Remove functionality of batching submission in client.map

distributed/client.py

@@ -41,7 +41,7 @@
     from typing_extensions import TypeAlias
 
 from packaging.version import parse as parse_version
-from tlz import first, groupby, merge, partition_all, valmap
+from tlz import first, groupby, merge, valmap
 
 import dask
 from dask.base import collections_to_dsk, tokenize
@@ -2291,34 +2291,9 @@ def map(
             )
         total_length = sum(len(x) for x in iterables)
         if batch_size and batch_size > 1 and total_length > batch_size:
-            batches = list(
-                zip(*(partition_all(batch_size, iterable) for iterable in iterables))
-            )
-            keys: list[list[Any]] | list[Any]
-            if isinstance(key, list):
-                keys = [list(element) for element in partition_all(batch_size, key)]
-            else:
-                keys = [key for _ in range(len(batches))]
-            return sum(
-                (
-                    self.map(
-                        func,
-                        *batch,
-                        key=key,
-                        workers=workers,
-                        retries=retries,
-                        priority=priority,
-                        allow_other_workers=allow_other_workers,
-                        fifo_timeout=fifo_timeout,
-                        resources=resources,
-                        actor=actor,
-                        actors=actors,
-                        pure=pure,
-                        **kwargs,
-                    )
-                    for key, batch in zip(keys, batches)
-                ),
-                [],
+            warnings.warn(
+                'The argument "batch_size" is ignored and will be removed in a future version.',
+                DeprecationWarning,
             )
 
         key = key or funcname(func)

distributed/tests/test_client.py

@@ -243,16 +243,20 @@ async def test_map_retries(c, s, a, b):
 
 @gen_cluster(client=True)
 async def test_map_batch_size(c, s, a, b):
-    result = c.map(inc, range(100), batch_size=10)
+    with pytest.deprecated_call(match="batch_size"):
+        result = c.map(inc, range(100), batch_size=10)
     result = await c.gather(result)
     assert result == list(range(1, 101))
 
-    result = c.map(add, range(100), range(100), batch_size=10)
+    with pytest.deprecated_call(match="batch_size"):
+        result = c.map(add, range(100), range(100), batch_size=10)
     result = await c.gather(result)
     assert result == list(range(0, 200, 2))
 
     # mismatch shape
-    result = c.map(add, range(100, 200), range(10), batch_size=2)
+
+    with pytest.deprecated_call(match="batch_size"):
+        result = c.map(add, range(100, 200), range(10), batch_size=2)
     result = await c.gather(result)
     assert result == list(range(100, 120, 2))
 
@@ -261,12 +265,13 @@ async def test_map_batch_size(c, s, a, b):
 async def test_custom_key_with_batches(c, s, a, b):
     """Test of <https://github.com/dask/distributed/issues/4588>"""
 
-    futs = c.map(
-        lambda x: x**2,
-        range(10),
-        batch_size=5,
-        key=[str(x) for x in range(10)],
-    )
+    with pytest.deprecated_call(match="batch_size"):
+        futs = c.map(
+            lambda x: x**2,
+            range(10),
+            batch_size=5,
+            key=[str(x) for x in range(10)],
+        )
     assert len(futs) == 10
     await wait(futs)