Bug 1717359
| Summary: | [OSP16] Configure log filter to capture interactions between libvirt and QEMU | |||
|---|---|---|---|---|
| Product: | Red Hat OpenStack | Reporter: | Kashyap Chamarthy <kchamart> | |
| Component: | openstack-tripleo-heat-templates | Assignee: | Martin Schuppert <mschuppe> | |
| Status: | CLOSED ERRATA | QA Contact: | Joe H. Rahme <jhakimra> | |
| Severity: | medium | Docs Contact: | ||
| Priority: | medium | |||
| Version: | 16.0 (Train) | CC: | gveitmic, mbooth, mburns, mschuppe | |
| Target Milestone: | Upstream M3 | Keywords: | Triaged, ZStream | |
| Target Release: | 16.0 (Train on RHEL 8.1) | |||
| Hardware: | Unspecified | |||
| OS: | Unspecified | |||
| Whiteboard: | ||||
| Fixed In Version: | puppet-nova-15.4.1-0.20191014175323.e6628d6.el8ost openstack-tripleo-heat-templates-11.3.1-0.20191022072831.698e7db.el8ost | Doc Type: | If docs needed, set a value | |
| Doc Text: | Story Points: | --- | ||
| Clone Of: | ||||
| : | 1745003 (view as bug list) | Environment: | ||
| Last Closed: | 2020-02-06 14:40:58 UTC | Type: | Bug | |
| Regression: | --- | Mount Type: | --- | |
| Documentation: | --- | CRM: | ||
| Verified Versions: | Category: | --- | ||
| oVirt Team: | --- | RHEL 7.3 requirements from Atomic Host: | ||
| Cloudforms Team: | --- | Target Upstream Version: | ||
| Embargoed: | ||||
| Bug Depends On: | ||||
| Bug Blocks: | 1745003, 1745005, 1745007 | |||
Since the problem described in this bug report should be resolved in a recent advisory, it has been closed with a resolution of ERRATA. For information on the advisory, and where to find the updated files, follow the link below. If the solution does not work for you, open a new bug report. https://access.redhat.com/errata/RHEA-2020:0283 |
What? ----- On all compute nodes, by default, enable the libvirt log filter ("1:qemu") to capture the QMP (QEMU Machine Protocol) traffic. This will show the QMP request and response flow between libvirt and QEMU. Why? ---- Often times, when debugging issues that involve interactions between Nova, libvirt and QEMU, we need to understand the precise requests that libvirt is sending to QEMU, and the corresponding responses from QEMU. Since we don't capture these interactions by default, we request them[*] _after_ a bug is reported, at which point it might not be possible to capture them for various reasons, or worse, the machine might no longer be available. Having this log filter enabled can be extremely useful in debugging a range of scenarios: live migration (with shared and non-shared storage), live snapshots, "volume migration", and anything that involves libvirt sending QMP commands to QEMU. Note that we're only selectively enabling a targetted log filter ("1:qemu"). It will slightly increase the log file size, but nothing crazy. This slight increase in log file size is acceptable, given the benefits. How? ---- When deploying compute nodes, make sure that TripleO sets the below two configuration attributes in `/etc/libvirt/libvirtd.conf`. The "1:qemu" log filter will capture the QMP traffic between libvirt and QEMU in the specified log file, `libvirtd.log`: ... log_filters="1:qemu" log_outputs="1:file:/var/log/libvirt/libvirtd.log" ... [*] https://kashyapc.fedorapeople.org/virt/openstack/request-nova-libvirt-qemu-debug-logs.txt