diff --git a/samples/snippets/create_cluster.py b/samples/snippets/create_cluster.py
index f4fee7d8..633b59e8 100644
--- a/samples/snippets/create_cluster.py
+++ b/samples/snippets/create_cluster.py
@@ -29,12 +29,12 @@
 
 def create_cluster(project_id, region, cluster_name):
     """This sample walks a user through creating a Cloud Dataproc cluster
-       using the Python client library.
+    using the Python client library.
 
-       Args:
-           project_id (string): Project to use for creating resources.
-           region (string): Region where the resources should live.
-           cluster_name (string): Name to use for creating a cluster.
+    Args:
+        project_id (string): Project to use for creating resources.
+        region (string): Region where the resources should live.
+        cluster_name (string): Name to use for creating a cluster.
     """
 
     # Create a client with the endpoint set to the desired cluster region.
diff --git a/samples/snippets/instantiate_inline_workflow_template.py b/samples/snippets/instantiate_inline_workflow_template.py
index b3a40d13..cbb1a218 100644
--- a/samples/snippets/instantiate_inline_workflow_template.py
+++ b/samples/snippets/instantiate_inline_workflow_template.py
@@ -27,11 +27,11 @@
 
 def instantiate_inline_workflow_template(project_id, region):
     """This sample walks a user through submitting a workflow
-       for a Cloud Dataproc using the Python client library.
+    for a Cloud Dataproc using the Python client library.
 
-       Args:
-           project_id (string): Project to use for running the workflow.
-           region (string): Region where the workflow resources should live.
+    Args:
+        project_id (string): Project to use for running the workflow.
+        region (string): Region where the workflow resources should live.
     """
 
     # Create a client with the endpoint set to the desired region.
diff --git a/samples/snippets/list_clusters.py b/samples/snippets/list_clusters.py
index 916f1a54..3ecb8aeb 100644
--- a/samples/snippets/list_clusters.py
+++ b/samples/snippets/list_clusters.py
@@ -49,8 +49,10 @@ def main(project_id, region):
     else:
         # Use a regional gRPC endpoint. See:
         # https://cloud.google.com/dataproc/docs/concepts/regional-endpoints
-        client_transport = cluster_controller_grpc_transport.ClusterControllerGrpcTransport(
-            address="{}-dataproc.googleapis.com:443".format(region)
+        client_transport = (
+            cluster_controller_grpc_transport.ClusterControllerGrpcTransport(
+                address="{}-dataproc.googleapis.com:443".format(region)
+            )
         )
         dataproc_cluster_client = dataproc_v1.ClusterControllerClient(client_transport)
 
diff --git a/samples/snippets/submit_job.py b/samples/snippets/submit_job.py
index b70348c3..d7761b73 100644
--- a/samples/snippets/submit_job.py
+++ b/samples/snippets/submit_job.py
@@ -23,8 +23,10 @@
 
 # [START dataproc_submit_job]
 import re
+
 # [END dataproc_submit_job]
 import sys
+
 # [START dataproc_submit_job]
 
 from google.cloud import dataproc_v1 as dataproc
@@ -33,21 +35,19 @@
 
 def submit_job(project_id, region, cluster_name):
     # Create the job client.
-    job_client = dataproc.JobControllerClient(client_options={
-        'api_endpoint': '{}-dataproc.googleapis.com:443'.format(region)
-    })
+    job_client = dataproc.JobControllerClient(
+        client_options={"api_endpoint": "{}-dataproc.googleapis.com:443".format(region)}
+    )
 
     # Create the job config. 'main_jar_file_uri' can also be a
     # Google Cloud Storage URL.
     job = {
-        'placement': {
-            'cluster_name': cluster_name
+        "placement": {"cluster_name": cluster_name},
+        "spark_job": {
+            "main_class": "org.apache.spark.examples.SparkPi",
+            "jar_file_uris": ["file:///usr/lib/spark/examples/jars/spark-examples.jar"],
+            "args": ["1000"],
         },
-        'spark_job': {
-            'main_class': 'org.apache.spark.examples.SparkPi',
-            'jar_file_uris': ['file:///usr/lib/spark/examples/jars/spark-examples.jar'],
-            'args': ['1000']
-        }
     }
 
     operation = job_client.submit_job_as_operation(
@@ -67,12 +67,14 @@ def submit_job(project_id, region, cluster_name):
     )
 
     print(f"Job finished successfully: {output}")
+
+
 # [END dataproc_submit_job]
 
 
 if __name__ == "__main__":
     if len(sys.argv) < 3:
-        sys.exit('python submit_job.py project_id region cluster_name')
+        sys.exit("python submit_job.py project_id region cluster_name")
 
     project_id = sys.argv[1]
     region = sys.argv[2]
diff --git a/samples/snippets/submit_job_test.py b/samples/snippets/submit_job_test.py
index 326b38d5..6827916f 100644
--- a/samples/snippets/submit_job_test.py
+++ b/samples/snippets/submit_job_test.py
@@ -21,30 +21,24 @@
 import submit_job
 
