Public bug reported: After a successful upgrade of the control-plance from Train -> Ussuri on Ubuntu Bionic, we upgraded a first compute / network node and immediately ran into issues with Neutron:
We noticed that Neutron is extremely slow in setting up and wiring the network ports, so slow it would never finish and throw all sorts of errors (RabbitMQ connection timeouts, full sync required, ...) We were now able to reproduce the error on our Ussuri DEV cloud as well: 1) First we used strace -ffff -p $PID_OF_NEUTRON_LINUXBRIDGE_AGENT and noticed that the data exchange on the unix socket between the rootwrap-daemon and the main process is really really slow. One could actually read line by line the read calls to the fd of the socket. 2) We then (after adding lots of log lines and other intensive manual debugging) used py-spy (https://github.com/benfred/py-spy) via "py-spy top --pid $PID" on the running neutron-linuxbridge-agent process and noticed all the CPU time (process was at 100% most of the time) was spent in msgpack/fallback.py 3) Since the issue was not observed in TRAIN we compared the msgpack version used and noticed that TRAIN was using version 0.5.6 while Ussuri upgraded this dependency to 0.6.2. 4) We then downgraded to version 0.5.6 of msgpack (ignoring the actual dependencies) --- cut --- apt policy python3-msgpack python3-msgpack: Installed: 0.6.2-1~cloud0 Candidate: 0.6.2-1~cloud0 Version table: *** 0.6.2-1~cloud0 500 500 http://ubuntu-cloud.archive.canonical.com/ubuntu bionic-updates/ussuri/main amd64 Packages 0.5.6-1 500 500 http://de.archive.ubuntu.com/ubuntu bionic/main amd64 Packages 100 /var/lib/dpkg/status --- cut --- vs. --- cut --- apt policy python3-msgpack python3-msgpack: Installed: 0.5.6-1 Candidate: 0.6.2-1~cloud0 Version table: 0.6.2-1~cloud0 500 500 http://ubuntu-cloud.archive.canonical.com/ubuntu bionic-updates/ussuri/main amd64 Packages *** 0.5.6-1 500 500 http://de.archive.ubuntu.com/ubuntu bionic/main amd64 Packages 100 /var/lib/dpkg/status --- cut --- and et voila: The Neutron-Linuxbridge-Agent worked just like before (building one port every few seconds) and all network ports eventually converged to ACTIVE. I could not yet spot which commit of msgpack changes (https://github.com/msgpack/msgpack-python/compare/0.5.6...v0.6.2) might have caused this issue, but I am really certain that this is a major issue for Ussuri on Ubuntu Bionic. There are "similar" issues with * https://bugs.launchpad.net/oslo.privsep/+bug/1844822 * https://bugs.launchpad.net/oslo.privsep/+bug/1896734 both related to msgpack or the size of messages exchanged. ** Affects: cloud-archive Importance: Undecided Status: New ** Affects: neutron Importance: Undecided Status: New ** Affects: oslo.privsep Importance: Undecided Status: New ** Affects: python-oslo.privsep (Ubuntu) Importance: Undecided Status: New ** Also affects: ubuntu Importance: Undecided Status: New ** Package changed: ubuntu => neutron ** Also affects: python-oslo.privsep (Ubuntu) Importance: Undecided Status: New ** Summary changed: - linuxbridge agent broken due to msgpack upgrade 0.6.2 for Ussuri on Bionic + linuxbridge agent broken due to msgpack upgrade to 0.6.2 for Ussuri on Bionic ** Summary changed: - linuxbridge agent broken due to msgpack upgrade to 0.6.2 for Ussuri on Bionic + msgpack upgrade to 0.6.2 for Ussuri on Bionic breaks linuxbridge agent ** Summary changed: - msgpack upgrade to 0.6.2 for Ussuri on Bionic breaks linuxbridge agent + msgpack upgrade to 0.6.2 breaks linuxbridge agent ** Also affects: neutron (Ubuntu) Importance: Undecided Status: New ** Description changed: After a successful upgrade of the control-plance from Train -> Ussuri on Ubuntu Bionic, we upgraded a first compute / network node and immediately ran into issues with Neutron: We noticed that Neutron is extremely slow in setting up and wiring the network ports, so slow it would never finish and throw all sorts of errors (RabbitMQ connection timeouts, full sync required, ...) - We were now able to reproduce the error on our Ussuri DEV cloud as well: - 1) First we used strace -ffff -p $PID_OF_NEUTRON_LINUXBRIDGE_AGENT and noticed that the data exchange on the unix socket between the rootwrap-daemon and the main process is really really slow. One could actually read line by line the read calls to the fd of the socket. 2) We then (after adding lots of log lines and other intensive manual debugging) used py-spy (https://github.com/benfred/py-spy) via "py-spy top --pid $PID" on the running neutron-linuxbridge-agent process and noticed all the CPU time (process was at 100% most of the time) was spent in msgpack/fallback.py 3) Since the issue was not observed in TRAIN we compared the msgpack version used and noticed that TRAIN was using version 0.5.6 while Ussuri upgraded this dependency to 0.6.2. - - 4) We then installed version 0.5.6 of msgpack (ignoring the actual dependencies) + 4) We then downgraded to version 0.5.6 of msgpack (ignoring the actual + dependencies) --- cut --- - apt policy python3-msgpack + apt policy python3-msgpack python3-msgpack: - Installed: 0.6.2-1~cloud0 + Installed: 0.6.2-1~cloud0 + Candidate: 0.6.2-1~cloud0 + Version table: + *** 0.6.2-1~cloud0 500 + 500 http://ubuntu-cloud.archive.canonical.com/ubuntu bionic-updates/ussuri/main amd64 Packages + 0.5.6-1 500 + 500 http://de.archive.ubuntu.com/ubuntu bionic/main amd64 Packages + 100 /var/lib/dpkg/status + --- cut --- + + + vs. + + --- cut --- + apt policy python3-msgpack + python3-msgpack: + Installed: 0.5.6-1 Candidate: 0.6.2-1~cloud0 Version table: - *** 0.6.2-1~cloud0 500 + 0.6.2-1~cloud0 500 500 http://ubuntu-cloud.archive.canonical.com/ubuntu bionic-updates/ussuri/main amd64 Packages - 0.5.6-1 500 + *** 0.5.6-1 500 500 http://de.archive.ubuntu.com/ubuntu bionic/main amd64 Packages 100 /var/lib/dpkg/status --- cut --- and et voila: The Neutron-Linuxbridge-Agent worked just like before (building one port every few seconds) and all network ports eventually converged to ACTIVE. - I could not yet spot which commit of msgpack changes (https://github.com/msgpack/msgpack-python/compare/0.5.6...v0.6.2) might have caused this issue, but I am really certain that this is a major issue for Ussuri on Ubuntu Bionic. - - There are "similar" issues with - * https://bugs.launchpad.net/oslo.privsep/+bug/1844822 - * https://bugs.launchpad.net/oslo.privsep/+bug/1896734 + There are "similar" issues with + * https://bugs.launchpad.net/oslo.privsep/+bug/1844822 + * https://bugs.launchpad.net/oslo.privsep/+bug/1896734 both related to msgpack or the size of messages exchanged. ** Package changed: neutron (Ubuntu) => cloud-archive -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1937261 Title: msgpack upgrade to 0.6.2 breaks linuxbridge agent To manage notifications about this bug go to: https://bugs.launchpad.net/cloud-archive/+bug/1937261/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
