Comment 0 for bug 1902276

Description
===========
This is current master branch (wallaby) of OpenStack.

We seen this regularly, but it's intermittent.

We are seeing nova instances that do not transition to ACTIVE inside five minutes. Investigating this led us to find that libvirtd seems to be going into a tight loop on an instance delete.

The 136MB log is here: https://storage.gra.cloud.ovh.net/v1/AUTH_dcaab5e32b234d56b626f72581e3644c/zuul_opendev_logs_c77/759973/3/check/octavia-v2-dsvm-scenario/c77fe63/controller/logs/libvirt/libvirtd_log.txt

The overall job logs are here:
https://zuul.opendev.org/t/openstack/build/c77fe63a94ef4298872ad5f40c5df7d4/logs

When running the Octavia scenario test suite, we occasionally see nova instances fail to become ACTIVE in a timely manner, causing timeouts and failures. In investigating this issue we found the libvirtd log was 136MB.

Most of the file is full of this repeating:
2020-10-28 23:45:06.330+0000: 20852: debug : qemuMonitorIO:767 : Error on monitor internal error: End of file from qemu monitor
2020-10-28 23:45:06.330+0000: 20852: debug : qemuMonitorIO:788 : Triggering EOF callback
2020-10-28 23:45:06.330+0000: 20852: debug : qemuProcessHandleMonitorEOF:301 : Received EOF on 0x7f6278014ca0 'instance-00000001'
2020-10-28 23:45:06.330+0000: 20852: debug : qemuProcessHandleMonitorEOF:305 : Domain is being destroyed, EOF is expected

Here is a snippet for the lead in to the repeated lines:
http://paste.openstack.org/show/799559/

It appears to be a tight loop, repeating many times per second.

Eventually it does stop and things seem to go back to normal in nova.

Here is the snippet of the end of the loop in the log:
http://paste.openstack.org/show/799560/