ashb commented on a change in pull request #8701:
URL: https://github.com/apache/airflow/pull/8701#discussion_r455349067



##########
File path: airflow/providers/amazon/aws/hooks/elasticache.py
##########
@@ -0,0 +1,265 @@
+#
+# Licensed to the Apache Software Foundation (ASF) under one
+# or more contributor license agreements.  See the NOTICE file
+# distributed with this work for additional information
+# regarding copyright ownership.  The ASF licenses this file
+# to you 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.
+
+from time import sleep
+
+from airflow.exceptions import AirflowException
+from airflow.providers.amazon.aws.hooks.base_aws import AwsBaseHook
+
+
+class ElastiCacheHook(AwsBaseHook):
+    """
+    Interact with AWS ElastiCache
+    """
+
+    # Constants for ElastiCache describe API response keys
+    REPLICATION_GROUPS = 'ReplicationGroups'
+    REPLICATION_GROUP = 'ReplicationGroup'
+    STATUS = 'Status'
+
+    # Constants for ElastiCache replication group status
+    STATUS_CREATING = 'creating'
+    STATUS_AVAILABLE = 'available'
+    STATUS_DELETING = 'deleting'
+    STATUS_CREATE_FAILED = 'create-failed'
+    STATUS_MODIFYING = 'modifying'
+    STATUS_SNAPSHOTTING = 'snapshotting'
+
+    def __init__(
+        self, max_retries=10, exponential_back_off_factor=1, 
initial_poke_interval=60, *args, **kwargs
+    ):
+        """
+        :param max_retries: Max tries for checking availability of and 
deleting replication group
+        :param exponential_back_off_factor: Factor for deciding next sleep time
+        :param initial_poke_interval: Initial sleep time in seconds
+        """
+        self.max_retries = max_retries
+        self.exponential_back_off_factor = exponential_back_off_factor
+        self.initial_poke_interval = initial_poke_interval
+
+        super().__init__(client_type='elasticache', *args, **kwargs)
+
+    def create_replication_group(self, config):
+        """
+        Call ElastiCache API for creating a replication group
+
+        :param config: Python dictionary to use as config for creating 
replication group
+        :return: Response from ElastiCache create replication group API
+        """
+        return self.conn.create_replication_group(**config)
+
+    def delete_replication_group(self, replication_group_id):
+        """
+        Call ElastiCache API for deleting a replication group
+
+        :param replication_group_id: ID of replication group to delete
+        :return: Response from ElastiCache delete replication group API
+        """
+        return 
self.conn.delete_replication_group(ReplicationGroupId=replication_group_id)
+
+    def describe_replication_group(self, replication_group_id):
+        """
+        Call ElastiCache API for describing a replication group
+
+        :param replication_group_id: ID of replication group to describe
+        :return: Response from ElastiCache describe replication group API
+        """
+        return 
self.conn.describe_replication_groups(ReplicationGroupId=replication_group_id)
+
+    def get_replication_group_status(self, replication_group_id):
+        """
+        Get current status of replication group
+
+        :param replication_group_id: ID of replication group to check for 
status
+        :return: Current status of replication group
+        """
+        return 
self.describe_replication_group(replication_group_id)[self.REPLICATION_GROUPS][0][self.STATUS]

Review comment:
       ```suggestion
           return 
self.describe_replication_group(replication_group_id)["ReplicationGroups"][0]["Status"]
   ```

##########
File path: airflow/providers/amazon/aws/hooks/elasticache.py
##########
@@ -0,0 +1,265 @@
+#
+# Licensed to the Apache Software Foundation (ASF) under one
+# or more contributor license agreements.  See the NOTICE file
+# distributed with this work for additional information
+# regarding copyright ownership.  The ASF licenses this file
+# to you 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.
+
+from time import sleep
+
+from airflow.exceptions import AirflowException
+from airflow.providers.amazon.aws.hooks.base_aws import AwsBaseHook
+
+
+class ElastiCacheHook(AwsBaseHook):
+    """
+    Interact with AWS ElastiCache
+    """
+
+    # Constants for ElastiCache describe API response keys
+    REPLICATION_GROUPS = 'ReplicationGroups'
+    REPLICATION_GROUP = 'ReplicationGroup'
+    STATUS = 'Status'
+
+    # Constants for ElastiCache replication group status
+    STATUS_CREATING = 'creating'
+    STATUS_AVAILABLE = 'available'
+    STATUS_DELETING = 'deleting'
+    STATUS_CREATE_FAILED = 'create-failed'
+    STATUS_MODIFYING = 'modifying'
+    STATUS_SNAPSHOTTING = 'snapshotting'
+
+    def __init__(
+        self, max_retries=10, exponential_back_off_factor=1, 
initial_poke_interval=60, *args, **kwargs
+    ):
+        """
+        :param max_retries: Max tries for checking availability of and 
deleting replication group
+        :param exponential_back_off_factor: Factor for deciding next sleep time
+        :param initial_poke_interval: Initial sleep time in seconds
+        """
+        self.max_retries = max_retries
+        self.exponential_back_off_factor = exponential_back_off_factor
+        self.initial_poke_interval = initial_poke_interval
+
+        super().__init__(client_type='elasticache', *args, **kwargs)
+
+    def create_replication_group(self, config):
+        """
+        Call ElastiCache API for creating a replication group
+
+        :param config: Python dictionary to use as config for creating 
replication group
+        :return: Response from ElastiCache create replication group API
+        """
+        return self.conn.create_replication_group(**config)
+
+    def delete_replication_group(self, replication_group_id):
+        """
+        Call ElastiCache API for deleting a replication group
+
+        :param replication_group_id: ID of replication group to delete
+        :return: Response from ElastiCache delete replication group API
+        """
+        return 
self.conn.delete_replication_group(ReplicationGroupId=replication_group_id)
+
+    def describe_replication_group(self, replication_group_id):
+        """
+        Call ElastiCache API for describing a replication group
+
+        :param replication_group_id: ID of replication group to describe
+        :return: Response from ElastiCache describe replication group API
+        """
+        return 
self.conn.describe_replication_groups(ReplicationGroupId=replication_group_id)
+
+    def get_replication_group_status(self, replication_group_id):
+        """
+        Get current status of replication group
+
+        :param replication_group_id: ID of replication group to check for 
status
+        :return: Current status of replication group
+        """
+        return 
self.describe_replication_group(replication_group_id)[self.REPLICATION_GROUPS][0][self.STATUS]
+
+    def is_replication_group_available(self, replication_group_id):
+        """
+        Helper for checking if replication group is available or not
+
+        :param replication_group_id: ID of replication group to check for 
availability
+        :return: True if available else False
+        """
+        return self.get_replication_group_status(replication_group_id) == 
self.STATUS_AVAILABLE

Review comment:
       ```suggestion
           return self.get_replication_group_status(replication_group_id) == 
"available"
   ```

