ensure thread is at least 1

Author: sanderegg

services/autoscaling/src/simcore_service_autoscaling/modules/dask.py

@@ -347,7 +347,7 @@ async def try_retire_nodes(
 def add_instance_generic_resources(
     settings: DaskMonitoringSettings, instance: EC2InstanceData
 ) -> None:
-    instance_threads = round(instance.resources.cpus)
+    instance_threads = min(1, round(instance.resources.cpus))
     if settings.DASK_NTHREADS > 0:
         # this overrides everything
         instance_threads = settings.DASK_NTHREADS
@@ -365,7 +365,7 @@ def add_instance_generic_resources(
 def add_instance_type_generic_resource(
     settings: DaskMonitoringSettings, instance_type: EC2InstanceType
 ) -> None:
-    instance_threads = round(instance_type.resources.cpus)
+    instance_threads = min(1, round(instance_type.resources.cpus))
     if settings.DASK_NTHREADS > 0:
         # this overrides everything
         instance_threads = settings.DASK_NTHREADS