Hi folks, Lately I'm getting the question in the subject line more and more frequently and facing it myself, especially in the context of OpenStack.
The shift to OVN in OpenStack involves a totally different approach when it comes to tracing packet drops. Before OVN, there were a bunch of network namespaces and devices where you could hook a tcpdump on and inspect the traffic. People are used to those troubleshooting techniques and OVS was merely used for normal action switches. It's clear that there's tools and techniques to analyze this (trace tool, port mirroring, etc.), but often times requires quite high knowledge and understanding of the pipeline and OVS itself to effectively trace where a packet got dropped. Furthermore, there could be some scenarios where the packet can be silently dropped. I came across this patch [0] and presentation about it [1] which aims to tackle partly the problem described here (focusing in the DPDK datapath). The intent of this email is to gather some feedback as how to provide efficient tools and techniques to troubleshoot OVS/OVN issues and what do you think is immediately missing in this context. Thanks a lot! Daniel [0] https://patchwork.ozlabs.org/patch/918934/ which has been revived here: https://patchwork.ozlabs.org/patch/1048766/ [1] https://www.slideshare.net/LF_OpenvSwitch/lfovs17troubleshooting-the-data-plane-in-ovs-82280329 _______________________________________________ discuss mailing list disc...@openvswitch.org https://mail.openvswitch.org/mailman/listinfo/ovs-discuss
