autoscale.py

# update-dynamo-autoscale-settings
import os
import sys
import boto3
from botocore.exceptions import ClientError
# Add path for additional imports
sys.path.append('./lib/python3.7/site-packages')
# Initialize boto3 clients
dynamodb = boto3.resource('dynamodb')
dynamodb_scaling = boto3.client('application-autoscaling')
# Initialize variables
table_name = "your dynamo table name"
table = dynamodb.Table(table_name)
def update_auto_scale_settings(min_write_capacity: int, table_name: str): 
    max_write_capacity = 40000 #default number
    dynamodb_scaling.register_scalable_target(ServiceNamespace = "dynamodb",
                                                 ResourceId = "table/{}".format(table_name),
                                                 ScalableDimension = "dynamodb:table:WriteCapacityUnits",
                                                 MinCapacity = min_write_capacity,
                                                 MaxCapacity = max_write_capacity)
    
    # if you have indexes on the table, add their names to indexes list below
    # indexes = ["index1", "index2", "index3"]
    # for index_name in indexes:
    #     scaling_dynamodb.register_scalable_target(ServiceNamespace = "dynamodb",
    #                                              ResourceId = "table/{table_name}/index/{index_name}".format(table_name = table_name, index_name = index_name),
    #                                              ScalableDimension = "dynamodb:index:WriteCapacityUnits",
    #                                              MinCapacity = min_write_capacity,
    #                                              MaxCapacity = max_write_capacity)
#put_scaling policy is another call that needs to be made, if you want a different target utilization value.
def lambda_handler(event, context):
    
    try:
# logic before updating
write_units = #number
        update_auto_scale_settings(table_name,write_units)
                
        # logic after updating
# Insert item into dynamo
        # table.put_item(Item = record)
                    
    except Exception as e:
        raise e
    
    else:
        print("success")