ApsaraDB RDS:Configure scheduled tasks to adjust the number of RCUs for a serverless RDS instance

Step 1: Install dependencies

Install Python and install the Alibaba Cloud RDS SDK dependencies, then install APScheduler:

pip install apscheduler

Step 2: Download the SDK sample code

1. Go to the ModifyDBInstanceSpec debugging page in OpenAPI Explorer.

2. On the Parameters tab, set the following values:

   Parameter	Description	Value
   DBInstanceId	Instance ID	rm-bp1t8v93k6e15****
   PayType	Billing method	Serverless
   Direction	Specification change type	Serverless
   MaxCapacity	Maximum number of RCUs	8.0
   MinCapacity	Minimum number of RCUs	0.5
   AutoPause	Enable automatic start and stop	false
   SwitchForce	Enable forced scaling	true

3. On the SDK Sample Code tab, select Python from the Languages dropdown and click Download Project to download the sample package.

   Download the SDK V2.0 sample project.

4. Extract the package on your machine and navigate to the alibabacloud_sample directory.

Step 3: Add scheduled tasks to the sample code

Open sample.py and replace its contents with the following. All examples use a cron trigger via scheduler.add_job(..., 'cron', hour=H, minute=M) to set the execution time.

# -*- coding: utf-8 -*-
import os
import sys
from typing import List, Dict
from alibabacloud_rds20140815.client import Client as Rds20140815Client
from alibabacloud_tea_openapi import models as open_api_models
from alibabacloud_rds20140815 import models as rds_20140815_models
from alibabacloud_tea_util import models as util_models
from alibabacloud_tea_console.client import Client as ConsoleClient
from alibabacloud_tea_util.client import Client as UtilClient
from apscheduler.schedulers.blocking import BlockingScheduler

class Sample:
    def __init__(self):
        pass

    @staticmethod
    def create_client() -> Rds20140815Client:
        """
        Use your AccessKey ID and AccessKey secret to initialize a client.
        @return: Client
        @throws Exception
        """
        # If the project code is leaked, the AccessKey pair may be leaked and the security of resources within your account may be compromised. The following sample code is provided only for reference.
        # For security purposes, we recommend that you use temporary access credentials that are provided by Security Token Service (STS). For more information, see https://www.alibabacloud.com/help/en/sdk/developer-reference/v2-manage-php-access-credentials.
        config = open_api_models.Config(
            # Required. Make sure that the ALIBABA_CLOUD_ACCESS_KEY_ID environment variable is configured. ,
            access_key_id=os.environ['ALIBABA_CLOUD_ACCESS_KEY_ID'],
            # Required. Make sure that the ALIBABA_CLOUD_ACCESS_KEY_SECRET environment variable is configured. ,
            access_key_secret=os.environ['ALIBABA_CLOUD_ACCESS_KEY_SECRET']
        )
        # For endpoint information, see https://api.aliyun.com/product/Rds.
        config.endpoint = f'rds.aliyuncs.com'
        return Rds20140815Client(config)

    @staticmethod
    def modify_db_instance_spec(config: Dict[str, float]) -> None:
        """
        Call ModifyDBInstanceSpec to update the RCU range of the serverless instance.
        """
        client = Sample.create_client()
        serverless_configuration = rds_20140815_models.ModifyDBInstanceSpecRequestServerlessConfiguration(
            max_capacity=config['max_capacity'],
            min_capacity=config['min_capacity'],
            auto_pause=config['auto_pause'],
            switch_force=config['switch_force']
        )
        modify_dbinstance_spec_request = rds_20140815_models.ModifyDBInstanceSpecRequest(
            dbinstance_id='rm-bp1t8v93k6e15****',
            direction='Serverless',
            pay_type='Serverless',
            serverless_configuration=serverless_configuration
        )
        runtime = util_models.RuntimeOptions(
            read_timeout=50000,
            connect_timeout=50000
        )
        try:
            resp = client.modify_dbinstance_spec_with_options(modify_dbinstance_spec_request, runtime)
            ConsoleClient.log(UtilClient.to_jsonstring(resp))
        except Exception as error:
            print(error.message)
            print(error.data.get("Recommend"))
            UtilClient.assert_as_string(error.message)

    @staticmethod
    def main(args: List[str]) -> None:
        scheduler = BlockingScheduler()

        # At 07:50, raise the minimum to 4 RCUs to prepare for the 08:00 peak.
        config_8am = {
            'max_capacity': 8,
            'min_capacity': 4,
            'auto_pause': False,
            'switch_force': True
        }

        # At 09:00, restore the default range of 0.5–8 RCUs.
        config_9am = {
            'max_capacity': 8,
            'min_capacity': 0.5,
            'auto_pause': False,
            'switch_force': True
        }

        # cron trigger: hour=H, minute=M runs the task at H:M every day.
        scheduler.add_job(Sample.modify_db_instance_spec, 'cron', hour=7, minute=50, args=[config_8am])
        scheduler.add_job(Sample.modify_db_instance_spec, 'cron', hour=9, minute=0, args=[config_9am])

        try:
            scheduler.start()
        except (KeyboardInterrupt, SystemExit):
            pass

if __name__ == '__main__':
    Sample.main(sys.argv[1:])

Key parameters:

Step 1: Set up prerequisites

Create a RAM user and grant permissions and configure environment variables.

Step 2: Download the sample package

Download and extract demo.zip to your machine.

Step 3: Configure scheduled tasks in ScheduleTask.java

Open ScheduleTask.java and configure the cron expressions for your schedule. The @Scheduled annotation uses the format "Second Minute Hour Day Month Week". For the full cron expression syntax, see the Spring @Scheduled reference).

The following example sets the RCU range to [4, 8] at 07:50 and restores it to [0.5, 8] at 09:00:

package com.example.demo;

import org.springframework.scheduling.annotation.Scheduled;
import org.springframework.stereotype.Component;

@Component
public class ScheduleTask {

    // At 07:50 every day, raise the minimum to 4 RCUs before the 08:00 peak.
    @Scheduled(cron = "0 50 7 * * ? ")
    public void scheduleTask8am() {
        ModifySpecParams params = new ModifySpecParams();
        params.setRegionId("cn-hangzhou");
        params.setDBInstanceId("rm-bp1t8v93k6e15****");
        params.setDirection("Serverless");
        params.setPayType("Serverless");
        params.setAutoPause(false);
        params.setSwitchForce(true);
        params.setMaxCapacity(8);
        params.setMinCapacity(4);
        ModifyDBInstanceSpec.modify(params);
    }

    // At 09:00 every day, restore the default range of 0.5–8 RCUs.
    @Scheduled(cron = "0 0 9 * * ? ")
    public void scheduleTask9am() {
        ModifySpecParams params = new ModifySpecParams();
        params.setRegionId("cn-hangzhou");
        params.setDBInstanceId("rm-bp1t8v93k6e15****");
        params.setDirection("Serverless");
        params.setPayType("Serverless");
        params.setAutoPause(false);
        params.setSwitchForce(true);
        params.setMaxCapacity(8);
        params.setMinCapacity(0.5);
        ModifyDBInstanceSpec.modify(params);
    }
}

Cron expression quick reference:

Key parameters: