I believe my test case is flawed, so I cannot verify with certainty if the issue is fixed or not. This is the same test case as I used before, for which I posted code in a gist: https://gist.github.com/stephank/764e3414d57bc3bcb6b3
Here's what I tried: - I started two new c3.large machines from ami-69e76c1e (eu-west-1 HVM 64-bit trusty with instance store) - I downloaded io.js 1.2.0 on machine A, together with the pub.js and sub.js scripts from my gist. - I installed redis-server on machine B and reconfigured redis to bind on to the internal IP (in 10.x.x.x) - The machines were initially running linux-virtual 3.13.0.45.52. I reproduced the issue in this setup by running sub.js twice, then pub.js once on machine A, connecting them to redis on machine B. The 'rides the rocket' message showed up in the logs, and the subs lost their connection. - I enabled trusty proposed on both machines with a pin, and selectively upgraded linux-virtual on both machines. Then rebooted on both. The kernel on both machines is now linux-virtual 3.13.0.46.53. - I ran the same test again, sub.js twice, pub.js once on machine A, connecting to machine B. There were no 'rides the rocket' messages, but the subs still lose their connections. I sporadically get 'net_ratelimit: x callbacks suppressed', but not on every test run. - I disabled scather/gather on both machines, which also dropped their MTU to 1500, and ran the test again several times. There were no more 'net_ratelimit' messages, but the subs still lose their connections. - I installed redis-server on machine A the same way, listening on the internal IP, and ran the same test on machine A, but this time connecting to itself on the internal IP. The test now runs indefinitely. (But this probably doesn't touch the driver.) So I'm not sure what to take away from this. I suppose I could continue by trying to fix my test case to run properly without scather/gather, before again enabling it. Or find a way to trigger it using a different test, such as with redis-benchmark. Stefan, is it sufficient verification if your own testing now shows it fixed? -- You received this bug notification because you are a member of Kernel Packages, which is subscribed to linux in Ubuntu. https://bugs.launchpad.net/bugs/1317811 Title: Dropped packets on EC2, "xen_netfront: xennet: skb rides the rocket: x slots" Status in linux package in Ubuntu: Fix Released Status in linux source package in Trusty: Fix Committed Status in linux source package in Utopic: Fix Committed Bug description: Running Ubuntu 14.04 LTS on EC2, we see a lot of the following in the kernel log: xen_netfront: xennet: skb rides the rocket: 19 slots Each of these messages corresponds to a dropped TX packet, and eventually causes our application's connections to break and timeout. The problem appears when network load increases. We have Node.js processes doing pubsub with a Redis server, and these are most visibly affected, showing frequent connection loss. The processes talk to each other using the private addresses EC2 allocates to the machines. Notably, the default MTU on the network interface seems to have gone up from 1500 on 13.10, to 9000 in 14.04 LTS. Reducing the MTU back to 1500 seems to drastically reduce dropped packets. (Can't say for certain if it completely eliminates the problem.) The machines we run are started from ami-896c96fe. ProblemType: Bug DistroRelease: Ubuntu 14.04 Package: linux-image-3.13.0-24-generic 3.13.0-24.46 ProcVersionSignature: User Name 3.13.0-24.46-generic 3.13.9 Uname: Linux 3.13.0-24-generic x86_64 AlsaDevices: total 0 crw-rw---- 1 root audio 116, 1 May 9 09:01 seq crw-rw---- 1 root audio 116, 33 May 9 09:01 timer AplayDevices: Error: [Errno 2] No such file or directory: 'aplay' ApportVersion: 2.14.1-0ubuntu3 Architecture: amd64 ArecordDevices: Error: [Errno 2] No such file or directory: 'arecord' AudioDevicesInUse: Error: command ['fuser', '-v', '/dev/snd/seq', '/dev/snd/timer'] failed with exit code 1: CRDA: Error: [Errno 2] No such file or directory: 'iw' Date: Fri May 9 09:11:18 2014 Ec2AMI: ami-896c96fe Ec2AMIManifest: (unknown) Ec2AvailabilityZone: eu-west-1c Ec2InstanceType: c3.large Ec2Kernel: aki-52a34525 Ec2Ramdisk: unavailable IwConfig: Error: [Errno 2] No such file or directory: 'iwconfig' Lspci: Lsusb: Error: command ['lsusb'] failed with exit code 1: unable to initialize libusb: -99 PciMultimedia: ProcFB: ProcKernelCmdLine: root=LABEL=cloudimg-rootfs ro console=hvc0 RelatedPackageVersions: linux-restricted-modules-3.13.0-24-generic N/A linux-backports-modules-3.13.0-24-generic N/A linux-firmware N/A RfKill: Error: [Errno 2] No such file or directory: 'rfkill' SourcePackage: linux UpgradeStatus: No upgrade log present (probably fresh install) --- AlsaDevices: total 0 crw-rw---- 1 root audio 116, 1 May 9 09:54 seq crw-rw---- 1 root audio 116, 33 May 9 09:54 timer AplayDevices: Error: [Errno 2] No such file or directory ApportVersion: 2.14.1-0ubuntu3 Architecture: amd64 ArecordDevices: Error: [Errno 2] No such file or directory AudioDevicesInUse: Error: command ['fuser', '-v', '/dev/snd/seq', '/dev/snd/timer'] failed with exit code 1: CRDA: Error: [Errno 2] No such file or directory CurrentDmesg: [ 24.724129] init: plymouth-upstart-bridge main process ended, respawning DistroRelease: Ubuntu 14.04 Ec2AMI: ami-896c96fe Ec2AMIManifest: (unknown) Ec2AvailabilityZone: eu-west-1c Ec2InstanceType: c3.large Ec2Kernel: aki-52a34525 Ec2Ramdisk: unavailable IwConfig: Error: [Errno 2] No such file or directory Lspci: Lsusb: Error: command ['lsusb'] failed with exit code 1: unable to initialize libusb: -99 Package: linux (not installed) PciMultimedia: ProcFB: ProcKernelCmdLine: root=LABEL=cloudimg-rootfs ro console=hvc0 ProcVersionSignature: User Name 3.13.0-24.46-generic 3.13.9 RelatedPackageVersions: linux-restricted-modules-3.13.0-24-generic N/A linux-backports-modules-3.13.0-24-generic N/A linux-firmware N/A RfKill: Error: [Errno 2] No such file or directory Tags: trusty ec2-images Uname: Linux 3.13.0-24-generic x86_64 UpgradeStatus: No upgrade log present (probably fresh install) UserGroups: adm audio cdrom dialout dip floppy netdev plugdev sudo video _MarkForUpload: True break-fix: - 97a6d1bb2b658ac85ed88205ccd1ab809899884d break-fix: - 11d3d2a16cc1f05c6ece69a4392e99efb85666a6 To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1317811/+subscriptions -- Mailing list: https://launchpad.net/~kernel-packages Post to : kernel-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~kernel-packages More help : https://help.launchpad.net/ListHelp
