FIX-#7355: Cpu count would be set incorrectly on a cluster

modin/config/envvars.py

@@ -332,6 +332,24 @@ class CpuCount(EnvironmentVariable, type=int):
 
     varname = "MODIN_CPUS"
 
+    @classmethod
+    def _put(cls, value: int) -> None:
+        """
+        Put specific value if CpuCount wasn't set by a user yet.
+
+        Parameters
+        ----------
+        value : int
+            Config value to set.
+
+        Notes
+        -----
+        This method is used to set CpuCount from cluster resources internally
+        and should not be called by a user.
+        """
+        if cls.get_value_source() == ValueSource.DEFAULT:
+            cls.put(value)
+
     @classmethod
     def _get_default(cls) -> int:
         """

modin/core/execution/dask/common/utils.py

@@ -74,3 +74,4 @@ def _disable_warnings():
 
     num_cpus = len(client.ncores())
     NPartitions._put(num_cpus)
+    CpuCount._put(num_cpus)

modin/core/execution/ray/common/utils.py

@@ -151,6 +151,7 @@ def initialize_ray(
 
     num_cpus = int(ray.cluster_resources()["CPU"])
     NPartitions._put(num_cpus)
+    CpuCount._put(num_cpus)
 
     # TODO(https://github.com/ray-project/ray/issues/28216): remove this
     # workaround once Ray gives a better way to suppress task errors.

modin/core/execution/unidist/common/utils.py

@@ -42,6 +42,7 @@ def initialize_unidist():
 
     num_cpus = sum(v["CPU"] for v in unidist.cluster_resources().values())
     modin_cfg.NPartitions._put(num_cpus)
+    modin_cfg.CpuCount._put(num_cpus)
 
 
 def deserialize(obj):  # pragma: no cover