 
-PROJECT_ID = os.environ['GOOGLE_CLOUD_PROJECT']
-REGION = 'us-central1'
-CLUSTER_NAME = 'py-sj-test-{}'.format(str(uuid.uuid4()))
+PROJECT_ID = os.environ["GOOGLE_CLOUD_PROJECT"]
+REGION = "us-central1"
+CLUSTER_NAME = "py-sj-test-{}".format(str(uuid.uuid4()))
 CLUSTER = {
-    'project_id': PROJECT_ID,
-    'cluster_name': CLUSTER_NAME,
-    'config': {
-        'master_config': {
-            'num_instances': 1,
-            'machine_type_uri': 'n1-standard-2'
-        },
-        'worker_config': {
-            'num_instances': 2,
-            'machine_type_uri': 'n1-standard-2'
-        }
-    }
+    "project_id": PROJECT_ID,
+    "cluster_name": CLUSTER_NAME,
+    "config": {
+        "master_config": {"num_instances": 1, "machine_type_uri": "n1-standard-2"},
+        "worker_config": {"num_instances": 2, "machine_type_uri": "n1-standard-2"},
+    },
 }
 
 
 @pytest.fixture(autouse=True)
 def setup_teardown():
-    cluster_client = dataproc.ClusterControllerClient(client_options={
-        'api_endpoint': '{}-dataproc.googleapis.com:443'.format(REGION)
-    })
+    cluster_client = dataproc.ClusterControllerClient(
+        client_options={"api_endpoint": "{}-dataproc.googleapis.com:443".format(REGION)}
+    )
 
     # Create the cluster.
     operation = cluster_client.create_cluster(
@@ -54,13 +48,17 @@ def setup_teardown():
 
     yield
 
-    cluster_client.delete_cluster(request={
-        "project_id": PROJECT_ID, "region": REGION, "cluster_name": CLUSTER_NAME
-    })
+    cluster_client.delete_cluster(
+        request={
+            "project_id": PROJECT_ID,
+            "region": REGION,
+            "cluster_name": CLUSTER_NAME,
+        }
+    )
 
 
 def test_submit_job(capsys):
     submit_job.submit_job(PROJECT_ID, REGION, CLUSTER_NAME)
     out, _ = capsys.readouterr()
 
-    assert 'Job finished successfully' in out
+    assert "Job finished successfully" in out
diff --git a/samples/snippets/submit_job_to_cluster.py b/samples/snippets/submit_job_to_cluster.py
index 35d329c5..68a547c4 100644
--- a/samples/snippets/submit_job_to_cluster.py
+++ b/samples/snippets/submit_job_to_cluster.py
@@ -77,8 +77,10 @@ def download_output(project, cluster_id, output_bucket, job_id):
     print("Downloading output file.")
     client = storage.Client(project=project)
     bucket = client.get_bucket(output_bucket)
-    output_blob = "google-cloud-dataproc-metainfo/{}/jobs/{}/driveroutput.000000000".format(
-        cluster_id, job_id
+    output_blob = (
+        "google-cloud-dataproc-metainfo/{}/jobs/{}/driveroutput.000000000".format(
+            cluster_id, job_id
+        )
     )
     return bucket.blob(output_blob).download_as_string()
 