##########
File path: airflow/providers/amazon/aws/hooks/elasticache.py
##########
@@ -0,0 +1,265 @@
+#
+# Licensed to the Apache Software Foundation (ASF) under one
+# or more contributor license agreements.  See the NOTICE file
+# distributed with this work for additional information
+# regarding copyright ownership.  The ASF licenses this file
+# to you 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.
+
+from time import sleep
+
+from airflow.exceptions import AirflowException
+from airflow.providers.amazon.aws.hooks.base_aws import AwsBaseHook
+
+
+class ElastiCacheHook(AwsBaseHook):
+    """
+    Interact with AWS ElastiCache
+    """
+
+    # Constants for ElastiCache describe API response keys
+    REPLICATION_GROUPS = 'ReplicationGroups'
+    REPLICATION_GROUP = 'ReplicationGroup'
+    STATUS = 'Status'
+
+    # Constants for ElastiCache replication group status
+    STATUS_CREATING = 'creating'
+    STATUS_AVAILABLE = 'available'
+    STATUS_DELETING = 'deleting'
+    STATUS_CREATE_FAILED = 'create-failed'
+    STATUS_MODIFYING = 'modifying'
+    STATUS_SNAPSHOTTING = 'snapshotting'
+
+    def __init__(
+        self, max_retries=10, exponential_back_off_factor=1, 
initial_poke_interval=60, *args, **kwargs
+    ):
+        """
+        :param max_retries: Max tries for checking availability of and 
deleting replication group
+        :param exponential_back_off_factor: Factor for deciding next sleep time
+        :param initial_poke_interval: Initial sleep time in seconds
+        """
+        self.max_retries = max_retries
+        self.exponential_back_off_factor = exponential_back_off_factor
+        self.initial_poke_interval = initial_poke_interval
+
+        super().__init__(client_type='elasticache', *args, **kwargs)
+
+    def create_replication_group(self, config):
+        """
+        Call ElastiCache API for creating a replication group
+
+        :param config: Python dictionary to use as config for creating 
replication group
+        :return: Response from ElastiCache create replication group API
+        """
+        return self.conn.create_replication_group(**config)
+
+    def delete_replication_group(self, replication_group_id):
+        """
+        Call ElastiCache API for deleting a replication group
+
+        :param replication_group_id: ID of replication group to delete
+        :return: Response from ElastiCache delete replication group API
+        """
+        return 
self.conn.delete_replication_group(ReplicationGroupId=replication_group_id)
+
+    def describe_replication_group(self, replication_group_id):
+        """
+        Call ElastiCache API for describing a replication group
+
+        :param replication_group_id: ID of replication group to describe
+        :return: Response from ElastiCache describe replication group API
+        """
+        return 
self.conn.describe_replication_groups(ReplicationGroupId=replication_group_id)
+
+    def get_replication_group_status(self, replication_group_id):
+        """
+        Get current status of replication group
+
+        :param replication_group_id: ID of replication group to check for 
status
+        :return: Current status of replication group
+        """
+        return 
self.describe_replication_group(replication_group_id)[self.REPLICATION_GROUPS][0][self.STATUS]
+
+    def is_replication_group_available(self, replication_group_id):
+        """
+        Helper for checking if replication group is available or not
+
+        :param replication_group_id: ID of replication group to check for 
availability
+        :return: True if available else False
+        """
+        return self.get_replication_group_status(replication_group_id) == 
self.STATUS_AVAILABLE
+
+    def _has_reached_terminal_state(self, replication_group_id):
+        """
+        Helper for checking if we should stop poking replication group for 
availability or not
+
+        :param replication_group_id: ID of replication group to check
+        :return: Flag to check if availability check should be stopped or not 
and current status
+        """
+        status = 
self.get_replication_group_status(replication_group_id=replication_group_id)
+
+        return status in (
+            self.STATUS_AVAILABLE,
+            self.STATUS_CREATE_FAILED,
+            self.STATUS_DELETING
+        ), status
+
+    def wait_for_availability(
+        self,
+        replication_group_id,
+        initial_sleep_time=None,
+        exponential_back_off_factor=None,
+        max_retries=None
+    ):
+        """
+        Check if replication is available or not by performing a describe over 
it
+
+        :param max_retries: Max tries for checking availability of replication 
group
+        :param exponential_back_off_factor: Factor for deciding next sleep time
+        :param initial_sleep_time: Initial sleep time in seconds
+        :param replication_group_id: ID of replication group to check for 
availability
+        :return: True if replication is available else False
+        """
+        sleep_time = initial_sleep_time or self.initial_poke_interval
+        exponential_back_off_factor = exponential_back_off_factor or 
self.exponential_back_off_factor
+        max_retries = max_retries or self.max_retries
+        num_retries = 0
+        status = self.STATUS_CREATE_FAILED
+
+        while num_retries < max_retries:
+            stop_poking, status = 
self._has_reached_terminal_state(replication_group_id=replication_group_id)
+
+            self.log.info(
+                'Current status of replication group with ID : %s is %s',
+                replication_group_id,
+                status
+            )
+
+            if stop_poking:
+                break
+
+            num_retries += 1
+
+            self.log.info('Poke retry: %s. Sleep time: %s. Sleeping...', 
num_retries, sleep_time)
+
+            sleep(sleep_time)
+
+            sleep_time = sleep_time * exponential_back_off_factor
+
+        if status != self.STATUS_AVAILABLE:

