[Core] Added support for submission-time task names. (#10449)

* Added support for submission-time task names.

* Suggestions from code review: add missing consts

Co-authored-by: SangBin Cho <rkooo567@gmail.com>

* Add num_returns arg to actor method options docstring example.

* Add process name line and proctitle assertion to submission-time task name section of advanced docs.

* Add submission-time task name --> proctitle test for Python worker.

* Added Python actor options tests for num_returns and name.

* Added Java test for submission-time task names.

* Add dashboard image to task name docs section.

* Move to fstrings.

Co-authored-by: SangBin Cho <rkooo567@gmail.com>

python/ray/tests/test_advanced_3.py

@@ -35,7 +35,7 @@ def attempt_to_load_balance(remote_function,
             [remote_function.remote(*args) for _ in range(total_tasks)])
         names = set(locations)
         counts = [locations.count(name) for name in names]
-        logger.info("Counts are {}.".format(counts))
+        logger.info(f"Counts are {counts}.")
         if (len(names) == num_nodes
                 and all(count >= minimum_count for count in counts)):
             break
@@ -346,6 +346,28 @@ def test_ray_setproctitle(ray_start_2_cpus):
     ray.get(unique_1.remote())
 
 
+def test_ray_task_name_setproctitle(ray_start_2_cpus):
+    method_task_name = "foo"
+
+    @ray.remote
+    class UniqueName:
+        def __init__(self):
+            assert setproctitle.getproctitle() == "ray::UniqueName.__init__()"
+
+        def f(self):
+            assert setproctitle.getproctitle() == f"ray::{method_task_name}"
+
+    task_name = "bar"
+
+    @ray.remote
+    def unique_1():
+        assert task_name in setproctitle.getproctitle()
+
+    actor = UniqueName.remote()
+    ray.get(actor.f.options(name=method_task_name).remote())
+    ray.get(unique_1.options(name=task_name).remote())
+
+
 @pytest.mark.skipif(
     os.getenv("TRAVIS") is None,
     reason="This test should only be run on Travis.")
@@ -508,7 +530,7 @@ def test_invalid_unicode_in_worker_log(shutdown_only):
 
     # Wait till first worker log file is created.
     while True:
-        log_file_paths = glob.glob("{}/worker*.out".format(logs_dir))
+        log_file_paths = glob.glob(f"{logs_dir}/worker*.out")
         if len(log_file_paths) == 0:
             time.sleep(0.2)
         else:
@@ -546,13 +568,13 @@ def test_move_log_files_to_old(shutdown_only):
 
     # Make sure no log files are in the "old" directory before the actors
     # are killed.
-    assert len(glob.glob("{}/old/worker*.out".format(logs_dir))) == 0
+    assert len(glob.glob(f"{logs_dir}/old/worker*.out")) == 0
 
     # Now kill the actors so the files get moved to logs/old/.
     [a.__ray_terminate__.remote() for a in actors]
 
     while True:
-        log_file_paths = glob.glob("{}/old/worker*.out".format(logs_dir))
+        log_file_paths = glob.glob(f"{logs_dir}/old/worker*.out")
         if len(log_file_paths) > 0:
             with open(log_file_paths[0], "r") as f:
                 assert "function f finished\n" in f.readlines()
@@ -641,7 +663,7 @@ Blacklisted:     No
     """
     constraints_dict = resource_spec._constraints_from_gpu_info(info_string)
     expected_dict = {
-        "{}V100".format(ray_constants.RESOURCE_CONSTRAINT_PREFIX): 1
+        f"{ray_constants.RESOURCE_CONSTRAINT_PREFIX}V100": 1,
     }
     assert constraints_dict == expected_dict
 
@@ -658,7 +680,7 @@ Blacklisted:     No
     """
     constraints_dict = resource_spec._constraints_from_gpu_info(info_string)
     expected_dict = {
-        "{}T4".format(ray_constants.RESOURCE_CONSTRAINT_PREFIX): 1
+        f"{ray_constants.RESOURCE_CONSTRAINT_PREFIX}T4": 1,
     }
     assert constraints_dict == expected_dict