Open Stack

Hi Team,

Wanted to let you know why we are having consistent functional test 
failures in the gate.

This is being caused by Nova returning "No valid host" to heat:

2015-08-13 08:26:16.303 31543 INFO heat.engine.resource [-] CREATE: 
Server "kube_minion" [12ab45ef-0177-4118-9ba0-3fffbc3c1d1a] Stack 
"testbay-y366b2atg6mm-kube_minions-cdlfyvhaximr-0-dufsjliqfoet" 
[b40f0c9f-cb54-4d75-86c3-8a9f347a27a6]
2015-08-13 08:26:16.303 31543 ERROR heat.engine.resource Traceback (most 
recent call last):
2015-08-13 08:26:16.303 31543 ERROR heat.engine.resource File 
"/opt/stack/new/heat/heat/engine/resource.py", line 625, in _action_recorder
2015-08-13 08:26:16.303 31543 ERROR heat.engine.resource     yield
2015-08-13 08:26:16.303 31543 ERROR heat.engine.resource File 
"/opt/stack/new/heat/heat/engine/resource.py", line 696, in _do_action
2015-08-13 08:26:16.303 31543 ERROR heat.engine.resource     yield 
self.action_handler_task(action, args=handler_args)
2015-08-13 08:26:16.303 31543 ERROR heat.engine.resource File 
"/opt/stack/new/heat/heat/engine/scheduler.py", line 320, in wrapper
2015-08-13 08:26:16.303 31543 ERROR heat.engine.resource     step = 
next(subtask)
2015-08-13 08:26:16.303 31543 ERROR heat.engine.resource File 
"/opt/stack/new/heat/heat/engine/resource.py", line 670, in 
action_handler_task
2015-08-13 08:26:16.303 31543 ERROR heat.engine.resource     while not 
check(handler_data):
2015-08-13 08:26:16.303 31543 ERROR heat.engine.resource File 
"/opt/stack/new/heat/heat/engine/resources/openstack/nova/server.py", 
line 759, in check_create_complete
2015-08-13 08:26:16.303 31543 ERROR heat.engine.resource     return 
self.client_plugin()._check_active(server_id)
2015-08-13 08:26:16.303 31543 ERROR heat.engine.resource File 
"/opt/stack/new/heat/heat/engine/clients/os/nova.py", line 232, in 
_check_active
2015-08-13 08:26:16.303 31543 ERROR heat.engine.resource     'code': 
fault.get('code', _('Unknown'))
2015-08-13 08:26:16.303 31543 ERROR heat.engine.resource 
ResourceInError: Went to status ERROR due to "Message: No valid host was 
found. There are not enough hosts available., Code: 500"

And this in turn is being caused by the compute instance running out of 
disk space:

2015-08-13 08:26:15.216 DEBUG nova.filters 
[req-e5bb52cb-387e-4638-911e-8c72aa1b6400 admin admin] Starting with 1 
host(s) get_filtered_objects /opt/stack/new/nova/nova/filters.py:70
2015-08-13 08:26:15.217 DEBUG nova.filters 
[req-e5bb52cb-387e-4638-911e-8c72aa1b6400 admin admin] Filter 
RetryFilter returned 1 host(s) get_filtered_objects 
/opt/stack/new/nova/nova/filters.py:84
2015-08-13 08:26:15.217 DEBUG nova.filters 
[req-e5bb52cb-387e-4638-911e-8c72aa1b6400 admin admin] Filter 
AvailabilityZoneFilter returned 1 host(s) get_filtered_objects 
/opt/stack/new/nova/nova/filters.py:84
2015-08-13 08:26:15.217 DEBUG nova.filters 
[req-e5bb52cb-387e-4638-911e-8c72aa1b6400 admin admin] Filter RamFilter 
returned 1 host(s) get_filtered_objects 
/opt/stack/new/nova/nova/filters.py:84
2015-08-13 08:26:15.218 DEBUG nova.scheduler.filters.disk_filter 
[req-e5bb52cb-387e-4638-911e-8c72aa1b6400 admin admin] 
(devstack-trusty-rax-dfw-4299602, devstack-trusty-rax-dfw-4299602) 
ram:5172 disk:17408 io_ops:0 instances:1 does not have 20480 MB usable 
disk, it only has 17408.0 MB usable disk. host_passes 
/opt/stack/new/nova/nova/scheduler/filters/disk_filter.py:60
2015-08-13 08:26:15.218 INFO nova.filters 
[req-e5bb52cb-387e-4638-911e-8c72aa1b6400 admin admin] Filter DiskFilter 
returned 0 hosts

For now a recheck seems to work about 1 in 2, so we can still land patches.

The fix for this could be to clean up our Magnum devstack install more 
aggressively, which might be as simple as cleaning up the images we use, 
or get infra to provide our tests with a larger disk size. I will 
probably test out a patch today which cleans up the images we use in 
devstack to see if that helps.

If anyone can help progress this let me know.

Cheers,
Tom