Review comment:
       ```suggestion
           if status != "available":
   ```

##########
File path: airflow/providers/amazon/aws/hooks/elasticache.py
##########
@@ -0,0 +1,265 @@
+#
+# Licensed to the Apache Software Foundation (ASF) under one
+# or more contributor license agreements.  See the NOTICE file
+# distributed with this work for additional information
+# regarding copyright ownership.  The ASF licenses this file
+# to you 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.
+
+from time import sleep
+
+from airflow.exceptions import AirflowException
+from airflow.providers.amazon.aws.hooks.base_aws import AwsBaseHook
+
+
+class ElastiCacheHook(AwsBaseHook):
+    """
+    Interact with AWS ElastiCache
+    """
+
+    # Constants for ElastiCache describe API response keys
+    REPLICATION_GROUPS = 'ReplicationGroups'
+    REPLICATION_GROUP = 'ReplicationGroup'
+    STATUS = 'Status'
+
+    # Constants for ElastiCache replication group status
+    STATUS_CREATING = 'creating'
+    STATUS_AVAILABLE = 'available'
+    STATUS_DELETING = 'deleting'
+    STATUS_CREATE_FAILED = 'create-failed'
+    STATUS_MODIFYING = 'modifying'
+    STATUS_SNAPSHOTTING = 'snapshotting'
+
+    def __init__(
+        self, max_retries=10, exponential_back_off_factor=1, 
initial_poke_interval=60, *args, **kwargs
+    ):
+        """
+        :param max_retries: Max tries for checking availability of and 
deleting replication group
+        :param exponential_back_off_factor: Factor for deciding next sleep time
+        :param initial_poke_interval: Initial sleep time in seconds
+        """
+        self.max_retries = max_retries
+        self.exponential_back_off_factor = exponential_back_off_factor
+        self.initial_poke_interval = initial_poke_interval
+
+        super().__init__(client_type='elasticache', *args, **kwargs)
+
+    def create_replication_group(self, config):
+        """
+        Call ElastiCache API for creating a replication group
+
+        :param config: Python dictionary to use as config for creating 
replication group
+        :return: Response from ElastiCache create replication group API
+        """
+        return self.conn.create_replication_group(**config)
+
+    def delete_replication_group(self, replication_group_id):
+        """
+        Call ElastiCache API for deleting a replication group
+
+        :param replication_group_id: ID of replication group to delete
+        :return: Response from ElastiCache delete replication group API
+        """
+        return 
self.conn.delete_replication_group(ReplicationGroupId=replication_group_id)
+
+    def describe_replication_group(self, replication_group_id):
+        """
+        Call ElastiCache API for describing a replication group
+
+        :param replication_group_id: ID of replication group to describe
+        :return: Response from ElastiCache describe replication group API
+        """
+        return 
self.conn.describe_replication_groups(ReplicationGroupId=replication_group_id)
+
+    def get_replication_group_status(self, replication_group_id):
+        """
+        Get current status of replication group
+
+        :param replication_group_id: ID of replication group to check for 
status
+        :return: Current status of replication group
+        """
+        return 
self.describe_replication_group(replication_group_id)[self.REPLICATION_GROUPS][0][self.STATUS]
+
+    def is_replication_group_available(self, replication_group_id):
+        """
+        Helper for checking if replication group is available or not
+
+        :param replication_group_id: ID of replication group to check for 
availability
+        :return: True if available else False
+        """
+        return self.get_replication_group_status(replication_group_id) == 
self.STATUS_AVAILABLE
+
+    def _has_reached_terminal_state(self, replication_group_id):
+        """
+        Helper for checking if we should stop poking replication group for 
availability or not
+
+        :param replication_group_id: ID of replication group to check
+        :return: Flag to check if availability check should be stopped or not 
and current status
+        """
+        status = 
self.get_replication_group_status(replication_group_id=replication_group_id)
+
+        return status in (
+            self.STATUS_AVAILABLE,
+            self.STATUS_CREATE_FAILED,
+            self.STATUS_DELETING
+        ), status
+
+    def wait_for_availability(
+        self,
+        replication_group_id,
+        initial_sleep_time=None,
+        exponential_back_off_factor=None,
+        max_retries=None
+    ):
+        """
+        Check if replication is available or not by performing a describe over 
it
+
+        :param max_retries: Max tries for checking availability of replication 
group
+        :param exponential_back_off_factor: Factor for deciding next sleep time
+        :param initial_sleep_time: Initial sleep time in seconds
+        :param replication_group_id: ID of replication group to check for 
availability

Review comment:
       Could you add types to these please?
   
   ```suggestion
           :param max_retries: Max tries for checking availability of 
replication group
           :type max_retries: int
           :param exponential_back_off_factor: Factor for deciding next sleep 
time
           :type exponential_back_off_factor: ...
           :param initial_sleep_time: Initial sleep time in seconds
           :type initial_sleep_time:
           :param replication_group_id: ID of replication group to check for 
availability
           :type replication_group_id:
   ```
   
   Same for all the other public methods too please.

##########
File path: airflow/providers/amazon/aws/hooks/elasticache.py
##########
@@ -0,0 +1,265 @@
+#
+# Licensed to the Apache Software Foundation (ASF) under one
+# or more contributor license agreements.  See the NOTICE file
+# distributed with this work for additional information
+# regarding copyright ownership.  The ASF licenses this file
+# to you 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.
+
+from time import sleep
+
+from airflow.exceptions import AirflowException
+from airflow.providers.amazon.aws.hooks.base_aws import AwsBaseHook
+
+
+class ElastiCacheHook(AwsBaseHook):
+    """
+    Interact with AWS ElastiCache
+    """
+
+    # Constants for ElastiCache describe API response keys
+    REPLICATION_GROUPS = 'ReplicationGroups'
+    REPLICATION_GROUP = 'ReplicationGroup'
+    STATUS = 'Status'
+
+    # Constants for ElastiCache replication group status
+    STATUS_CREATING = 'creating'
+    STATUS_AVAILABLE = 'available'
+    STATUS_DELETING = 'deleting'
+    STATUS_CREATE_FAILED = 'create-failed'
+    STATUS_MODIFYING = 'modifying'
+    STATUS_SNAPSHOTTING = 'snapshotting'
+
+    def __init__(
+        self, max_retries=10, exponential_back_off_factor=1, 
initial_poke_interval=60, *args, **kwargs
+    ):
+        """
+        :param max_retries: Max tries for checking availability of and 
deleting replication group
+        :param exponential_back_off_factor: Factor for deciding next sleep time
+        :param initial_poke_interval: Initial sleep time in seconds
+        """
+        self.max_retries = max_retries
+        self.exponential_back_off_factor = exponential_back_off_factor
+        self.initial_poke_interval = initial_poke_interval
+
+        super().__init__(client_type='elasticache', *args, **kwargs)
+
+    def create_replication_group(self, config):
+        """
+        Call ElastiCache API for creating a replication group
+
+        :param config: Python dictionary to use as config for creating 
replication group
+        :return: Response from ElastiCache create replication group API
+        """
+        return self.conn.create_replication_group(**config)
+
+    def delete_replication_group(self, replication_group_id):
+        """
