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#openstack-nova - 2026-01-29
10:56:04 opendevreview Balazs Gibizer proposed openstack/nova master: Use an executor to delay STOPPED events https://review.opendev.org/c/openstack/nova/+/974445
10:56:04 opendevreview Balazs Gibizer proposed openstack/nova master: Enable mypy on nova/utils.py https://review.opendev.org/c/openstack/nova/+/969936
10:56:05 opendevreview Balazs Gibizer proposed openstack/nova master: Run nova-compute in native threading mode https://review.opendev.org/c/openstack/nova/+/965467
10:56:05 opendevreview Balazs Gibizer proposed openstack/nova master: Cleanup libvirt driver at service stop https://review.opendev.org/c/openstack/nova/+/975128
10:56:06 opendevreview Balazs Gibizer proposed openstack/nova master: DNM:Test with oslo.vmware + compute eventlet removal patches https://review.opendev.org/c/openstack/nova/+/973468
10:57:13 opendevreview Balazs Gibizer proposed openstack/nova master: Enable mypy on nova/utils.py https://review.opendev.org/c/openstack/nova/+/969936
10:57:30 opendevreview Balazs Gibizer proposed openstack/nova master: Use an executor to delay STOPPED events https://review.opendev.org/c/openstack/nova/+/974445
10:57:31 opendevreview Balazs Gibizer proposed openstack/nova master: Run nova-compute in native threading mode https://review.opendev.org/c/openstack/nova/+/965467
10:57:31 opendevreview Balazs Gibizer proposed openstack/nova master: Cleanup libvirt driver at service stop https://review.opendev.org/c/openstack/nova/+/975128
10:57:32 opendevreview Balazs Gibizer proposed openstack/nova master: DNM:Test with oslo.vmware + compute eventlet removal patches https://review.opendev.org/c/openstack/nova/+/973468
13:43:51 gibi fwiesel, sean-k-mooney : I see the issue behind the stack trace in the oslo.vmware native threaded run. This is probably a bug with the libvirt driver too. I will do the needful
14:07:11 sean-k-mooney gibi: ack
14:07:13 sean-k-mooney what was it
14:27:26 opendevreview Sylvain Bauza proposed openstack/nova stable/2025.2: Reproduce bug/2130881 https://review.opendev.org/c/openstack/nova/+/975162
14:27:27 opendevreview Sylvain Bauza proposed openstack/nova stable/2025.2: Init virt driver before use https://review.opendev.org/c/openstack/nova/+/975163
14:29:20 opendevreview Sylvain Bauza proposed openstack/nova stable/2025.1: Reproduce bug/2130881 https://review.opendev.org/c/openstack/nova/+/975164
14:29:21 opendevreview Sylvain Bauza proposed openstack/nova stable/2025.1: Init virt driver before use https://review.opendev.org/c/openstack/nova/+/975165
14:32:51 gibi sean-k-mooney: https://github.com/openstack/nova/blob/59a7093915298973c72b6d1749a6acd27e0045a9/nova/utils.py#L605 this should be conditional as not all executors has a name
14:33:27 gibi yet another refactoring (for the future) to ensure all our executors are named and created in the same way
14:33:30 opendevreview Sylvain Bauza proposed openstack/nova stable/2024.2: Reproduce bug/2130881 https://review.opendev.org/c/openstack/nova/+/975166
14:33:31 opendevreview Sylvain Bauza proposed openstack/nova stable/2024.2: Init virt driver before use https://review.opendev.org/c/openstack/nova/+/975167
14:33:41 sean-k-mooney yep i was just going to say
14:33:54 sean-k-mooney that or well we shoudl jsut not depend on it for the warning
15:24:02 opendevreview sean mooney proposed openstack/nova master: Add regression test to repoduce bug 2139351 https://review.opendev.org/c/openstack/nova/+/975171
15:39:23 opendevreview Balazs Gibizer proposed openstack/nova master: Run nova-compute in native threading mode https://review.opendev.org/c/openstack/nova/+/965467
15:39:24 opendevreview Balazs Gibizer proposed openstack/nova master: Fix full executor warning on noname executor https://review.opendev.org/c/openstack/nova/+/975172
15:39:24 opendevreview Balazs Gibizer proposed openstack/nova master: DNM:Test with oslo.vmware + compute eventlet removal patches https://review.opendev.org/c/openstack/nova/+/973468
15:44:34 gibi sean-k-mooney: btw there are bigger issues in the vmware logs than that stack trace.
