 17520 (DF) 04:55:38.780305 regulus.12354 > yokan.1239: . ack 618199 win 16931 (DF) 04:55:38.780959 regulus.12354 > yokan.1239: . 616150:617610(1460) ack 618199 win 17520 (DF) 04:55:38.780986 yokan.1239 > regulus.12354: . ack 617610 win 16060 (DF) 04:55:38.781435 regulus.12354 > yokan.1239: P 617610:618199(589) ack 618199 win 17520 (DF) 04:55:38.781459 yokan.1239 > regulus.12354: . ack 618199 win 16931 (DF) ========================== Thanks, Yoshi To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-net" in the body of the message
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