Hi I'm interested to one Docker issue[1] which looks like related to kernel vxlan socket creation as described in the thread. From my limited knowledge here, socket creation is synchronous , and after the *socket* syscall, the sock handle will be valid and ready to linkup.
Somehow I'm not sure the detailed scenario here, and which/how possible commit fix? Thanks! Quoted analysis: -------------------------------------------------------------------------- (Found in kernel 3.13) The issue happens because in older kernels when a vxlan interface is created, the socket creation is queued up in a worker thread which actually creates the socket. But this needs to happen before we bring up the link on the vxlan interface. If for some chance, the worker thread hasn't completed the creation of the socket before we did link up then when we do link up the kernel checks if the socket was created and if not it will return ENOTCONN. This was a bug in the kernel which got fixed in later kernels. That is why retrying with a timer fixes the issue. [1]: https://github.com/docker/libnetwork/issues/1247