15:44:40 gibi [10197.783268] env[89459]: WARNING nova.utils [None req-08c5913a-0cad-45f4-991c-76f091773eb3 tempest-ServersTestJSON-388458959 tempest-ServersTestJSON-388458959-project-member] The MainProcess.default pool does not have free threads so the task <function ComputeManager.build_and_run_instance.<locals>._locked_do_build_and_run_instance at 0x7647d040cee0> will be queued. If this happens repeatedly then
15:44:46 gibi the size of the pool is too small for the load or there are stuck threads filling the pool.
15:45:11 gibi this is the reason why VM builds are failing. Something is using up our thread pool
15:45:30 sean-k-mooney gibi: i notice a few other tracebaces ya but i was nto sure wht are "expected error" vs related to event let liek the "expected" os-brick errors
15:46:31 sean-k-mooney so to get the message that means somting is callign spawn right?
15:46:51 sean-k-mooney as in it can only get to that executor by going thorugh the nova.utils metods
15:47:24 sean-k-mooney which means it has to be in hte nova side fo the vmware driver rather then oslo.vmware
15:47:48 gibi yepp _locked_do_build_and_run_instance calling the spawn. That is normal, but somewho we run out of workers in the pool so somethign is hanging
15:48:38 gibi https://github.com/openstack/nova/blob/59a7093915298973c72b6d1749a6acd27e0045a9/nova/compute/manager.py#L2455
15:49:51 gibi we need a run with thread_pool_statistic_period=0 to get all the places that puts work into that pool to see when we start running out of workers
15:50:39 gibi I can look at differently to see if all VM boots are failing or not
15:51:13 gibi to try to get what was the first failed boot on the compute and see previous successful boot (if any) doing something that does not return a worker
15:53:48 sean-k-mooney sounds like a resonable plan of attack
15:54:11 sean-k-mooney you could jsut add a dnm to make 0 the default for testing
16:04:38 opendevreview Merged openstack/os-vif master: Add TAP device pre-creation support for OVS/OVN https://review.opendev.org/c/openstack/os-vif/+/971231
18:33:16 opendevreview Merged openstack/os-vif master: Fixed bridge name when per_port_bridge is used https://review.opendev.org/c/openstack/os-vif/+/966410
22:36:35 gmaan sean-k-mooney: thanks for reply on Fair lock comments, I am good on that except one new comment https://review.opendev.org/c/openstack/nova/+/973438/comment/ff4bb8ea_53533e58/
22:37:21 gmaan sean-k-mooney: if that comment make sense then i am ok to fix that in follow up because current change is in mergable state. let me know.
#openstack-nova - 2026-01-30
03:51:34 opendevreview Ghanshyam proposed openstack/nova master: Add a new field 'topic_alt' in service: object, DB, notification payload https://review.opendev.org/c/openstack/nova/+/975240
03:54:35 opendevreview Ghanshyam proposed openstack/nova master: Add a new field 'topic_alt' in service: object, DB, notification payload https://review.opendev.org/c/openstack/nova/+/975240
04:27:08 opendevreview Ghanshyam proposed openstack/nova master: Add 2nd RPC server for compute service https://review.opendev.org/c/openstack/nova/+/975242
04:28:21 opendevreview Ghanshyam proposed openstack/nova master: Add 2nd RPC server for compute service https://review.opendev.org/c/openstack/nova/+/975242
04:41:10 gmaan gibi: bauzas: these two change (adding 2nd RPC server) for graceful shutdown series are ready for review: https://review.opendev.org/c/openstack/nova/+/975240 https://review.opendev.org/c/openstack/nova/+/975242
06:40:12 opendevreview huanhongda proposed openstack/nova master: Live migration with iothreads https://review.opendev.org/c/openstack/nova/+/975000
06:52:05 opendevreview huanhongda proposed openstack/nova master: Live migration with iothreads https://review.opendev.org/c/openstack/nova/+/975000
08:43:32 bauzas gmaan: saw those, will try to do review them today but my day is already packed with review needs
09:39:37 opendevreview huanhongda proposed openstack/nova master: Live migration with iothreads https://review.opendev.org/c/openstack/nova/+/975000
10:36:11 gibi gmaan: did my first review round on the second RPC patches and left comments
15:02:52 gibi sean-k-mooney: heh I think I see how the oslo.vmware job could run out of threads in the default pool. If there are at least two differnt type of task is using the default pool during a single VM boot like buil_and_run_instance and then later that task spawns _allocate_network_async then if the pool size is e.g. 5 and I send in 10 parallel VM boot requests. Then the first 5 VM boot fills the pool and
15:02:58 gibi then none of them can move forward as the _allocate_network_async task for each of them is also queued up waiting for executor.
