Reviewed: https://review.opendev.org/c/openstack/neutron/+/801310 Committed: https://opendev.org/openstack/neutron/commit/8261b67b6e6248c5cc1a4426544188e5bd9bfa03 Submitter: "Zuul (22348)" Branch: master
commit 8261b67b6e6248c5cc1a4426544188e5bd9bfa03 Author: Bence Romsics <[email protected]> Date: Mon Jul 19 15:47:51 2021 +0200 bw-limit: Pass int parameters to Open vSwitch Make sure we pass integer values to ovs when configuring bandwidth limit. This was likely working properly with Python2, and we may have missed this when migrating to Python3: https://www.python.org/dev/peps/pep-0238/ Change-Id: I2f8d974d6644657aea95302d94ca0095d70a7e62 Closes-Bug: #1936839 Co-Authored-By: Tamás Trásy <[email protected]> ** Changed in: neutron Status: In Progress => Fix Released -- You received this bug notification because you are a member of Yahoo! Engineering Team, which is subscribed to neutron. https://bugs.launchpad.net/bugs/1936839 Title: Ingress bw-limit with DPDK does not work Status in neutron: Fix Released Bug description: A colleague of mine working downstream found the following bug (his report follows with minor redactions of company-internal details). I'm going to push his proposed fix in a minute too. In short, the inbound bandwidth limitation on vHost user ports doesn't seem to work. The value set with OpenStack QoS commands on the port isn't configured properly. The problem exists in OVS backend. Creating a 1 Mbit/s limit rule: openstack network qos rule create max_1_Mbps --type bandwidth-limit --max-kbps 1000 --max-burst-kbits 1000 --ingress After applying to the port, you can query it on the compute: compute-0-5:/home/ceeinfra # ovs-vsctl list qos _uuid : c326ed8b-24ef-4f1f-a5b0-b20f3ca3297d external_ids : {id=vhu84edf6c2-f0} other_config : {cbs="125000.0", cir="125000.0"} queues : {} type : egress-policer Note: the traffic is ingress from the VM point of view, and egress from OVS. The values are not integers, they have a .0 at the end. In /var/log/openvswitch/ovs-vswitchd.log you can see that it is not accepted: 2021-07-15T12:36:23.121Z|00208|netdev_dpdk|ERR|Could not create rte meter for egress policer 2021-07-15T12:36:23.121Z|00209|netdev_dpdk|ERR|Failed to set QoS type egress-policer on port vhu84edf6c2-f0: Invalid argument 2021-07-15T12:36:23.126Z|00210|netdev_dpdk|ERR|Could not create rte meter for egress policer 2021-07-15T12:36:23.126Z|00211|netdev_dpdk|ERR|Failed to set QoS type egress-policer on port vhu84edf6c2-f0: Invalid argument If you create a traffic between two VMs, the downloading one having the limitation applied on its port reports this: root@bwtest2:~# nc 192.168.1.201 5555 | dd of=/dev/null status=progress 816316928 bytes (816 MB, 779 MiB) copied, 5 s, 163 MB/s^C 1863705+71 records in 1863738+0 records out 954233856 bytes (954 MB, 910 MiB) copied, 8.23046 s, 116 MB/s The bandwidth is higher than the set 1 Mb/s. It is possible to modify the OVS agent so it applies the bandwidth limit correctly. You have to find out where the Python scripts of the neutron_openvswitch_agent container are stored on the compute host. In our environment the file to modify is: /var/lib/docker/overlay2/68653008fca0a6434adb3985b021b2329680b71b49859c3a028f951deed59df3/merged/usr/lib/python3.6/site- packages/neutron/agent/common/ovs_lib.py In the _update_ingress_bw_limit_for_dpdk_port function, the original code is: # cir and cbs should be set in bytes instead of bits qos_other_config = { 'cir': str(max_bw_in_bits / 8), 'cbs': str(max_burst_in_bits / 8) } If you modify the code to this: # cir and cbs should be set in bytes instead of bits qos_other_config = { 'cir': str(int(max_bw_in_bits / 8)), 'cbs': str(int(max_burst_in_bits / 8)) } the values passed to OVS will be integers. You can see the difference querying the new values after applying the limit on the ports again: compute-0-5:/home/ceeinfra # ovs-vsctl list qos _uuid : b93b1165-e839-4378-a6b7-b75c13ad0d41 external_ids : {id=vhu84edf6c2-f0} other_config : {cbs="125000", cir="125000"} queues : {} type : egress-policer They don't have the .0 at the and anymore, and OVS doesn't complain in the logs about invalid arguments. The bandwidth limitation between the computes now works: root@bwtest2:~# nc 192.168.1.201 5555 | dd of=/dev/null status=progress 4095488 bytes (4.1 MB, 3.9 MiB) copied, 33 s, 123 kB/s^C 7274+1382 records in 8051+0 records out 4122112 bytes (4.1 MB, 3.9 MiB) copied, 33.4033 s, 123 kB/s 125 kB/s translates to 1 Mb/s that we have applied with the rule, so it works now. My guess is that this problem comes from the different behaviour between the division in Python2 and Python3: user@debian:~$ python2 Python 2.7.16 (default, Oct 10 2019, 22:02:15) [GCC 8.3.0] on linux2 Type "help", "copyright", "credits" or "license" for more information. >>> 4/3 1 >>> user@debian:~$ python3 Python 3.7.3 (default, Jan 22 2021, 20:04:44) [GCC 8.3.0] on linux Type "help", "copyright", "credits" or "license" for more information. >>> 4/3 1.3333333333333333 >>> Python3 doesn't round to integers, and OVS doesn't seem to accept floating point numbers. I have seen this in multiple versions. To manage notifications about this bug go to: https://bugs.launchpad.net/neutron/+bug/1936839/+subscriptions -- Mailing list: https://launchpad.net/~yahoo-eng-team Post to : [email protected] Unsubscribe : https://launchpad.net/~yahoo-eng-team More help : https://help.launchpad.net/ListHelp
