From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andy Furniss Date: Thu, 17 Nov 2005 12:09:14 +0000 Subject: Re: [LARTC] Transfer speed exceeding the ceil Message-Id: <437C72EA.7010806@dsl.pipex.com> List-Id: References: <118619310511141432o4bfbde1dj9178e3c166c67039@mail.gmail.com> In-Reply-To: <118619310511141432o4bfbde1dj9178e3c166c67039@mail.gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: lartc@vger.kernel.org Ryan Castellucci wrote: > On 11/16/05, Andy Furniss wrote: > >>Ryan Castellucci wrote: >> >>>On 11/16/05, Andy Furniss wrote: >>> >>> >>>>Ryan Castellucci wrote: >>>> >>>> >>>>>What's going on here? I'm spewing UDP traffic at this thing, and it is >>>>>exceeding the ceil. Anyone know how to fix this? >>>>> >>>>>class htb 1:613 parent 1:5 leaf 613: prio 6 quantum 2560 rate 20480bit >>>>>ceil 103360bit burst 15Kb/8 mpu 0b overhead 0b cburst 1728b/8 mpu 0b >>>>>overhead 0b level 0 >>>>>Sent 16591370 bytes 4159 pkt (dropped 39449, overlimits 0 requeues 0) >>>>>rate 412384bit 6pps backlog 0b 126p requeues 0 >>>>>lended: 887 borrowed: 3146 giants: 1748 >>>>>tokens: -1605047 ctokens: -32828 >>>> >>>>Try and verify rate of udp arrival at the target machine with tcpdump -ttt. >>>> >>>>The sent counter is actually an enqueue rather than dequeue count so >>>>blatting with udp may cause bogus rates (not that I've checked how >>>>exactly htb does rate calculations). >>>> >>>>Andy. >>> >>> >>>I checked it with iftop, which confirms what tc is showing. I had >>>determined that this is an issue with fragmented packets rather then >>>specificly UDP, take a look at the other messages i posted to the >>>mailing list. is the is bug in tc/htb? or is this perhpse something >>>that could be corrected by enlarging the quantum? >> >>I tried fragged udp and it seemed OK for me - whats the mtu on the >>interface - if it's bigger than normal then try specifying it along with >>rate/ceils to htb - Looking as I type I can see giants 1748 above (I >>should have noticed that earlier) - htb does not shape big packets >>properly unless you use the mtu option. >> >>The list is down for me today. > > > I was not manualy setting the MTU. The interfaces I'm using have MTU > of 1500, but I'll try setting the MTU for my classes to 1500 and see > if that resolves the problem. Hmm - 1500 should work by default and you should see no giants - so if the mtu on the interface was 1500 I can't see how htb counted 1748 giants. Andy. _______________________________________________ LARTC mailing list LARTC@mailman.ds9a.nl http://mailman.ds9a.nl/cgi-bin/mailman/listinfo/lartc