openstack/kolla-ansible.git/doc/source/reference/compute, branch stable/2026.1

Tune libvirtd connection limits for OpenStack

2026-06-29T00:11:47+00:00

The libvirt daemon ships with max_workers=20 and max_client_requests=5. Those defaults suit a multi-tenant host serving many mutually distrustful clients, where the per-client request cap protects the daemon from any single client monopolising it. Under Kolla-Ansible, nova-compute is effectively the sole privileged client of libvirtd, so the cap of 5 concurrent requests per client becomes the binding constraint rather than a safety net. When several instances build at once -- as they do during the tempest run of the upgrade jobs -- nova-compute's concurrent libvirt RPCs (instance defineXML calls plus the resource-tracker periodic) exceed five. Further requests queue, the connection's keepalive responses are starved, and after keepalive_interval (5s) x keepalive_count (5) = 25s libvirtd closes the connection. nova then sees "Cannot recv data: Input/output error" mid-defineXML, the build is rescheduled, and once all hosts are exhausted the instance is left in ERROR. This presents as flaky upgrade-job failures. Example failure, on the voting kolla-ansible-debian-bookworm-upgrade job (stable/2025.2): https://zuul.opendev.org/t/openstack/build/73ff5a97567d4e05b1774170e0f4aada with primary/logs/kolla/libvirt/libvirtd.txt showing libvirt's own recommendation to tune this parameter: warning : Client hit max requests limit 5. This may result in keep-alive timeouts. Consider tuning the max_client_requests server parameter ... error : connection closed due to keepalive timeout Raise the per-client cap to 20 -- comfortably above the handful of concurrent builds plus periodics seen in practice -- and the worker pool to 50 so that lifting the per-client limit does not starve other connections such as live migration, health checks and periodic tasks. Both values are exposed as variables (libvirt_max_client_requests and libvirt_max_workers) so operators can tune them further. This is not a Kolla-specific workaround -- the stock libvirtd.conf comment warns that setting max_client_requests too low "may cause keepalive timeouts", and since 2022 libvirtd emits the runtime warning quoted above. As Daniel Berrange explained when he added that warning, the keepalive packets "are subject to the 'max_client_requests' limit just like any API calls", so a client that saturates the limit can have its connection dropped: https://lists.libvirt.org/archives/list/devel@lists.libvirt.org/message/5NIJPA7SJVY55VSK7RTEDEHKWOZYJKT6/ Red Hat documents the same tuning for libvirt hosts under load in its knowledge base, notably "Too many active clients are dropping the connection" at https://access.redhat.com/solutions/28146. Assisted-By: Claude Opus 4.8 (1M context, medium effort) Partial-Bug: 2158515 Change-Id: I131c3d4d57dc73ca4dd421cc8f28465248c9830e (cherry picked from commit 5acd2f91d22213ef04bd6988a2a0261982b0cf05) Signed-off-by: Michael Still

Drop zun and kuryr

2026-04-27T05:18:03+00:00

Zun is broken in 2026.1, it has been released broken and there are no reviews on the patch to fix it [1]. [1]: https://review.opendev.org/c/openstack/zun/+/982362 Depends-On: https://review.opendev.org/c/openstack/ansible-collection-kolla/+/986150 Change-Id: I8ced621754d03c44b7672dd94fc3d7d2173ac734 Signed-off-by: Michal Nasiadka

Merge "Fix: Update outdated documentation"

2026-04-16T14:54:58+00:00

Fix: Update outdated documentation

2026-04-12T15:31:35+00:00

Change-Id: I5dc53f74afd9a5b565201dc9d3039d82cb65dabc Signed-off-by: Piotr Milewski

Add additional SPICE configuration options

2026-04-02T20:05:13+00:00

Recent changes to OpenStack Compute have added a number of new configuration options for SPICE VDI consoles. Additionally, it is not always desirable to enable the HTML5 transcoding proxy for SPICE consoles in Horizon. This patch adds configuration to globals.yml for most of these new options. Specifically: * nova_spice_html5: whether to enable the HTML5 transcoding proxy or not. Defaults to the previous behaviour of enabling the proxy. Notably, nova_spice_require_secure is not exposed here as it implies that qemu is configured to support TLS, and that TLS certificates have been configured in the nova_libvirt container. These changes are large, and are included in a separate patch for clarity. Additionally, OpenStack Compute added these configuration options in 2023.1, and they are exposed as well: * nova_spice_image_compression: "auto_glz" * nova_spice_jpeg_compression: "auto" * nova_spice_zlib_compression: "auto" * nova_spice_playback_compression: true * nova_spice_streaming_mode: "filter" All configuration options and their various values are documented by OpenStack Compute in their documentation. Partial-Bug: #2131793 (spice-direct consoles) Change-Id: I07f6890f1c7c4e543667d3cbd7b3e82bd9ec83e3 Signed-off-by: Michael Still

Add support for libvirt swtpm (vTPM) configuration.

2025-12-15T09:27:24+00:00

Since both nova-compute and nova-libvirt Kolla images have swtpm packages installed [1], it is possible to configure vTPM for libvirt instances. This patch adds support for such configuration in kolla-ansible. [1] https://bugs.launchpad.net/kolla/+bug/2062572 Closes-Bug: #2106219 Change-Id: Ic7969b05bde258c38ee31fe2821aeb4e9c77a567 Signed-off-by: fprzewozn

Drop VMware support

2025-08-07T14:42:57+00:00

Change-Id: I20a669bf7796285df04723a9110f9c74788600e1 Signed-off-by: Michal Nasiadka

Fix docs rendering errors.

2025-06-03T15:54:01+00:00

I was reading https://docs.openstack.org's version of the kolla-ansible advanced configuration guide and noticed some RST rendering errors. This patch corrects those errors so that the page renders correctly. Change-Id: I330678d8971d286e67f115eace1cb606d30433b6

Merge "Revert "Deprecate Masakari""

2024-04-25T12:48:36+00:00

Revert "Deprecate Masakari"

2024-04-19T07:43:59+00:00

This reverts commit 9675347fecd2907e7f60e84e405abcedf426b229. Reason for revert: Masakari CI is working Change-Id: Ifb44a437b96c0c029210b1491ee6c6403ee9e6fb