[Nebius] Support spot instances and B200 (#2965)

* [Nebius] Support spot instances and B200 #2954

* [Nebius] Ensure the SDK supports spot instances

Author: peterschmidt85

pyproject.toml

@@ -176,7 +176,7 @@ oci = [
     "dstack[server]",
 ]
 nebius = [
-    "nebius>=0.2.19,<0.3; python_version >= '3.10'",
+    "nebius>=0.2.40,<0.3; python_version >= '3.10'",
     "dstack[server]",
 ]
 all = [

src/dstack/_internal/core/backends/nebius/compute.py

@@ -74,6 +74,7 @@
 SUPPORTED_PLATFORMS = [
     "gpu-h100-sxm",
     "gpu-h200-sxm",
+    "gpu-b200-sxm",
     "gpu-l40s-a",
     "gpu-l40s-d",
     "cpu-d3",
@@ -150,12 +151,16 @@ def create_instance(
             )
             if backend_data.cluster is not None:
                 cluster_id = backend_data.cluster.id
+
+        gpus = instance_offer.instance.resources.gpus
         create_disk_op = resources.create_disk(
             sdk=self._sdk,
             name=instance_name,
             project_id=self._region_to_project_id[instance_offer.region],
             size_mib=instance_offer.instance.resources.disk.size_mib,
-            image_family="ubuntu22.04-cuda12",
+            image_family="ubuntu24.04-cuda12"
+            if gpus and gpus[0].name == "B200"
+            else "ubuntu22.04-cuda12",
         )
         create_instance_op = None
         try:
@@ -180,6 +185,7 @@ def create_instance(
                 cluster_id=cluster_id,
                 disk_id=create_disk_op.resource_id,
                 subnet_id=self._get_subnet_id(instance_offer.region),
+                preemptible=instance_offer.instance.resources.spot,
             )
             _wait_for_instance(self._sdk, create_instance_op)
         except BaseException:
@@ -367,4 +373,4 @@ def _wait_for_instance(sdk: SDK, op: SDKOperation[Operation]) -> None:
 
 def _supported_instances(offer: InstanceOffer) -> bool:
     platform, _ = offer.instance.name.split()
-    return platform in SUPPORTED_PLATFORMS and not offer.instance.resources.spot
+    return platform in SUPPORTED_PLATFORMS

src/dstack/_internal/core/backends/nebius/fabrics.py

@@ -21,6 +21,7 @@ class InfinibandFabric:
     InfinibandFabric("fabric-6", "gpu-h100-sxm", "eu-north1"),
     InfinibandFabric("fabric-7", "gpu-h200-sxm", "eu-north1"),
     InfinibandFabric("us-central1-a", "gpu-h200-sxm", "us-central1"),
+    InfinibandFabric("us-central1-b", "gpu-b200-sxm", "us-central1"),
 ]
 
 

src/dstack/_internal/core/backends/nebius/resources.py

@@ -28,10 +28,12 @@
     GpuClusterSpec,
     Instance,
     InstanceGpuClusterSpec,
+    InstanceRecoveryPolicy,
     InstanceServiceClient,
     InstanceSpec,
     IPAddress,
     NetworkInterfaceSpec,
+    PreemptibleSpec,
     PublicIPAddress,
     ResourcesSpec,
     SourceImageFamily,
@@ -283,6 +285,7 @@ def create_instance(
     cluster_id: Optional[str],
     disk_id: str,
     subnet_id: str,
+    preemptible: bool,
 ) -> SDKOperation[Operation]:
     client = InstanceServiceClient(sdk)
     request = CreateInstanceRequest(
@@ -306,6 +309,12 @@ def create_instance(
                     public_ip_address=PublicIPAddress(static=True),
                 )
             ],
+            preemptible=PreemptibleSpec(
+                priority=1, on_preemption=PreemptibleSpec.PreemptionPolicy.STOP
+            )
+            if preemptible
+            else None,
+            recovery_policy=InstanceRecoveryPolicy.FAIL if preemptible else None,
         ),
     )
     with wrap_capacity_errors():