+        Call ElastiCache API for deleting a replication group
+
+        :param replication_group_id: ID of replication group to delete
+        :return: Response from ElastiCache delete replication group API
+        """
+        return 
self.conn.delete_replication_group(ReplicationGroupId=replication_group_id)
+
+    def describe_replication_group(self, replication_group_id):
+        """
+        Call ElastiCache API for describing a replication group
+
+        :param replication_group_id: ID of replication group to describe
+        :return: Response from ElastiCache describe replication group API
+        """
+        return 
self.conn.describe_replication_groups(ReplicationGroupId=replication_group_id)
+
+    def get_replication_group_status(self, replication_group_id):
+        """
+        Get current status of replication group
+
+        :param replication_group_id: ID of replication group to check for 
status
+        :return: Current status of replication group
+        """
+        return 
self.describe_replication_group(replication_group_id)[self.REPLICATION_GROUPS][0][self.STATUS]
+
+    def is_replication_group_available(self, replication_group_id):
+        """
+        Helper for checking if replication group is available or not
+
+        :param replication_group_id: ID of replication group to check for 
availability
+        :return: True if available else False
+        """
+        return self.get_replication_group_status(replication_group_id) == 
self.STATUS_AVAILABLE
+
+    def _has_reached_terminal_state(self, replication_group_id):
+        """
+        Helper for checking if we should stop poking replication group for 
availability or not
+
+        :param replication_group_id: ID of replication group to check
+        :return: Flag to check if availability check should be stopped or not 
and current status
+        """
+        status = 
self.get_replication_group_status(replication_group_id=replication_group_id)
+
+        return status in (
+            self.STATUS_AVAILABLE,
+            self.STATUS_CREATE_FAILED,
+            self.STATUS_DELETING
+        ), status
+
+    def wait_for_availability(
+        self,
+        replication_group_id,
+        initial_sleep_time=None,
+        exponential_back_off_factor=None,
+        max_retries=None
+    ):
+        """
+        Check if replication is available or not by performing a describe over 
it
+
+        :param max_retries: Max tries for checking availability of replication 
group
+        :param exponential_back_off_factor: Factor for deciding next sleep time
+        :param initial_sleep_time: Initial sleep time in seconds
+        :param replication_group_id: ID of replication group to check for 
availability
+        :return: True if replication is available else False
+        """
+        sleep_time = initial_sleep_time or self.initial_poke_interval
+        exponential_back_off_factor = exponential_back_off_factor or 
self.exponential_back_off_factor
+        max_retries = max_retries or self.max_retries
+        num_retries = 0
+        status = self.STATUS_CREATE_FAILED
+
+        while num_retries < max_retries:
+            stop_poking, status = 
self._has_reached_terminal_state(replication_group_id=replication_group_id)
+
+            self.log.info(
+                'Current status of replication group with ID : %s is %s',
+                replication_group_id,
+                status
+            )
+
+            if stop_poking:
+                break
+
+            num_retries += 1
+
+            self.log.info('Poke retry: %s. Sleep time: %s. Sleeping...', 
num_retries, sleep_time)
+
+            sleep(sleep_time)
+
+            sleep_time = sleep_time * exponential_back_off_factor
+
+        if status != self.STATUS_AVAILABLE:
+            self.log.warning('Replication group is not available. Current 
status : "%s"', status)
+
+            return False
+
+        return True
+
+    def wait_for_deletion(
+        self,
+        replication_group_id,
+        initial_sleep_time=None,
+        exponential_back_off_factor=None,
+        max_retries=None
+    ):
+        """
+        Helper for deleting a replication group ensuring it is either deleted 
or can't be deleted
+
+        :param replication_group_id: ID of replication to delete
+        :param max_retries: Max tries for checking availability of replication 
group
+        :param exponential_back_off_factor: Factor for deciding next sleep time
+        :param initial_sleep_time: Initial sleep time in second
+        :return: Response from ElastiCache delete replication group API and 
flag to identify if deleted or not
+        """
+        deleted = False
+        sleep_time = initial_sleep_time or self.initial_poke_interval
+        exponential_back_off_factor = exponential_back_off_factor or 
self.exponential_back_off_factor
+        max_retries = max_retries or self.max_retries
+        num_retries = 0
+        response = None
+
+        while not deleted and num_retries < max_retries:
+            try:
+                status = 
self.get_replication_group_status(replication_group_id=replication_group_id)
+
+                self.log.info(
+                    'Current status of replication group with ID : %s is %s',
+                    replication_group_id,
+                    status
+                )
+
+                # Can only delete if status is `available`
+                # Status becomes `deleting` after this call so this will only 
run once
+                if status == self.STATUS_AVAILABLE:
+                    response = 
self.delete_replication_group(replication_group_id=replication_group_id)
+
+            except self.conn.exceptions.ReplicationGroupNotFoundFault:
+                self.log.info("Replication group with ID : '%s' does not 
exist", replication_group_id)
+
+                deleted = True
+
+            # This should never occur as we only issue a delete request when 
status is `available`
+            # which is a valid status for deletion. Still handling for safety.
+            except self.conn.exceptions.InvalidReplicationGroupStateFault as 
exp:
+                # status      Error Response
+                # creating  - Cache cluster <cluster_id> is not in a valid 
state to be deleted.
+                # deleting  - Replication group <replication_group_id> has 
status deleting which is not valid
+                #             for deletion.
+                # modifying - Replication group <replication_group_id> has 
status deleting which is not valid
+                #             for deletion.
+
+                message = exp.response['Error']['Message']
+
+                self.log.info('Received message : %s', message)

Review comment:
       (Or maybe at warning?)

##########
File path: airflow/providers/amazon/aws/hooks/elasticache.py
##########
@@ -0,0 +1,265 @@
+#
+# Licensed to the Apache Software Foundation (ASF) under one
+# or more contributor license agreements.  See the NOTICE file
+# distributed with this work for additional information
+# regarding copyright ownership.  The ASF licenses this file
+# to you 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.
+
+from time import sleep
+
+from airflow.exceptions import AirflowException
+from airflow.providers.amazon.aws.hooks.base_aws import AwsBaseHook
+
+
+class ElastiCacheHook(AwsBaseHook):
+    """
+    Interact with AWS ElastiCache
+    """
+
+    # Constants for ElastiCache describe API response keys
+    REPLICATION_GROUPS = 'ReplicationGroups'
+    REPLICATION_GROUP = 'ReplicationGroup'
+    STATUS = 'Status'
+
+    # Constants for ElastiCache replication group status
+    STATUS_CREATING = 'creating'
+    STATUS_AVAILABLE = 'available'
+    STATUS_DELETING = 'deleting'
+    STATUS_CREATE_FAILED = 'create-failed'
+    STATUS_MODIFYING = 'modifying'
+    STATUS_SNAPSHOTTING = 'snapshotting'

Review comment:
       ```suggestion
   ```
   
