Example Use Case: Creating an Elastic Resource Pool and Running Jobs

This section walks you through the procedure of adding a queue to an elastic resource pool and binding an enhanced datasource connection to the elastic resource pool.

Figure 1 Process of creating an elastic resource pool

**Table 1** Procedure
Step	Description	Reference
Create an elastic resource pool	Create an elastic resource pool and configure basic information, such as the billing mode, CU range, and CIDR block.	Creating an Elastic Resource Pool and Creating Queues Within It
Add a queue to the elastic resource pool	Add the queue where your jobs will run on to the elastic resource pool. The operations are as follows: Set basic information about the queue, such as the name and type. Configure the scaling policy of the queue, including the priority, period, and the maximum and minimum CUs allowed for scaling.	Creating an Elastic Resource Pool and Creating Queues Within It Adjusting Scaling Policies for Queues in an Elastic Resource Pool
(Optional) Create an enhanced datasource connection.	If a job needs to access data from other data sources, for example, GaussDB(DWS) and RDS, you need to create a datasource connection. The created datasource connection must be bound to the elastic resource pool.	Creating an Enhanced Datasource Connection
Run a job.	Create and submit the job as you need.	Managing SQL Jobs Flink Job Overview Creating a Spark Job

Step 1: Create an Elastic Resource Pool

Log in to the DLI management console. In the navigation pane on the left, choose Resources > Resource Pool.
On the displayed page, click Buy Resource Pool in the upper right corner.
On the displayed page, set the following parameters:
- Name: Enter the name of the elastic resource pool. For example, pool_test.
- CU range: Minimum and maximum CUs of the elastic resource pool.
- CIDR Block: Network segment of the elastic resource pool. For example, 172.16.0.0/18.
- Set other parameters as required.
Figure 2 Creating an elastic resource pool

For details about how to create an elastic resource pool, see Creating an Elastic Resource Pool and Creating Queues Within It.
Click Buy. Confirm the configuration and click Pay.
Go to the Resource Pool page to view the creation status. If the status is Available, the elastic resource pool is ready for use.

Step 2: Add a Queue to the Elastic Resource Pool

In the Operation column of the created elastic resource pool, click Add Queue.
Specify the basic information about the queue. The configuration parameters are as follows:
- Name: Queue name
- Type: Queue type In this example, select For general purpose.
  For SQL: The queue is used to run Spark SQL and HetuEngine jobs.
  
  For general purpose: The queue is used to run Flink and Spark Jar jobs.
- Set other parameters as required.
Figure 3 Creating a queue
Click Next. On the displayed page, set Min CU to 64 and Max CU to 64.
Figure 4 Set scaling policy for the queue
Click OK. The queue is added.

(Optional) Step 3: Create an Enhanced Datasource Connection

In this example, a datasource connection is required to connect to RDS. You need to create a datasource connection. If your job does not need to connect to an external data source, skip this step.

Log in to the RDS console and create an RDS DB instance.
For details, see Buying an RDS for MySQL DB Instance.
Click Create Database. In the dialog box that appears, enter database name test2. Then, click OK.
Locate the row that contains the test2 database, click Query SQL Statements in the Operation column. On the displayed page, enter the following statement to create table tabletest2. Click Execute SQL. The table creation statement is as follows:
```
CREATE TABLE `tabletest2` (
	`id` int(11) unsigned,
	`name` VARCHAR(32)
)	ENGINE = InnoDB	DEFAULT CHARACTER SET = utf8mb4;
```
On the RDS console, choose Instances form the navigation pane. Click the name of a created RDS DB instance to view its basic information.
In the Connection Information pane, obtain the floating IP address, database port, VPC, and subnet.
Click the security group name. In the Inbound Rules tab, add a rule to allow access from the CIDR block of the elastic resource pool. For example, if the CIDR block of the elastic resource pool is 172.16.0.0/18 and the database port is 3306, set the rule Priority to 1, Action to Allow, Protocol to TCP and Port to 3306, Type to IPv4, and Source to 172.16.0.0/18.
Click OK. The security group rule is added.
Log in to the DLI management console. In the navigation pane on the left, choose Datasource Connections. On the displayed page, click Create in the Enhanced tab.
In the displayed dialog box, set the following parameters:
- Connection Name: Name of the enhanced datasource connection
- Resource Pool: Select the elastic resource pool created in Step 1: Create an Elastic Resource Pool.
  
  If you cannot decide the elastic resource pool in this step, you can skip this parameter, go to the Enhanced tab, and click More > Bind Resource Pool in the Operation column of the row that contains this datasource connection after it is created.
- VPC: Select the VPC of the RDS DB instance obtained in 5.
- Subnet: Select the subnet of the RDS DB instance obtained in 5.
- Set other parameters as you need.
Click OK. Click the name of the created datasource connection to view its status. You can perform subsequent steps only after the connection status changes to Active.
Click Resources > Queue Management, select the target queue, for example, general_test. In the Operation column, click More and select Test Address Connectivity.
In the displayed dialog box, enter Floating IP address:Database port of the RDS database in the Address box and click Test to check whether the database is reachable.

Step 4: Run a Job

Run a Flink SQL jab on a queue in an elastic resource pool.

On the DLI management console, choose Job Management > Flink Jobs. On the Flink Jobs page, click Create Job.
In the Create Job dialog box, set Type to Flink SQL and Name to testFlinkSqlJob. Click OK.

On the job editing page, set the following parameters:

Figure 5 Creating a Flink SQL job

Queue: Select the general_test queue added to the elastic resource pool in Step 2: Add a Queue to the Elastic Resource Pool.
Save Job Log: Enable this function.
OBS Bucket: Select an OBS bucket for storing job logs and grant access permissions of the OBS bucket as prompted.
Enable Checkpointing: Enable this function.

Enter the SQL statement in the editing pane. The following is an example. Modify the parameters in bold as you need.

CREATE SINK STREAM car_info (id INT, name STRING) WITH (
  type = "rds",
  region = "", /* Change the value to the current region ID. */
   'pwd_auth_name'="xxxxx", // Name of the datasource authentication of the password type created on DLI. If datasource authentication is used, you do not need to set the username and password for the job.
db_url = "mysql://192.168.x.x:3306/test2", /* The format is mysql://floating IP address:port number of the RDS database/database name. */
table_name = "tabletest2" /* Table name in RDS database */
);
INSERT INTO
  car_info
SELECT
  13,
  'abc';

Click Check Semantic and ensure that the SQL statement passes the check. Click Save. Click Start, confirm the job parameters, and click Start Now to execute the job.
Wait until the job is complete. The job status changes to Completed.
Log in to the RDS console, click the name of the RDS DB instance. On the displayed page, click the name of the created database, for example, test2, and click Query SQL Statements in the Operation column of the row that containing the tabletest2 table.
On the displayed page, click Execute SQL. Check whether data has been written into the RDS table.
Figure 6 Query result