diff --git a/nova/conductor/manager.py b/nova/conductor/manager.py
index fb1530a39d62..c9067a971312 100644
--- a/nova/conductor/manager.py
+++ b/nova/conductor/manager.py
@@ -19,9 +19,9 @@ import contextlib
 import copy
 import functools
 import sys
+import threading
 import typing as ty
 
-import futurist
 from keystoneauth1 import exceptions as ks_exc
 from oslo_config import cfg
 from oslo_db import exception as db_exc
@@ -2062,7 +2062,7 @@ class ComputeTaskManager:
                           the host list
         :param image_id: The IDs of the image to cache
         """
-
+        local_lock = threading.Lock()
         # TODO(mriedem): Consider including the list of images in the
         # notification payload.
         compute_utils.notify_about_aggregate_action(
@@ -2072,7 +2072,7 @@ class ComputeTaskManager:
 
         clock = timeutils.StopWatch()
         threads = CONF.image_cache.precache_concurrency
-        fetch_executor = futurist.GreenThreadPoolExecutor(max_workers=threads)
+        fetch_executor = utils.create_executor(threads)
 
         hosts_by_cell = {}
         cells_by_uuid = {}
@@ -2099,24 +2099,24 @@ class ComputeTaskManager:
         }
 
         def host_completed(context, host, result):
-            for image_id, status in result.items():
-                cached, existing, error, unsupported = stats[image_id]
-                if status == 'error':
-                    failed_images[image_id] += 1
-                    error += 1
-                elif status == 'cached':
-                    cached += 1
-                elif status == 'existing':
-                    existing += 1
-                elif status == 'unsupported':
-                    unsupported += 1
-                stats[image_id] = (cached, existing, error, unsupported)
+            with local_lock:
+                for image_id, status in result.items():
+                    cached, existing, error, unsupported = stats[image_id]
+                    if status == 'error':
+                        failed_images[image_id] += 1
+                        error += 1
+                    elif status == 'cached':
+                        cached += 1
+                    elif status == 'existing':
+                        existing += 1
+                    elif status == 'unsupported':
+                        unsupported += 1
+                    stats[image_id] = (cached, existing, error, unsupported)
 
             host_stats['completed'] += 1
-            compute_utils.notify_about_aggregate_cache(context, aggregate,
-                                                       host, result,
-                                                       host_stats['completed'],
-                                                       host_stats['total'])
+            compute_utils.notify_about_aggregate_cache(
+                context, aggregate, host, result,
+                host_stats['completed'], host_stats['total'])
 
         def wrap_cache_images(ctxt, host, image_ids):
             result = self.compute_rpcapi.cache_images(
diff --git a/nova/utils.py b/nova/utils.py
index 38fdd79fefd8..db00c515bdd5 100644
--- a/nova/utils.py
+++ b/nova/utils.py
@@ -104,19 +104,23 @@ def destroy_default_executor():
     DEFAULT_EXECUTOR = None
 
 
+def create_executor(max_workers):
+    if concurrency_mode_threading():
+        executor = futurist.ThreadPoolExecutor(max_workers)
+    else:
+        executor = futurist.GreenThreadPoolExecutor(max_workers)
+    return executor
+
+
 def _get_default_executor():
     global DEFAULT_EXECUTOR
 
     if not DEFAULT_EXECUTOR:
-        if concurrency_mode_threading():
-            DEFAULT_EXECUTOR = futurist.ThreadPoolExecutor(
-                CONF.default_thread_pool_size
+        max_workers = (
+            CONF.default_thread_pool_size if concurrency_mode_threading()
+            else CONF.default_green_pool_size
             )
-        else:
-            DEFAULT_EXECUTOR = futurist.GreenThreadPoolExecutor(
-                CONF.default_green_pool_size
-            )
-
+        DEFAULT_EXECUTOR = create_executor(max_workers)
         pname = multiprocessing.current_process().name
         executor_name = f"{pname}.default"
         DEFAULT_EXECUTOR.name = executor_name
@@ -1183,11 +1187,11 @@ def get_scatter_gather_executor():
     global SCATTER_GATHER_EXECUTOR
 
     if not SCATTER_GATHER_EXECUTOR:
-        if concurrency_mode_threading():
-            SCATTER_GATHER_EXECUTOR = futurist.ThreadPoolExecutor(
-                CONF.cell_worker_thread_pool_size)
-        else:
-            SCATTER_GATHER_EXECUTOR = futurist.GreenThreadPoolExecutor()
+        max_workers = (
+            CONF.cell_worker_thread_pool_size
+            if concurrency_mode_threading() else 1000
+            )
+        SCATTER_GATHER_EXECUTOR = create_executor(max_workers)
 
         pname = multiprocessing.current_process().name
         executor_name = f"{pname}.cell_worker"
diff --git a/requirements.txt b/requirements.txt
index 89873efe0954..291ccbd828ae 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -60,6 +60,6 @@ cursive>=0.2.1 # Apache-2.0
 retrying>=1.3.3 # Apache-2.0
 os-service-types>=1.7.0 # Apache-2.0
 python-dateutil>=2.7.0 # BSD
-futurist>=1.8.0 # Apache-2.0
+futurist>=3.2.1 # Apache-2.0
 openstacksdk>=4.4.0 # Apache-2.0
 PyYAML>=5.1 # MIT