   These constants make it harder to understand the code and isn't the style we 
use in Airfow, please use the string literals directly.

##########
File path: airflow/providers/amazon/aws/hooks/elasticache.py
##########
@@ -0,0 +1,265 @@
+#
+# Licensed to the Apache Software Foundation (ASF) under one
+# or more contributor license agreements.  See the NOTICE file
+# distributed with this work for additional information
+# regarding copyright ownership.  The ASF licenses this file
+# to you 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.
+
+from time import sleep
+
+from airflow.exceptions import AirflowException
+from airflow.providers.amazon.aws.hooks.base_aws import AwsBaseHook
+
+
+class ElastiCacheHook(AwsBaseHook):
+    """
+    Interact with AWS ElastiCache
+    """
+
+    # Constants for ElastiCache describe API response keys
+    REPLICATION_GROUPS = 'ReplicationGroups'
+    REPLICATION_GROUP = 'ReplicationGroup'
+    STATUS = 'Status'
+
+    # Constants for ElastiCache replication group status
+    STATUS_CREATING = 'creating'
+    STATUS_AVAILABLE = 'available'
+    STATUS_DELETING = 'deleting'
+    STATUS_CREATE_FAILED = 'create-failed'
+    STATUS_MODIFYING = 'modifying'
+    STATUS_SNAPSHOTTING = 'snapshotting'
+
+    def __init__(
+        self, max_retries=10, exponential_back_off_factor=1, 
initial_poke_interval=60, *args, **kwargs
+    ):
+        """
+        :param max_retries: Max tries for checking availability of and 
deleting replication group
+        :param exponential_back_off_factor: Factor for deciding next sleep time
+        :param initial_poke_interval: Initial sleep time in seconds
+        """
+        self.max_retries = max_retries
+        self.exponential_back_off_factor = exponential_back_off_factor
+        self.initial_poke_interval = initial_poke_interval
+
+        super().__init__(client_type='elasticache', *args, **kwargs)
+
+    def create_replication_group(self, config):
+        """
+        Call ElastiCache API for creating a replication group
+
+        :param config: Python dictionary to use as config for creating 
replication group
+        :return: Response from ElastiCache create replication group API
+        """
+        return self.conn.create_replication_group(**config)
+
+    def delete_replication_group(self, replication_group_id):
+        """
+        Call ElastiCache API for deleting a replication group
+
+        :param replication_group_id: ID of replication group to delete
+        :return: Response from ElastiCache delete replication group API
+        """
+        return 
self.conn.delete_replication_group(ReplicationGroupId=replication_group_id)
+
+    def describe_replication_group(self, replication_group_id):
+        """
+        Call ElastiCache API for describing a replication group
+
+        :param replication_group_id: ID of replication group to describe
+        :return: Response from ElastiCache describe replication group API
+        """
+        return 
self.conn.describe_replication_groups(ReplicationGroupId=replication_group_id)
+
+    def get_replication_group_status(self, replication_group_id):
+        """
+        Get current status of replication group
+
+        :param replication_group_id: ID of replication group to check for 
status
+        :return: Current status of replication group
+        """
+        return 
self.describe_replication_group(replication_group_id)[self.REPLICATION_GROUPS][0][self.STATUS]
+
+    def is_replication_group_available(self, replication_group_id):
+        """
+        Helper for checking if replication group is available or not
+
+        :param replication_group_id: ID of replication group to check for 
availability
+        :return: True if available else False
+        """
+        return self.get_replication_group_status(replication_group_id) == 
self.STATUS_AVAILABLE
+
+    def _has_reached_terminal_state(self, replication_group_id):
+        """
+        Helper for checking if we should stop poking replication group for 
availability or not
+
+        :param replication_group_id: ID of replication group to check
+        :return: Flag to check if availability check should be stopped or not 
and current status
+        """
+        status = 
self.get_replication_group_status(replication_group_id=replication_group_id)
+
+        return status in (
+            self.STATUS_AVAILABLE,
+            self.STATUS_CREATE_FAILED,
+            self.STATUS_DELETING
+        ), status
+
+    def wait_for_availability(
+        self,
+        replication_group_id,
+        initial_sleep_time=None,
+        exponential_back_off_factor=None,
+        max_retries=None
+    ):
+        """
+        Check if replication is available or not by performing a describe over 
it
+
+        :param max_retries: Max tries for checking availability of replication 
group
+        :param exponential_back_off_factor: Factor for deciding next sleep time
+        :param initial_sleep_time: Initial sleep time in seconds
+        :param replication_group_id: ID of replication group to check for 
availability
+        :return: True if replication is available else False
+        """
+        sleep_time = initial_sleep_time or self.initial_poke_interval
+        exponential_back_off_factor = exponential_back_off_factor or 
self.exponential_back_off_factor
+        max_retries = max_retries or self.max_retries
+        num_retries = 0
+        status = self.STATUS_CREATE_FAILED

Review comment:
       ```suggestion
           status = "not-found"
   ```

##########
File path: airflow/providers/amazon/aws/hooks/elasticache.py
##########
@@ -0,0 +1,265 @@
+#
+# Licensed to the Apache Software Foundation (ASF) under one
+# or more contributor license agreements.  See the NOTICE file
+# distributed with this work for additional information
+# regarding copyright ownership.  The ASF licenses this file
+# to you 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.
+
+from time import sleep
+
+from airflow.exceptions import AirflowException
+from airflow.providers.amazon.aws.hooks.base_aws import AwsBaseHook
+
+
+class ElastiCacheHook(AwsBaseHook):
+    """
+    Interact with AWS ElastiCache
+    """
+
+    # Constants for ElastiCache describe API response keys
+    REPLICATION_GROUPS = 'ReplicationGroups'
+    REPLICATION_GROUP = 'ReplicationGroup'
+    STATUS = 'Status'
+
+    # Constants for ElastiCache replication group status
+    STATUS_CREATING = 'creating'
+    STATUS_AVAILABLE = 'available'
+    STATUS_DELETING = 'deleting'
+    STATUS_CREATE_FAILED = 'create-failed'
+    STATUS_MODIFYING = 'modifying'
+    STATUS_SNAPSHOTTING = 'snapshotting'
+
+    def __init__(
+        self, max_retries=10, exponential_back_off_factor=1, 
initial_poke_interval=60, *args, **kwargs
+    ):
+        """
+        :param max_retries: Max tries for checking availability of and 
deleting replication group
+        :param exponential_back_off_factor: Factor for deciding next sleep time
+        :param initial_poke_interval: Initial sleep time in seconds
+        """
+        self.max_retries = max_retries
+        self.exponential_back_off_factor = exponential_back_off_factor
+        self.initial_poke_interval = initial_poke_interval
+
+        super().__init__(client_type='elasticache', *args, **kwargs)
+
+    def create_replication_group(self, config):
+        """
+        Call ElastiCache API for creating a replication group
+
+        :param config: Python dictionary to use as config for creating 
replication group
+        :return: Response from ElastiCache create replication group API
+        """
+        return self.conn.create_replication_group(**config)
+
+    def delete_replication_group(self, replication_group_id):
+        """
+        Call ElastiCache API for deleting a replication group
+
+        :param replication_group_id: ID of replication group to delete
+        :return: Response from ElastiCache delete replication group API
+        """
+        return 
self.conn.delete_replication_group(ReplicationGroupId=replication_group_id)
+
+    def describe_replication_group(self, replication_group_id):
+        """
+        Call ElastiCache API for describing a replication group
+
+        :param replication_group_id: ID of replication group to describe
+        :return: Response from ElastiCache describe replication group API
+        """
+        return 
self.conn.describe_replication_groups(ReplicationGroupId=replication_group_id)
+
+    def get_replication_group_status(self, replication_group_id):
+        """
+        Get current status of replication group
+
+        :param replication_group_id: ID of replication group to check for 
status
+        :return: Current status of replication group
+        """
+        return 
self.describe_replication_group(replication_group_id)[self.REPLICATION_GROUPS][0][self.STATUS]
+
+    def is_replication_group_available(self, replication_group_id):
+        """
+        Helper for checking if replication group is available or not
+
+        :param replication_group_id: ID of replication group to check for 
availability
+        :return: True if available else False
+        """
+        return self.get_replication_group_status(replication_group_id) == 
self.STATUS_AVAILABLE
+
+    def _has_reached_terminal_state(self, replication_group_id):
+        """
+        Helper for checking if we should stop poking replication group for 
availability or not
+
+        :param replication_group_id: ID of replication group to check
+        :return: Flag to check if availability check should be stopped or not 
and current status
+        """
+        status = 
self.get_replication_group_status(replication_group_id=replication_group_id)
+
+        return status in (
+            self.STATUS_AVAILABLE,
+            self.STATUS_CREATE_FAILED,
+            self.STATUS_DELETING
+        ), status

Review comment:
       ```suggestion
           return status in (
               "available",
               "create-failed",
               "deleting"
           ), status
   ```
   
   This one could be worth extracting to a class variable:
   
   ```python
       TERMINAL_STATES = frozenset({"available", "create-failed", "deleting"})
   ```
   
