From d27022fe5fc49292e49f45d98c1c9cf0b76f1454 Mon Sep 17 00:00:00 2001
From: fjetter <fjetter@users.noreply.github.com>
Date: Wed, 16 Apr 2025 11:42:36 +0200
Subject: [PATCH 1/3] Cache WorkerState.host

---
 distributed/scheduler.py | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/distributed/scheduler.py b/distributed/scheduler.py
index a026e897ed6..a743cada0e3 100644
--- a/distributed/scheduler.py
+++ b/distributed/scheduler.py
@@ -31,7 +31,7 @@
     Set,
 )
 from contextlib import suppress
-from functools import partial
+from functools import cached_property, partial
 from typing import TYPE_CHECKING, Any, ClassVar, Literal, NamedTuple, cast, overload
 
 import psutil
@@ -584,7 +584,7 @@ def has_what(self) -> Set[TaskState]:
         """
         return self._has_what.keys()
 
-    @property
+    @cached_property
     def host(self) -> str:
         return get_address_host(self.address)
 

From d084e58eefcd354f293eed83238f8aff194c3f5a Mon Sep 17 00:00:00 2001
From: fjetter <fjetter@users.noreply.github.com>
Date: Wed, 16 Apr 2025 12:58:10 +0200
Subject: [PATCH 2/3] as attribute

---
 distributed/scheduler.py | 9 ++++-----
 1 file changed, 4 insertions(+), 5 deletions(-)

diff --git a/distributed/scheduler.py b/distributed/scheduler.py
index a743cada0e3..b0922b5451e 100644
--- a/distributed/scheduler.py
+++ b/distributed/scheduler.py
@@ -31,7 +31,7 @@
     Set,
 )
 from contextlib import suppress
-from functools import cached_property, partial
+from functools import partial
 from typing import TYPE_CHECKING, Any, ClassVar, Literal, NamedTuple, cast, overload
 
 import psutil
@@ -513,6 +513,8 @@ class WorkerState:
     #: on the worker.
     needs_what: dict[TaskState, int]
 
+    host: str
+
     __slots__ = tuple(__annotations__)
 
     def __init__(
@@ -564,6 +566,7 @@ def __init__(
         self.needs_what = {}
         self._network_occ = 0
         self._occupancy_cache = None
+        self.host = get_address_host(self.address)
 
     def __hash__(self) -> int:
         return self._hash
@@ -584,10 +587,6 @@ def has_what(self) -> Set[TaskState]:
         """
         return self._has_what.keys()
 
-    @cached_property
-    def host(self) -> str:
-        return get_address_host(self.address)
-
     @property
     def memory(self) -> MemoryState:
         """Polished memory metrics for the worker.

From 53fad0169e25debe31d54dcfbb09957d55b8648f Mon Sep 17 00:00:00 2001
From: fjetter <fjetter@users.noreply.github.com>
Date: Wed, 16 Apr 2025 14:03:25 +0200
Subject: [PATCH 3/3] final hints

---
 distributed/scheduler.py | 16 +++++++++++++---
 1 file changed, 13 insertions(+), 3 deletions(-)

diff --git a/distributed/scheduler.py b/distributed/scheduler.py
index b0922b5451e..225a11ee86e 100644
--- a/distributed/scheduler.py
+++ b/distributed/scheduler.py
@@ -32,7 +32,16 @@
 )
 from contextlib import suppress
 from functools import partial
-from typing import TYPE_CHECKING, Any, ClassVar, Literal, NamedTuple, cast, overload
+from typing import (
+    TYPE_CHECKING,
+    Any,
+    ClassVar,
+    Final,
+    Literal,
+    NamedTuple,
+    cast,
+    overload,
+)
 
 import psutil
 import tornado.web
@@ -413,7 +422,7 @@ class WorkerState:
 
     #: This worker's unique key. This can be its connected address
     #: (such as ``"tcp://127.0.0.1:8891"``) or an alias (such as ``"alice"``).
-    address: str
+    address: Final[str]
 
     pid: int
     name: Hashable
@@ -513,7 +522,8 @@ class WorkerState:
     #: on the worker.
     needs_what: dict[TaskState, int]
 
-    host: str
+    #: The hostname / IP address identifying the machine this worker is on.
+    host: Final[str]
 
     __slots__ = tuple(__annotations__)