[Click] Packet loss with PollDevice

rchertov rchertov at cs.ucsb.edu
Thu Jan 19 14:46:47 EST 2012


On 01.19.2012 11:44, Yu Chen wrote:
> Hi Roman,
>
> I tried both. The ring buffer is always 4096 in all the experiments
> I mentioned before. However, I tried higher values with 
> txqueuelen=1000

I don't think that txqueuelen is an issue here.  You are dropping 
packets on input (PollDevice doesn't empty the ring buffer fast enough).

Roman

> only. I doubt higher values with txqueuelen will help. I will try 
> that
> combination anyway.
>
> Best Regards and Thanks,
> Yu
>
> On Thu, Jan 19, 2012 at 11:09:43AM -0800, rchertov wrote:
>> On 01.19.2012 11:06, Yu Chen wrote:
>> >1.8.0 on Linux 2.6.24.7. Yes, I played with it(from 1 to 8). 
>> However,
>>
>> Have you tried higher values like 16 and 32?  Also, since you are
>> using Intel Pro NICs, you can use ethtool to increase the RX ring
>> buffer.  ethtool -G ethX rx <SomeNumber>
>>
>> Roman
>>
>>
>> >it does not seem to help much. Yes, polldevice::count is smaller 
>> than
>> >the packets I sent to that interface. Also, the packet size 64B. I
>> >forgot
>> >to mention it in the previous emails.
>> >
>> >Best Regards and Thanks,
>> >Yu
>> >
>> >On Thu, Jan 19, 2012 at 10:59:14AM -0800, rchertov wrote:
>> >>What version of click are you running?  Also, you can play
>> >>around with
>> >>BURST parameter to PollDevice.  So are you observing that
>> >>polldevice::count is smaller than the number of packets you sent
>> >>to that
>> >>interface?
>> >>
>> >>Roman
>> >>
>> >>On 01.19.2012 10:45, Yu Chen wrote:
>> >>> Hi all,
>> >>>
>> >>> I am having an experiment with the following topology running on
>> >>> Deterlab. I
>> >>> am having a 4-core Xeon and modified e1000 driver running ore 
>> Xeon
>> >>> and modified
>> >>> e1000 driver running. The memory is 4GB.
>> >>>
>> >>> 		     User1
>> >>>                        |
>> >>> 	   User3-----Router------User4
>> >>>                        |
>> >>> 	             User2
>> >>>
>> >>> User 1 is sending packet to User 2; User 3 is sending packets
>> >>to User
>> >>> 4.
>> >>> The router only routes stuff with best effort. However, what I
>> >>> observed is
>> >>> very few losses, distributed on a small random set of rounds.
>> >>What is
>> >>> surprising is that there are losses on one particular netcard 
>> when
>> >>> the sending
>> >>> rate is only 125,000 packets/second. The loss happens at the
>> >>> receiving phase.
>> >>>
>> >>> Below is what I have tried:
>> >>> 1' I am using 4 threads, each corresponding to one pair of
>> >>PollDevice
>> >>> and
>> >>> ToDevice.
>> >>> 2' I have changed the queue length at the interface cards. I set
>> >>> txqueuelen=1
>> >>> for the senders to decrease the possible burstiness. By 
>> increasing
>> >>> the
>> >>> receiving queue length from 64 to 4096
>> >>> (the maximum queue length), the loss rate decreases.
>> >>> 3' I tried to discard the packets on their arrival at the
>> >>router. In
>> >>> this case,
>> >>> there is no observed loss.
>> >>>
>> >>> I am kind of lost at the point. Any suggestions on what can be 
>> the
>> >>> possible
>> >>> reason and what I can try next?
>> >>>
>> >>> Attached is my code.
>> >>>
>> >>> Best Regards,
>> >>> Yu
>> >>>
>> >>> Router:
>> >>>
>> >>> 
>> -----------------------------------------------------------------------
>> >>> ddressInfo(router1-w1      10.0.1.1      00:15:17:5d:16:4a,
>> >>> //eth2
>> >>> user1-w1        10.0.1.2      00:15:17:5d:29:28,      //eth0
>> >>> router1-w2      10.0.2.1      00:15:17:5d:16:48,      //eth0
>> >>> user2-w2        10.0.2.2      00:15:17:57:ce:14,      //eth0
>> >>> router1-w3      10.0.3.1      00:15:17:5d:16:4b,      //eth3
>> >>> user3-w3        10.0.3.2      00:15:17:5d:27:e8,      //eth0
>> >>> router1-w4      10.0.4.1      00:15:17:5d:16:49,      //eth1
>> >>> user4-w4        10.0.4.2      00:15:17:5d:2a:3c,      //eth0