   And then this becomes
   
   ```suggestion
           return status in self.TERMINAL_STATES, status
   ```

##########
File path: airflow/providers/amazon/aws/hooks/elasticache.py
##########
@@ -0,0 +1,265 @@
+#
+# Licensed to the Apache Software Foundation (ASF) under one
+# or more contributor license agreements.  See the NOTICE file
+# distributed with this work for additional information
+# regarding copyright ownership.  The ASF licenses this file
+# to you 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.
+
+from time import sleep
+
+from airflow.exceptions import AirflowException
+from airflow.providers.amazon.aws.hooks.base_aws import AwsBaseHook
+
+
+class ElastiCacheHook(AwsBaseHook):
+    """
+    Interact with AWS ElastiCache
+    """
+
+    # Constants for ElastiCache describe API response keys
+    REPLICATION_GROUPS = 'ReplicationGroups'
+    REPLICATION_GROUP = 'ReplicationGroup'
+    STATUS = 'Status'
+
+    # Constants for ElastiCache replication group status
+    STATUS_CREATING = 'creating'
+    STATUS_AVAILABLE = 'available'
+    STATUS_DELETING = 'deleting'
+    STATUS_CREATE_FAILED = 'create-failed'
+    STATUS_MODIFYING = 'modifying'
+    STATUS_SNAPSHOTTING = 'snapshotting'
+
+    def __init__(
+        self, max_retries=10, exponential_back_off_factor=1, 
initial_poke_interval=60, *args, **kwargs
+    ):
+        """
+        :param max_retries: Max tries for checking availability of and 
deleting replication group
+        :param exponential_back_off_factor: Factor for deciding next sleep time
+        :param initial_poke_interval: Initial sleep time in seconds
+        """
+        self.max_retries = max_retries
+        self.exponential_back_off_factor = exponential_back_off_factor
+        self.initial_poke_interval = initial_poke_interval
+
+        super().__init__(client_type='elasticache', *args, **kwargs)
+
+    def create_replication_group(self, config):
+        """
+        Call ElastiCache API for creating a replication group
+
+        :param config: Python dictionary to use as config for creating 
replication group
+        :return: Response from ElastiCache create replication group API
+        """
+        return self.conn.create_replication_group(**config)
+
+    def delete_replication_group(self, replication_group_id):
+        """
+        Call ElastiCache API for deleting a replication group
+
+        :param replication_group_id: ID of replication group to delete
+        :return: Response from ElastiCache delete replication group API
+        """
+        return 
self.conn.delete_replication_group(ReplicationGroupId=replication_group_id)
+
+    def describe_replication_group(self, replication_group_id):
+        """
+        Call ElastiCache API for describing a replication group
+
+        :param replication_group_id: ID of replication group to describe
+        :return: Response from ElastiCache describe replication group API
+        """
+        return 
self.conn.describe_replication_groups(ReplicationGroupId=replication_group_id)
+
+    def get_replication_group_status(self, replication_group_id):
+        """
+        Get current status of replication group
+
+        :param replication_group_id: ID of replication group to check for 
status
+        :return: Current status of replication group
+        """
+        return 
self.describe_replication_group(replication_group_id)[self.REPLICATION_GROUPS][0][self.STATUS]
+
+    def is_replication_group_available(self, replication_group_id):
+        """
+        Helper for checking if replication group is available or not
+
+        :param replication_group_id: ID of replication group to check for 
availability
+        :return: True if available else False
+        """
+        return self.get_replication_group_status(replication_group_id) == 
self.STATUS_AVAILABLE
+
+    def _has_reached_terminal_state(self, replication_group_id):
+        """
+        Helper for checking if we should stop poking replication group for 
availability or not
+
+        :param replication_group_id: ID of replication group to check
+        :return: Flag to check if availability check should be stopped or not 
and current status
+        """
+        status = 
self.get_replication_group_status(replication_group_id=replication_group_id)
+
+        return status in (
+            self.STATUS_AVAILABLE,
+            self.STATUS_CREATE_FAILED,
+            self.STATUS_DELETING
+        ), status
+
+    def wait_for_availability(
+        self,
+        replication_group_id,
+        initial_sleep_time=None,
+        exponential_back_off_factor=None,
+        max_retries=None
+    ):
+        """
+        Check if replication is available or not by performing a describe over 
it

Review comment:
       This doc talks about replication -- but is it just health of 
elasticache? (Because this still applies when a single node EC is used, right?)

