Upgrade default CPU instance types (skypilot-org#1613)

* Upgrade default instance types

* Fix optimizer test

Author: WoosukKwon

sky/clouds/aws.py

@@ -275,7 +275,8 @@ def is_same_cloud(self, other: clouds.Cloud):
 
     @classmethod
     def get_default_instance_type(cls) -> str:
-        # 8 vCpus, 32 GB RAM. 3rd generation Intel Xeon. General Purpose.
+        # General-purpose instance with 8 vCPUs and 32 GB RAM.
+        # Intel Ice Lake 8375C
         return 'm6i.2xlarge'
 
     # TODO: factor the following three methods, as they are the same logic

sky/clouds/azure.py

@@ -95,8 +95,9 @@ def is_same_cloud(self, other):
 
     @classmethod
     def get_default_instance_type(cls) -> str:
-        # 8 vCpus, 32 GB RAM.  Prev-gen (as of 2021) general purpose.
-        return 'Standard_D8_v4'
+        # General-purpose instance with 8 vCPUs and 32 GB RAM.
+        # Intel Ice Lake 8370C
+        return 'Standard_D8_v5'
 
     def _get_image_config(self, gen_version, instance_type):
         # az vm image list \

sky/clouds/gcp.py

@@ -280,8 +280,9 @@ def get_image_size(self, image_id: str, region: Optional[str]) -> float:
 
     @classmethod
     def get_default_instance_type(cls) -> str:
-        # 8 vCpus, 52 GB RAM.  First-gen general purpose.
-        return 'n1-highmem-8'
+        # General-purpose instance with 8 vCPUs and 32 GB RAM.
+        # Intel Ice Lake 8373C or Cascade Lake 6268CL
+        return 'n2-standard-8'
 
     @classmethod
     def _get_default_region(cls) -> clouds.Region:

tests/test_optimizer_random_dag.py

@@ -12,7 +12,7 @@
     'Azure': sky.Azure(),
 }
 ALL_INSTANCE_TYPES = sum(sky.list_accelerators(gpus_only=True).values(), [])
-GCP_DEFAULT_INSTANCE_TYPE = sky.GCP.get_default_instance_type()
+GCP_HOST_VM = 'n1-highmem-8'
 
 DUMMY_NODES = [
     sky.optimizer._DUMMY_SOURCE_NAME,
@@ -67,7 +67,7 @@ def generate_random_dag(
             for candidate in candidate_instance_types:
                 instance_type = candidate.instance_type
                 if pd.isna(instance_type):
-                    instance_type = GCP_DEFAULT_INSTANCE_TYPE
+                    instance_type = GCP_HOST_VM
                 resources = sky.Resources(
                     cloud=CLOUDS[candidate.cloud],
                     instance_type=instance_type,