>> >>> );
>> >>>
>> >>> c1 :: Classifier(12/0806 20/0001,
>> >>>                  12/0806 20/0002,
>> >>>                  12/0800,
>> >>>                  -);
>> >>> c2 :: Classifier(12/0806 20/0001,
>> >>>                  12/0806 20/0002,
>> >>>                  12/0800,
>> >>>                  -);
>> >>> c3 :: Classifier(12/0806 20/0001,
>> >>>                  12/0806 20/0002,
>> >>>                  12/0800,
>> >>>                  -);
>> >>> c4 :: Classifier(12/0806 20/0001,
>> >>>                  12/0806 20/0002,
>> >>>                  12/0800,
>> >>>                  -);
>> >>>
>> >>> q0 :: Discard;
>> >>> // Idle -> ToDevice(eth1);
>> >>> // Idle -> ToDevice(eth3);
>> >>> // Idle -> ToDevice(eth2);
>> >>> // Idle -> ToDevice(eth0);
>> >>> q1 :: CPUQueue(1000000) -> EtherEncap(0x0800, router1-w1,
>> >>user1-w1)
>> >>> -> td1 :: ToDevice(eth2);
>> >>> q2 :: CPUQueue(1000000) -> EtherEncap(0x0800, router1-w2,
>> >>user2-w2)
>> >>> -> td3 :: ToDevice(eth0);
>> >>> q3 :: CPUQueue(1000000) -> EtherEncap(0x0800, router1-w3,
>> >>user3-w3)
>> >>> -> td2 :: ToDevice(eth3);
>> >>> q4 :: CPUQueue(1000000) -> EtherEncap(0x0800, router1-w4,
>> >>user4-w4)
>> >>> -> td0 :: ToDevice(eth1);
>> >>>
>> >>> rt :: LookupIPRouteMP(10.0.1.0/32 0, 10.0.1.1/32 0,
>> >>10.0.1.255/32 0,
>> >>>                      10.0.2.0/32 0, 10.0.2.1/32 0,
>> >>10.0.2.255/32 0,
>> >>>                      10.0.3.0/32 0, 10.0.3.1/32 0,
>> >>10.0.3.255/32 0,
>> >>>                      10.0.4.0/32 0, 10.0.4.1/32 0,
>> >>10.0.4.255/32 0,
>> >>>                      10.0.1.0/24 1, 10.0.2.0/24 2, 10.0.3.0/24 
>> 3,
>> >>>                      10.0.4.0/24 4, 0.0.0.0/0 0);
>> >>> rt[0] -> Discard;
>> >>> rt[1] -> q1;
>> >>> rt[2] -> q2;
>> >>> rt[3] -> q3;
>> >>> rt[4] -> q4;
>> >>>
>> >>> pd1 :: PollDevice(eth2) -> c1;
>> >>> c1[0] -> q0;
>> >>> c1[1] -> q0;
>> >>> c1[2] -> DropBroadcasts -> Strip(14) -> GetIPAddress(16) -> rt;
>> >>> c1[3] -> Discard;
>> >>>
>> >>> pd3 :: PollDevice(eth0) -> c2;
>> >>> c2[0] -> q0;
>> >>> c2[1] -> q0;
>> >>> c2[2] -> DropBroadcasts -> Strip(14) -> GetIPAddress(16) -> rt;
>> >>> c2[3] -> Discard;
>> >>>
>> >>> pd2 :: PollDevice(eth3) -> c3;
>> >>> c3[0] -> q0;
>> >>> c3[1] -> q0;
>> >>> c3[2] -> DropBroadcasts -> Strip(14) -> GetIPAddress(16) -> rt;
>> >>> c3[3] -> Discard;
>> >>>
>> >>> pd0 :: PollDevice(eth1) -> c4;
>> >>> c4[0] -> q0;
>> >>> c4[1] -> q0;
>> >>> c4[2] -> DropBroadcasts -> Strip(14) -> GetIPAddress(16) -> rt;
>> >>> c4[3] -> Discard;
>> >>>
>> >>> StaticThreadSched(pd2 0, td0 0, pd0 1, td2 1, pd3 2, td1 2, pd1 
>> 3,
>> >>> td3 3);
>> >>>
>> >>> User:
>> >>> //
>> >>> AddressInfo(router1-w1      10.0.1.1      00:15:17:5d:16:4a,
>> >>> //eth2
>> >>> user1-w1        10.0.1.2      00:15:17:5d:29:28,      //eth0
>> >>> router1-w2      10.0.2.1      00:15:17:5d:16:48,      //eth0
>> >>> user2-w2        10.0.2.2      00:15:17:57:ce:14,      //eth0
>> >>> router1-w3      10.0.3.1      00:15:17:5d:16:4b,      //eth3
>> >>> user3-w3        10.0.3.2      00:15:17:5d:27:e8,      //eth0
>> >>> router1-w4      10.0.4.1      00:15:17:5d:16:49,      //eth1
>> >>> user4-w4        10.0.4.2      00:15:17:5d:2a:3c,      //eth0
>> >>> );
>> >>> //Send
>> >>> udp :: FastUDPSource(RATE 400000, LIMIT 20000000, LENGTH 78,
>> >>> 		     SRCETH user1-w1, SRCIP user1-w1, SPORT 1,
>> >>> 		     DSTETH router1-w1, DSTIP user2-w2, DPORT 1,
>> >>> 		     CHECKSUM false, INTERVAL 0, ACTIVE false)
>> >>> 	-> ToDevice(eth0);
>> >>>
>> >>> s :: Script(TYPE ACTIVE, write ctr.reset, write udp.active 
>> false,
>> >>> 	    wait 1, wait 9, write udp.active true);
>> >>>
>> >>>
>> >>> _______________________________________________
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>> >>> click at amsterdam.lcs.mit.edu
>> >>> https://amsterdam.lcs.mit.edu/mailman/listinfo/click
>> >>
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