##########
File path: airflow/providers/amazon/aws/hooks/elasticache.py
##########
@@ -0,0 +1,265 @@
+#
+# Licensed to the Apache Software Foundation (ASF) under one
+# or more contributor license agreements.  See the NOTICE file
+# distributed with this work for additional information
+# regarding copyright ownership.  The ASF licenses this file
+# to you 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.
+
+from time import sleep
+
+from airflow.exceptions import AirflowException
+from airflow.providers.amazon.aws.hooks.base_aws import AwsBaseHook
+
+
+class ElastiCacheHook(AwsBaseHook):
+    """
+    Interact with AWS ElastiCache
+    """
+
+    # Constants for ElastiCache describe API response keys
+    REPLICATION_GROUPS = 'ReplicationGroups'
+    REPLICATION_GROUP = 'ReplicationGroup'
+    STATUS = 'Status'
+
+    # Constants for ElastiCache replication group status
+    STATUS_CREATING = 'creating'
+    STATUS_AVAILABLE = 'available'
+    STATUS_DELETING = 'deleting'
+    STATUS_CREATE_FAILED = 'create-failed'
+    STATUS_MODIFYING = 'modifying'
+    STATUS_SNAPSHOTTING = 'snapshotting'
+
+    def __init__(
+        self, max_retries=10, exponential_back_off_factor=1, 
initial_poke_interval=60, *args, **kwargs
+    ):
+        """
+        :param max_retries: Max tries for checking availability of and 
deleting replication group
+        :param exponential_back_off_factor: Factor for deciding next sleep time
+        :param initial_poke_interval: Initial sleep time in seconds
+        """
+        self.max_retries = max_retries
+        self.exponential_back_off_factor = exponential_back_off_factor
+        self.initial_poke_interval = initial_poke_interval
+
+        super().__init__(client_type='elasticache', *args, **kwargs)
+
+    def create_replication_group(self, config):
+        """
+        Call ElastiCache API for creating a replication group
+
+        :param config: Python dictionary to use as config for creating 
replication group
+        :return: Response from ElastiCache create replication group API
+        """
+        return self.conn.create_replication_group(**config)
+
+    def delete_replication_group(self, replication_group_id):
+        """
+        Call ElastiCache API for deleting a replication group
+
+        :param replication_group_id: ID of replication group to delete
+        :return: Response from ElastiCache delete replication group API
+        """
+        return 
self.conn.delete_replication_group(ReplicationGroupId=replication_group_id)
+
+    def describe_replication_group(self, replication_group_id):
+        """
+        Call ElastiCache API for describing a replication group
+
+        :param replication_group_id: ID of replication group to describe
+        :return: Response from ElastiCache describe replication group API
+        """
+        return 
self.conn.describe_replication_groups(ReplicationGroupId=replication_group_id)
+
+    def get_replication_group_status(self, replication_group_id):
+        """
+        Get current status of replication group
+
+        :param replication_group_id: ID of replication group to check for 
status
+        :return: Current status of replication group
+        """
+        return 
self.describe_replication_group(replication_group_id)[self.REPLICATION_GROUPS][0][self.STATUS]
+
+    def is_replication_group_available(self, replication_group_id):
+        """
+        Helper for checking if replication group is available or not
+
+        :param replication_group_id: ID of replication group to check for 
availability
+        :return: True if available else False
+        """
+        return self.get_replication_group_status(replication_group_id) == 
self.STATUS_AVAILABLE
+
+    def _has_reached_terminal_state(self, replication_group_id):
+        """
+        Helper for checking if we should stop poking replication group for 
availability or not
+
+        :param replication_group_id: ID of replication group to check
+        :return: Flag to check if availability check should be stopped or not 
and current status
+        """
+        status = 
self.get_replication_group_status(replication_group_id=replication_group_id)
+
+        return status in (
+            self.STATUS_AVAILABLE,
+            self.STATUS_CREATE_FAILED,
+            self.STATUS_DELETING
+        ), status
+
+    def wait_for_availability(
+        self,
+        replication_group_id,
+        initial_sleep_time=None,
+        exponential_back_off_factor=None,
+        max_retries=None
+    ):
+        """
+        Check if replication is available or not by performing a describe over 
it
+
+        :param max_retries: Max tries for checking availability of replication 
group
+        :param exponential_back_off_factor: Factor for deciding next sleep time
+        :param initial_sleep_time: Initial sleep time in seconds
+        :param replication_group_id: ID of replication group to check for 
availability
+        :return: True if replication is available else False
+        """
+        sleep_time = initial_sleep_time or self.initial_poke_interval
+        exponential_back_off_factor = exponential_back_off_factor or 
self.exponential_back_off_factor
+        max_retries = max_retries or self.max_retries
+        num_retries = 0
+        status = self.STATUS_CREATE_FAILED
+
+        while num_retries < max_retries:
+            stop_poking, status = 
self._has_reached_terminal_state(replication_group_id=replication_group_id)
+
+            self.log.info(
+                'Current status of replication group with ID : %s is %s',
+                replication_group_id,
+                status
+            )
+
+            if stop_poking:
+                break
+
+            num_retries += 1
+
+            self.log.info('Poke retry: %s. Sleep time: %s. Sleeping...', 
num_retries, sleep_time)
+
+            sleep(sleep_time)
+
+            sleep_time = sleep_time * exponential_back_off_factor
+
+        if status != self.STATUS_AVAILABLE:
+            self.log.warning('Replication group is not available. Current 
status : "%s"', status)
+
+            return False
+
+        return True
+
+    def wait_for_deletion(
+        self,
+        replication_group_id,
+        initial_sleep_time=None,
+        exponential_back_off_factor=None,
+        max_retries=None
+    ):
+        """
+        Helper for deleting a replication group ensuring it is either deleted 
or can't be deleted
+
+        :param replication_group_id: ID of replication to delete
+        :param max_retries: Max tries for checking availability of replication 
group
+        :param exponential_back_off_factor: Factor for deciding next sleep time
+        :param initial_sleep_time: Initial sleep time in second
+        :return: Response from ElastiCache delete replication group API and 
flag to identify if deleted or not
+        """
+        deleted = False
+        sleep_time = initial_sleep_time or self.initial_poke_interval
+        exponential_back_off_factor = exponential_back_off_factor or 
self.exponential_back_off_factor
+        max_retries = max_retries or self.max_retries
+        num_retries = 0
+        response = None
+
+        while not deleted and num_retries < max_retries:
+            try:
+                status = 
self.get_replication_group_status(replication_group_id=replication_group_id)
+
+                self.log.info(
+                    'Current status of replication group with ID : %s is %s',
+                    replication_group_id,
+                    status
+                )
+
+                # Can only delete if status is `available`
+                # Status becomes `deleting` after this call so this will only 
run once
+                if status == self.STATUS_AVAILABLE:
+                    response = 
self.delete_replication_group(replication_group_id=replication_group_id)
+
+            except self.conn.exceptions.ReplicationGroupNotFoundFault:
+                self.log.info("Replication group with ID : '%s' does not 
exist", replication_group_id)

