| Message ID | 20220328081417.1427666-1-wintera@linux.ibm.com (mailing list archive) |
|---|---|
| Headers | show |
| Series | veth: Support bonding events | expand |
On Mon, 28 Mar 2022 10:14:16 +0200 Alexandra Winter wrote: > In case virtual instances are attached to an external network via veth > and a bridge, the interface to the external network can be a bond > interface. Bonding drivers generate specific events during failover > that trigger switch updates. When a veth device is attached to a > bridge with a bond interface, we want external switches to learn about > the veth devices as well. Can you please add an ASCII diagram of a setup your trying to describe? > Without this patch we have seen cases where recovery after bond > failover took an unacceptable amount of time (depending on timeout > settings in the network). > > Due to the symmetric nature of veth special care is required to avoid > endless notification loops. Therefore we only notify from a veth > bridgeport to a peer that is not a bridgeport. > > References: > Same handling as for macvlan: > 4c9912556867 ("macvlan: Support bonding events" > and vlan: > 4aa5dee4d999 ("net: convert resend IGMP to notifier event") When sending a single patch change you can put all the information in the commit message of the patch, the cover letter is only necessary for series of multiple patches.
On 29.03.22 04:14, Jakub Kicinski wrote: > On Mon, 28 Mar 2022 10:14:16 +0200 Alexandra Winter wrote: >> In case virtual instances are attached to an external network via veth >> and a bridge, the interface to the external network can be a bond >> interface. Bonding drivers generate specific events during failover >> that trigger switch updates. When a veth device is attached to a >> bridge with a bond interface, we want external switches to learn about >> the veth devices as well. > > Can you please add an ASCII diagram of a setup your trying to describe? | veth_a2 | veth_b2 | veth_c2 | ------o-----------o----------o------ \ | / o o o veth_a1 veth_b1 veth_c1 ------------------------- | bridge | ------------------------- bond0 / \ eth0 eth1 In case of failover from eth0 to eth1, the netdev_notifier needs to be propagated, so e.g. veth_a2 can re-announce its MAC address to the external hardware attached to eth1. Does that help? > >> Without this patch we have seen cases where recovery after bond >> failover took an unacceptable amount of time (depending on timeout >> settings in the network). >> >> Due to the symmetric nature of veth special care is required to avoid >> endless notification loops. Therefore we only notify from a veth >> bridgeport to a peer that is not a bridgeport. >> >> References: >> Same handling as for macvlan: >> 4c9912556867 ("macvlan: Support bonding events" >> and vlan: >> 4aa5dee4d999 ("net: convert resend IGMP to notifier event") > > When sending a single patch change you can put all the information > in the commit message of the patch, the cover letter is only necessary > for series of multiple patches. Thank you, I will do so in v2.
In case virtual instances are attached to an external network via veth and a bridge, the interface to the external network can be a bond interface. Bonding drivers generate specific events during failover that trigger switch updates. When a veth device is attached to a bridge with a bond interface, we want external switches to learn about the veth devices as well. Without this patch we have seen cases where recovery after bond failover took an unacceptable amount of time (depending on timeout settings in the network). Due to the symmetric nature of veth special care is required to avoid endless notification loops. Therefore we only notify from a veth bridgeport to a peer that is not a bridgeport. References: Same handling as for macvlan: 4c9912556867 ("macvlan: Support bonding events" and vlan: 4aa5dee4d999 ("net: convert resend IGMP to notifier event") Alternatives: Propagate notifier events to all ports of a bridge. IIUC, this was rejected in https://www.spinics.net/lists/netdev/msg717292.html It also seems difficult to avoid re-bouncing the notifier. Alexandra Winter (1): veth: Support bonding events drivers/net/veth.c | 53 ++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 53 insertions(+)