15:04:02 sean-k-mooney ah i see
15:04:56 sean-k-mooney i guess im not sure why buil_and_run_instance or _allocate_network_async woudl be dispatced to the defautl thread pool in the first place
15:05:17 sean-k-mooney the should both be on the rpc trhead pool.
15:06:11 sean-k-mooney if we had to use utils.spawn inside if for some async work i can see it having contention but it shoudl not deadlock
15:06:35 sean-k-mooney oh
15:06:48 sean-k-mooney no it could
15:07:04 gibi for some historical reasons build_and_run is moved to the default pool from the RPC pool. And then that task utils.spawns the network task
15:07:12 sean-k-mooney i guess a task that is on a executor shoudl never dispatch an other task to the same executor
15:07:21 sean-k-mooney if it does it could alwasy starve
15:07:26 gibi yeah
15:07:57 sean-k-mooney ok wll i think the network task shoudl jsut move to the io thread pool
15:08:03 sean-k-mooney at least for the short term
15:08:08 sean-k-mooney rather the the default
15:08:44 gibi yeah. Long term I need to think how can we prevent a new task being introduced and spawned to the same pool as the parent task
15:09:30 sean-k-mooney so we are not seeing this in the libvirt driver because this behvior is vmware dirver specific?
15:10:08 gibi nope I see it in the libvirt dirver too
15:10:10 gibi now that I know what to look for
15:10:25 gibi both task are from the compute manager so the problem is virt driver agnostic
15:11:03 gibi it seems tempest in our CI never tried to spawn more than 2-3 VMs in parallel but oslo.vmaware CI does so
15:11:08 sean-k-mooney ack in that case for now we coudl use the io thread pool for all network or file operations and the default for normal function calls?
15:11:35 gibi I will take a closer look at all utils.spawn call to see how much contention we have
15:11:49 gibi but yes in general we need to separate out these tasks to different pools
15:12:53 sean-k-mooney not a now descison but we might actully want a "packaged task" construct in the future where we can package up a closure of the task to be executeded (with cansletion if need) and metadata to tack/prevent this
15:13:36 sean-k-mooney i.e. so we know what executor we are on and on what executor we can spawn the task
15:14:16 gibi yeah a generic solution probably needs some tracking metadata
15:14:17 sean-k-mooney for now we could add a simple execotre fild to the nova context object which is None by defualt but set to a link to the execotre by spawn
15:14:39 sean-k-mooney then spawn could check if we are ever tying to spawn a task on teh same executor and raise
15:14:49 gibi yeah context is not a bad idea
15:14:50 gibi thanks
15:15:29 sean-k-mooney the reason i said we might need a packaged task in the future is i dont know if we have the context as an arguemt every where we are usign spawn but we might
15:16:12 sean-k-mooney i.e. if we are currently spawning a fucntion that does not take the context as its first argument then we woudl either need to add it or find a diffent solution
15:16:18 sean-k-mooney but thats what i woudl try first
15:16:46 gibi context should be in a thread local store, I can check if we can grab it from there
15:18:00 sean-k-mooney oh you might be right i vagely remoemebr ther ebeing a psudo signelton function to get it at module scope
15:18:13 gibi btw, this logic to move the build_and_run_instance from the RPC to the default pool might not be a valid strategy any more for native threading. In eventlet we had 60 RPC worker but potentially unlimited worker in the default pool. So the default pool was bigger. But in native threading the default pool is smaller than the RPC worker pool.
15:20:02 gibi (by default)
15:20:09 sean-k-mooney ya im not sure it really requried (or why it was done)
15:20:29 sean-k-mooney just runign it on the rpc thread i think should be ok
15:21:29 sean-k-mooney even if it was the same size i dont think we shoudl design the system so that with the incorrect config value you can deadlock
15:21:58 sean-k-mooney so threading may be highlighting the problem but i would say it was still a bug even with eventlet
15:23:03 gibi I think it originally was done to avoid build requests to hold up the RPC pool and prevent other lifecycle operations to progress in the meantime
15:23:58 gibi https://github.com/openstack/nova/blob/59a7093915298973c72b6d1749a6acd27e0045a9/nova/compute/manager.py#L2452-L2460

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