Review comment:
       ```suggestion
                   self.log.info("Replication group with ID '%s' does not 
exist", replication_group_id)
   ```

##########
File path: tests/providers/amazon/aws/hooks/test_elasticache.py
##########
@@ -0,0 +1,188 @@
+#
+# Licensed to the Apache Software Foundation (ASF) under one
+# or more contributor license agreements.  See the NOTICE file
+# distributed with this work for additional information
+# regarding copyright ownership.  The ASF licenses this file
+# to you 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.
+
+from unittest import TestCase
+from unittest.mock import Mock
+
+from airflow.exceptions import AirflowException
+
+
+class TestElastiCacheHook(TestCase):
+    """
+    Test ElastiCacheHook
+    """
+    replication_group_id = "test-elasticache-hook"
+
+    replication_group_config = {
+        'ReplicationGroupId': replication_group_id,
+        'ReplicationGroupDescription': replication_group_id,
+        'AutomaticFailoverEnabled': False,
+        'NumCacheClusters': 1,
+        'CacheNodeType': 'cache.m5.large',
+        'Engine': 'redis',
+        'EngineVersion': '5.0.4',
+        'CacheParameterGroupName': 'default.redis5.0'
+    }
+
+    valid_status = ('creating', 'available', 'modifying', 'deleting', 'create 
- failed', 'snapshotting')
+
+    hook = Mock()
+
+    def test_get_conn_not_none(self):
+        """
+        Test connection is not None
+        """
+        self.assertIsNotNone(self.hook.conn)
+
+    def test_create_replication_group(self):
+        """
+        Test creation of replication group
+        """
+        self.hook.create_replication_group.return_value = {
+            "ReplicationGroup": {
+                "ReplicationGroupId": self.replication_group_id,
+                "Status": "creating"
+            }
+        }
+        response = 
self.hook.create_replication_group(config=self.replication_group_config)
+
+        assert response["ReplicationGroup"]["ReplicationGroupId"] == 
self.replication_group_id
+        assert response["ReplicationGroup"]["Status"] == "creating"

Review comment:
       This isn't testing real code here -- you are only calling a mock 
function but not actually calling the real code anywhere from the hook.

##########
File path: airflow/providers/amazon/aws/hooks/elasticache.py
##########
@@ -0,0 +1,265 @@
+#
+# Licensed to the Apache Software Foundation (ASF) under one
+# or more contributor license agreements.  See the NOTICE file
+# distributed with this work for additional information
+# regarding copyright ownership.  The ASF licenses this file
+# to you 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.
+
+from time import sleep
+
+from airflow.exceptions import AirflowException
+from airflow.providers.amazon.aws.hooks.base_aws import AwsBaseHook
+
+
+class ElastiCacheHook(AwsBaseHook):
+    """
+    Interact with AWS ElastiCache
+    """
+
+    # Constants for ElastiCache describe API response keys
+    REPLICATION_GROUPS = 'ReplicationGroups'
+    REPLICATION_GROUP = 'ReplicationGroup'
+    STATUS = 'Status'
+
+    # Constants for ElastiCache replication group status
+    STATUS_CREATING = 'creating'
+    STATUS_AVAILABLE = 'available'
+    STATUS_DELETING = 'deleting'
+    STATUS_CREATE_FAILED = 'create-failed'
+    STATUS_MODIFYING = 'modifying'
+    STATUS_SNAPSHOTTING = 'snapshotting'
+
+    def __init__(
+        self, max_retries=10, exponential_back_off_factor=1, 
initial_poke_interval=60, *args, **kwargs
+    ):
+        """
+        :param max_retries: Max tries for checking availability of and 
deleting replication group
+        :param exponential_back_off_factor: Factor for deciding next sleep time
+        :param initial_poke_interval: Initial sleep time in seconds
+        """
+        self.max_retries = max_retries
+        self.exponential_back_off_factor = exponential_back_off_factor
+        self.initial_poke_interval = initial_poke_interval
+
+        super().__init__(client_type='elasticache', *args, **kwargs)
+
+    def create_replication_group(self, config):
+        """
+        Call ElastiCache API for creating a replication group
+
+        :param config: Python dictionary to use as config for creating 
replication group
+        :return: Response from ElastiCache create replication group API
+        """
+        return self.conn.create_replication_group(**config)
+
+    def delete_replication_group(self, replication_group_id):
+        """
+        Call ElastiCache API for deleting a replication group
+
+        :param replication_group_id: ID of replication group to delete
+        :return: Response from ElastiCache delete replication group API
+        """
+        return 
self.conn.delete_replication_group(ReplicationGroupId=replication_group_id)
+
+    def describe_replication_group(self, replication_group_id):
+        """
+        Call ElastiCache API for describing a replication group
+
+        :param replication_group_id: ID of replication group to describe
+        :return: Response from ElastiCache describe replication group API
+        """
+        return 
self.conn.describe_replication_groups(ReplicationGroupId=replication_group_id)
+
+    def get_replication_group_status(self, replication_group_id):
+        """
+        Get current status of replication group
+
+        :param replication_group_id: ID of replication group to check for 
status
+        :return: Current status of replication group
+        """
+        return 
self.describe_replication_group(replication_group_id)[self.REPLICATION_GROUPS][0][self.STATUS]
+
+    def is_replication_group_available(self, replication_group_id):
+        """
+        Helper for checking if replication group is available or not
+
+        :param replication_group_id: ID of replication group to check for 
availability
+        :return: True if available else False
+        """
+        return self.get_replication_group_status(replication_group_id) == 
self.STATUS_AVAILABLE
+
+    def _has_reached_terminal_state(self, replication_group_id):
+        """
+        Helper for checking if we should stop poking replication group for 
availability or not
+
+        :param replication_group_id: ID of replication group to check
+        :return: Flag to check if availability check should be stopped or not 
and current status
+        """
+        status = 
self.get_replication_group_status(replication_group_id=replication_group_id)
+
+        return status in (
+            self.STATUS_AVAILABLE,
+            self.STATUS_CREATE_FAILED,
+            self.STATUS_DELETING
+        ), status
+
+    def wait_for_availability(
+        self,
+        replication_group_id,
+        initial_sleep_time=None,
+        exponential_back_off_factor=None,
+        max_retries=None
+    ):
+        """
+        Check if replication is available or not by performing a describe over 
it
+
+        :param max_retries: Max tries for checking availability of replication 
group
+        :param exponential_back_off_factor: Factor for deciding next sleep time
+        :param initial_sleep_time: Initial sleep time in seconds
+        :param replication_group_id: ID of replication group to check for 
availability
+        :return: True if replication is available else False
+        """
+        sleep_time = initial_sleep_time or self.initial_poke_interval
+        exponential_back_off_factor = exponential_back_off_factor or 
self.exponential_back_off_factor
+        max_retries = max_retries or self.max_retries
+        num_retries = 0
+        status = self.STATUS_CREATE_FAILED
+
+        while num_retries < max_retries:
+            stop_poking, status = 
self._has_reached_terminal_state(replication_group_id=replication_group_id)
+
+            self.log.info(
+                'Current status of replication group with ID : %s is %s',
+                replication_group_id,
+                status
+            )
+
+            if stop_poking:
+                break
+
+            num_retries += 1
+
+            self.log.info('Poke retry: %s. Sleep time: %s. Sleeping...', 
num_retries, sleep_time)
+
+            sleep(sleep_time)
+
+            sleep_time = sleep_time * exponential_back_off_factor
+
+        if status != self.STATUS_AVAILABLE:
+            self.log.warning('Replication group is not available. Current 
status : "%s"', status)
+
+            return False
+
+        return True
+
+    def wait_for_deletion(
+        self,
+        replication_group_id,
+        initial_sleep_time=None,
+        exponential_back_off_factor=None,
+        max_retries=None
+    ):
+        """
+        Helper for deleting a replication group ensuring it is either deleted 
or can't be deleted
+
+        :param replication_group_id: ID of replication to delete
+        :param max_retries: Max tries for checking availability of replication 
group
+        :param exponential_back_off_factor: Factor for deciding next sleep time
+        :param initial_sleep_time: Initial sleep time in second
+        :return: Response from ElastiCache delete replication group API and 
flag to identify if deleted or not
+        """
+        deleted = False
+        sleep_time = initial_sleep_time or self.initial_poke_interval
+        exponential_back_off_factor = exponential_back_off_factor or 
self.exponential_back_off_factor
+        max_retries = max_retries or self.max_retries
+        num_retries = 0
+        response = None
+
+        while not deleted and num_retries < max_retries:
+            try:
+                status = 
self.get_replication_group_status(replication_group_id=replication_group_id)
+
+                self.log.info(
+                    'Current status of replication group with ID : %s is %s',
+                    replication_group_id,
+                    status
+                )
+
+                # Can only delete if status is `available`
+                # Status becomes `deleting` after this call so this will only 
run once
+                if status == self.STATUS_AVAILABLE:
+                    response = 
self.delete_replication_group(replication_group_id=replication_group_id)
+
+            except self.conn.exceptions.ReplicationGroupNotFoundFault:
+                self.log.info("Replication group with ID : '%s' does not 
exist", replication_group_id)
+
+                deleted = True
+
+            # This should never occur as we only issue a delete request when 
status is `available`
+            # which is a valid status for deletion. Still handling for safety.
+            except self.conn.exceptions.InvalidReplicationGroupStateFault as 
exp:
+                # status      Error Response
+                # creating  - Cache cluster <cluster_id> is not in a valid 
state to be deleted.
+                # deleting  - Replication group <replication_group_id> has 
status deleting which is not valid
+                #             for deletion.
+                # modifying - Replication group <replication_group_id> has 
status deleting which is not valid
+                #             for deletion.
+
+                message = exp.response['Error']['Message']
+
+                self.log.info('Received message : %s', message)

Review comment:
       ```suggestion
                   self.log.error('Received error message from AWS API: %s', 
message)
   ```




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