README.md

Dynamic DynamoDB - lambda

Use DynamoDB autoscaling with lambda!
It's Dynamic DynamoDB's simple lambda version

functional/running test passed. but before use, Test it please

please give me any report/suggestion, Welcome

Feature

• autoscale DynamoDB's provisioned read/write capacity
• run by lambda functon with scheduled event

File Structure

• index.js - main handler & flow source. using async
• tasks.js - Detail work sources. using AWS SDK
• config.js - capacity scaling rule configuration

How to use

1. $ git clone https://github.com/rockeee/dynamic-dynamodb-lambda.git or download zip
2. $ npm install to download npm modules
3. modify config.js for your configuration.

• almost same with Dynamic DynamoDB's option

module.exports = {
 region : 'us-west-2', // region
 timeframeMin : 5, // evaluation timeframe (minute)
 tables :
     [
         {
         tableName : 'testTable',     // table name
         reads_upper_threshold : 90,  // read incrase threshold (%)
         reads_lower_threshold : 30,  // read decrase threshold (%)
         increase_reads_with : 90,    // read incrase amount (%)
         decrease_reads_with : 30,    // read decrase amount (%)
         base_reads : 5,              // minimum read Capacity
         writes_upper_threshold : 90, // write incrase amount (%)
         writes_lower_threshold : 40, // write decrase amount (%)
         increase_writes_with : 90,   // write incrase amount (%)
         decrease_writes_with : 30,   // write incrase amount (%)
         base_writes : 5              // minimum write Capacity
         }
         ,
         {
         tableName : 'testTable2',
         reads_upper_threshold : 90,
         reads_lower_threshold : 30,
         increase_reads_with : 0,     // to don't scale up reads
         decrease_reads_with : 0,     // to don't scale down reads
         base_reads : 3,
         writes_upper_threshold : 90,
         writes_lower_threshold : 40,
         increase_writes_with : 0,    // to don't scale up writes
         decrease_writes_with : 0,    // to don't scale down writes
         base_writes : 3
         }
         // additional table...
     ]
};

4. deploy to lamda function with your favorite method (just zip, or use tool like node-lambda)
5. check lambda function's configuration

• memory - 128MB, timeout - 10sec
• set Cloudwatch Event Rule to run your lambda function. for detail, refer this
• set & attach role to lambda function
• example role policy

 {
 "Version": "2012-10-17",
 "Statement": [
     {
         "Sid": "",
         "Action": [
             "dynamodb:DescribeTable",
             "dynamodb:UpdateTable",
             "CloudWatch:getMetricStatistics"
         ],
         "Effect": "Allow",
         "Resource": "*"
     },
     {
         "Sid": "",
         "Resource": "*",
         "Action": [
             "logs:CreateLogGroup",
             "logs:CreateLogStream",
             "logs:PutLogEvents"
         ],
         "Effect": "Allow"
     }
 ]
}

Roadmap

• more stable
• add SNS noti when scaled/failed