@@ -230,8 +232,10 @@ def main(
         region = get_region_from_zone(zone)
         # Use a regional gRPC endpoint. See:
         # https://cloud.google.com/dataproc/docs/concepts/regional-endpoints
-        client_transport = cluster_controller_grpc_transport.ClusterControllerGrpcTransport(
-            address="{}-dataproc.googleapis.com:443".format(region)
+        client_transport = (
+            cluster_controller_grpc_transport.ClusterControllerGrpcTransport(
+                address="{}-dataproc.googleapis.com:443".format(region)
+            )
         )
         job_transport = job_controller_grpc_transport.JobControllerGrpcTransport(
             address="{}-dataproc.googleapis.com:443".format(region)
diff --git a/samples/snippets/update_cluster.py b/samples/snippets/update_cluster.py
new file mode 100644
index 00000000..f4520224
--- /dev/null
+++ b/samples/snippets/update_cluster.py
@@ -0,0 +1,78 @@
+# Copyright 2021 Google LLC
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#    http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+# This sample walks a user through updating the number of clusters using the Dataproc
+# client library.
+
+# Usage:
+#  python update_cluster.py --project_id <PROJECT_ID> --region <REGION> --cluster_name <CLUSTER_NAME>
+
+import sys
+
+# [START dataproc_update_cluster]
+from google.cloud import dataproc_v1 as dataproc
+
+
+def update_cluster(project_id, region, cluster_name, new_num_instances):
+    """This sample walks a user through updating a Cloud Dataproc cluster
+    using the Python client library.
+
+    Args:
+        project_id (str): Project to use for creating resources.
+        region (str): Region where the resources should live.
+        cluster_name (str): Name to use for creating a cluster.
+    """
+
+    # Create a client with the endpoint set to the desired cluster region.
+    client = dataproc.ClusterControllerClient(
+        client_options={"api_endpoint": f"{region}-dataproc.googleapis.com:443"}
+    )
+
+    # Get cluster you wish to update.
+    cluster = client.get_cluster(
+        project_id=project_id, region=region, cluster_name=cluster_name
+    )
+
+    # Update number of clusters
+    mask = {"paths": {"config.worker_config.num_instances": str(new_num_instances)}}
+
+    # Update cluster config
+    cluster.config.worker_config.num_instances = new_num_instances
+
+    # Update cluster
+    operation = client.update_cluster(
+        project_id=project_id,
+        region=region,
+        cluster=cluster,
+        cluster_name=cluster_name,
+        update_mask=mask,
+    )
+
+    # Output a success message.
+    updated_cluster = operation.result()
+    print(f"Cluster was updated successfully: {updated_cluster.cluster_name}")
+
+
+# [END dataproc_update_cluster]
+
+
+if __name__ == "__main__":
+    if len(sys.argv) < 5:
+        sys.exit("python update_cluster.py project_id region cluster_name")
+
+        project_id = sys.argv[1]
+        region = sys.argv[2]
+        cluster_name = sys.argv[3]
+        new_num_instances = sys.argv[4]
+        update_cluster(project_id, region, cluster_name)
diff --git a/samples/snippets/update_cluster_test.py b/samples/snippets/update_cluster_test.py
new file mode 100644
index 00000000..9c608ac4
--- /dev/null
+++ b/samples/snippets/update_cluster_test.py
@@ -0,0 +1,80 @@
+# Copyright 2021 Google LLC
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#    http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+# This sample walks a user through updating the number of clusters using the Dataproc
+# client library.
+
+
+import os
+import uuid
+
+from google.cloud.dataproc_v1.services.cluster_controller.client import (
+    ClusterControllerClient,
+)
+import pytest
+
+import update_cluster
+
+
+PROJECT_ID = os.environ["GOOGLE_CLOUD_PROJECT"]
+REGION = "us-central1"
+CLUSTER_NAME = f"py-cc-test-{str(uuid.uuid4())}"
+NEW_NUM_INSTANCES = 5
+CLUSTER = {
+    "project_id": PROJECT_ID,
+    "cluster_name": CLUSTER_NAME,
+    "config": {
+        "master_config": {"num_instances": 1, "machine_type_uri": "n1-standard-2"},
+        "worker_config": {"num_instances": 2, "machine_type_uri": "n1-standard-2"},
+    },
+}
+
+
+@pytest.fixture(autouse=True)
+def setup_teardown(cluster_client):
+    # Create the cluster.
+    operation = cluster_client.create_cluster(
+        request={"project_id": PROJECT_ID, "region": REGION, "cluster": CLUSTER}
+    )
+    operation.result()
+
+    yield
+
+    cluster_client.delete_cluster(
+        request={
+            "project_id": PROJECT_ID,
+            "region": REGION,
+            "cluster_name": CLUSTER_NAME,
+        }
+    )
+
+
+@pytest.fixture
+def cluster_client():
+    cluster_client = ClusterControllerClient(
+        client_options={"api_endpoint": "{}-dataproc.googleapis.com:443".format(REGION)}
+    )
+    return cluster_client
+
+
+def test_update_cluster(capsys, cluster_client: ClusterControllerClient):
+    # Wrapper function for client library function
+    update_cluster.update_cluster(PROJECT_ID, REGION, CLUSTER_NAME, NEW_NUM_INSTANCES)
+    new_num_cluster = cluster_client.get_cluster(
+        project_id=PROJECT_ID, region=REGION, cluster_name=CLUSTER_NAME
+    )
+
+    out, _ = capsys.readouterr()
+    assert CLUSTER_NAME in out
+    assert new_num_cluster.config.worker_config.num_instances == NEW_NUM_INSTANCES