[Click] Packet loss even at low sending rate

[Bingyang Liu]

Thanks Cliff. Ya, I have tried fromdevice, and it gave worse performance. 

I think Queue should be a very mature element, and there should not be a bug there. But the experiment results told me that something got wrong. Should I use a thread safe queue instead of queue, when I use multithreads?

Thanks
Bingyang 

Sent from my iPhone

On Dec 4, 2011, at 12:31 AM, Cliff Frey <cliff at meraki.com> wrote:

> You could try FromDevice instead of PollDevice.  I'd expect that it would work fine.  If it is not high performance enough, it would be great if you should share your performance numbers just to have another datapoint.
> 
> I doubt that Queue has a bug, you could try latest click sources though just in case.  As for finding/fixing any polldevice issues, I don't have anything to help you there...
> 
> Cliff
> 
> On Sat, Dec 3, 2011 at 8:49 PM, Bingyang LIU <bjornliu at gmail.com> wrote:
> Hi Cliff,
> 
> Thank you very much for your help. I followed your suggestion and got some results. 
> 
> 1. It turned out that "PollDevice" failed to get all the packets from NIC, even if the packet sending rate is only 200kpps with the packet size of 64B. 
> 2. I used "grep . /click/.e/*/drops", all of them reported 0 drops. 
> 3. I put a counter between every two connected elements, to determine which element dropped packet. Finally I found a queue dropped packets, because the downstream counter reported less "count" than the upstream one. However, it was straight that this queue still reported 0 drops. I think there might be some bug with the element, or I mis-used the elements. 
> 
> So I have two questions. First, how can I make PollDevice work better, which means that it won't drop packets at low rate. (Should I use Stride Scheduler?) Second, is there any bug with Queue in Click 1.8.0, in terms of dropping packets without reporting the drops? 
> 
> My experiment environment and configuration: 
> * Hardware: CPU Inter Xeon X3210 (quad core at 2.13Ghz), 4GB RAM. (a server on deterlab)
> * Software: Ubuntu8.04 + Click1.8, with PollDevice and multi-thread enabled.
> * Configuration: ./configure --with-linux=/usr/src/linux-2.6.24.7 --enable-ipsec --enable-warp9 --enable-multithread=4
> * Installation: sudo click-install --thread=4 site7_router1.click
> 
> thanks!
> best 
> Bingyang
> 
> On Sat, Dec 3, 2011 at 12:42 PM, Cliff Frey <cliff at meraki.com> wrote: