to_dict changes

distributed/utils_test.py

@@ -40,6 +40,7 @@
     ssl = None  # type: ignore
 
 import pytest
+import yaml
 from tlz import assoc, memoize, merge
 from tornado import gen
 from tornado.ioloop import IOLoop
@@ -49,6 +50,7 @@
 from distributed.comm.tcp import TCP
 
 from . import system
+from . import versions as version_module
 from .client import Client, _global_clients, default_client
 from .comm import Comm
 from .compatibility import WINDOWS
@@ -990,26 +992,14 @@ async def coro():
                             # This stack indicates where the coro/test is suspended
                             task.print_stack(file=buffer)
 
-                            if client:
-                                assert c
+                            if cluster_dump_directory:
                                 try:
-                                    if cluster_dump_directory:
-                                        os.makedirs(
-                                            cluster_dump_directory, exist_ok=True
-                                        )
-                                        filename = os.path.join(
-                                            cluster_dump_directory, func.__name__
-                                        )
-                                        fut = c.dump_cluster_state(
-                                            filename,
-                                            # Test dumps should be small enough that
-                                            # there is no need for a compressed
-                                            # binary representation and readability
-                                            # is more important
-                                            format="yaml",
-                                        )
-                                        assert fut is not None
-                                        await fut
+                                    await dump_cluster_state(
+                                        s,
+                                        ws,
+                                        output_dir=cluster_dump_directory,
+                                        func_name=func.__name__,
+                                    )
                                 except Exception:
                                     print(
                                         f"Exception {sys.exc_info()} while trying to "
@@ -1096,6 +1086,46 @@ def get_unclosed():
     return _
 
 
+async def dump_cluster_state(
+    s: Scheduler, ws: list[ServerNode], output_dir: str, func_name: str
+) -> None:
+    """A variant of Client.dump_cluster_state, which does not expect on any of the below
+    to work:
+
+    - individual Workers
+    - Client->Scheduler comms
+    - Scheduler->Worker comms (unless using Nannies)
+    """
+    scheduler_info = s._to_dict()
+    versions_info = version_module.get_versions()
+
+    if not ws or isinstance(ws[0], Worker):
+        workers_info = {w.address: w._to_dict() for w in ws}
+    else:
+        # Variant of s.broadcast() that deals with unresponsive workers
+        async def safe_broadcast(addr: str) -> dict:
+            try:
+                return await s.broadcast(msg={"op": "dump_state"}, workers=[addr])
+            except Exception:
+                msg = f"Exception {sys.exc_info()} while trying to dump worker state"
+                return {addr: msg}
+
+        workers_info = merge(
+            await asyncio.gather(safe_broadcast(w.address) for w in ws)
+        )
+
+    state = {
+        "scheduler": scheduler_info,
+        "workers": workers_info,
+        "versions": versions_info,
+    }
+    os.makedirs(output_dir, exist_ok=True)
+    fname = os.path.join(output_dir, func_name) + ".yaml"
+    with open(fname, "w") as fh:
+        yaml.dump(state, fh)
+    print(f"Dumped cluster state to {fname}")
+
+
 def raises(func, exc=Exception):
     try:
         func()

distributed/worker.py

@@ -127,6 +127,8 @@
 
 SerializedTask = namedtuple("SerializedTask", ["function", "args", "kwargs", "task"])
 
+_taskstate_to_dict_guard = False
+
 
 class InvalidTransition(Exception):
     pass
@@ -226,7 +228,7 @@ def get_nbytes(self) -> int:
         nbytes = self.nbytes
         return nbytes if nbytes is not None else DEFAULT_DATA_SIZE
 
-    def _to_dict(self, *, exclude: Container[str] = ()) -> dict:
+    def _to_dict(self, *, exclude: Container[str] = ()) -> dict | str:
         """
         A very verbose dictionary representation for debugging purposes.
         Not type stable and not inteded for roundtrips.
@@ -241,10 +243,21 @@ def _to_dict(self, *, exclude: Container[str] = ()) -> dict:
         --------
         Client.dump_cluster_state
         """
-        return recursive_to_dict(
-            {k: v for k, v in self.__dict__.items() if k not in exclude},
-            exclude=exclude,
-        )
+        # When a task references another task, just print the task repr. All tasks
+        # should neatly appear under Worker.tasks. This also prevents a RecursionError
+        # during particularly heavy loads, which have been observed to happen whenever
+        # there's an acyclic dependency chain of ~200+ tasks.
+        global _taskstate_to_dict_guard
+        if _taskstate_to_dict_guard:
+            return repr(self)
+        _taskstate_to_dict_guard = True
+        try:
+            return recursive_to_dict(
+                {k: v for k, v in self.__dict__.items() if k not in exclude},
+                exclude=exclude,
+            )
+        finally:
+            _taskstate_to_dict_guard = False
 
     def is_protected(self) -> bool:
         return self.state in PROCESSING or any(