Running a SparkSql Job¶
You can submit programs developed by yourself to MRS to execute them, and obtain the results. This section describes how to submit a SparkSQL job on the MRS console. SparkSQL jobs are used for data query and analysis. Both SQL statements and scripts are supported. If SQL statements contain sensitive information, use Spark Script to submit them.
Prerequisites¶
You have uploaded the program packages and data files required for running jobs to OBS or HDFS.
Submitting a Job on the GUI¶
Log in to the MRS console.
Choose Clusters > Active Clusters, select a running cluster, and click its name to switch to the cluster details page.
If Kerberos authentication is enabled for the cluster, perform the following steps. If Kerberos authentication is not enabled for the cluster, skip this step.
In the Basic Information area on the Dashboard page, click Synchronize on the right side of IAM User Sync to synchronize IAM users. For details, see Synchronizing IAM Users to MRS.
Note
In MRS 1.7.2 or earlier, the job management function is unavailable in a cluster with Kerberos authentication enabled. You need to submit a job in the background.
When the policy of the user group to which the IAM user belongs changes from MRS ReadOnlyAccess to MRS CommonOperations, MRS FullAccess, or MRS Administrator, wait for 5 minutes until the new policy takes effect after the synchronization is complete because the SSSD (System Security Services Daemon) cache of cluster nodes needs time to be updated. Then, submit a job. Otherwise, the job may fail to be submitted.
When the policy of the user group to which the IAM user belongs changes from MRS CommonOperations, MRS FullAccess, or MRS Administrator to MRS ReadOnlyAccess, wait for 5 minutes until the new policy takes effect after the synchronization is complete because the SSSD cache of cluster nodes needs time to be updated.
Click the Jobs tab.
For clusters of MRS 1.9.2 or later: Click Create. On the displayed Create Job page, set Type to SparkSql and configure SparkSql job information by referring to Table 1.
Table 1 Job configuration information¶ Parameter
Description
Name
Job name. It contains 1 to 64 characters. Only letters, digits, hyphens (-), and underscores (_) are allowed.
Note
You are advised to set different names for different jobs.
SQL Type
Submission type of the SQL statement
SQL
Script
SQL Statement
This parameter is valid only when SQL Type is set to SQL. Enter the SQL statement to be executed, and then click Check to check whether the SQL statement is correct. If you want to submit and execute multiple statements at the same time, use semicolons (;) to separate them.
SQL File
This parameter is valid only when SQL Type is set to Script. The path of the SQL file to be executed must meet the following requirements:
Contains a maximum of 1,023 characters, excluding special characters such as
;|&><'$.The parameter value cannot be empty or full of spaces.The path of the program to be executed can be stored in HDFS or OBS. The path varies depending on the file system.
OBS: The path must start with obs://. Example: obs://wordcount/program/xxx.jar
HDFS: The path must start with /user. For details about how to import data to HDFS, see Importing Data.
For SparkScript and HiveScript, the path must end with .sql. For MapReduce, the path must end with .jar. For Flink and SparkSubmit, the path must end with .jar or .py. The .sql, .jar, and .py are case-insensitive.
Note
For clusters of MRS 1.9.2or later: A file path on OBS can start with obs://. To submit jobs in this format, you need to configure permissions for accessing OBS.
If the OBS permission control function is enabled during cluster creation, you can use the obs:// directory without extra configuration.
If the OBS permission control function is not enabled or is not supported when you create a cluster, configure the function by following instructions in Accessing OBS.
Program Parameter
(Optional) Used to configure optimization parameters such as threads, memory, and vCPUs for the job to optimize resource usage and improve job execution performance.
Table 2 describes the common parameters of a running program.
Service Parameter
(Optional) It is used to modify service parameters for the job. The parameter modification applies only to the current job. To make the modification take effect permanently for the cluster, follow instructions in Configuring Service Parameters.
To add multiple parameters, click
on the right. To delete a parameter, click Delete on the right.Table 3 lists the common service configuration parameters.
Command Reference
Command submitted to the background for execution when a job is submitted.
Table 2 Program parameters¶ Parameter
Description
Example Value
--conf
Task configuration items to be added.
spark.executor.memory=2G
--driver-memory
Running memory of a driver.
2G
--num-executors
Number of executors to be started.
5
--executor-cores
Number of executor cores.
2
--jars
Additional dependency packages of a task, which is used to add the external dependency packages to the task.
---executor-memory
Executor memory.
2G
Table 3 Service parameters¶ Parameter
Description
Example Value
fs.obs.access.key
Key ID for accessing OBS.
-fs.obs.secret.key
Key corresponding to the key ID for accessing OBS.
-For clusters of MRS 1.9.2 or earlier: Perform the following operations to create SparkScript and Spark SQL jobs.
SparkScript job: On the Jobs tab page, click Create. On the displayed Create Job page, set Type to SparkScript and configure job information by referring to Table 4.
Spark SQL job: Click the Spark SQL tab, add SQL statements, and submit the SQL statements after a check.
Table 4 Job configuration information¶ Parameter
Description
Name
Job name. It contains 1 to 64 characters. Only letters, digits, hyphens (-), and underscores (_) are allowed.
Note
You are advised to set different names for different jobs.
Program Path
Path of the program package to be executed. The following requirements must be met:
Contains a maximum of 1,023 characters, excluding special characters such as
;|&><'$.The parameter value cannot be empty or full of spaces.The path of the program to be executed can be stored in HDFS or OBS. The path varies depending on the file system.
OBS: The path must start with s3a://. Example: s3a://wordcount/program/xxx.jar
HDFS: The path must start with /user. For details about how to import data to HDFS, see Importing Data.
For SparkScript, the path must end with .sql. For MapReduce and Spark, the path must end with .jar. The .sql and .jar are case-insensitive.
Parameters
Key parameter for program execution. The parameter is specified by the function of the user's program. MRS is only responsible for loading the parameter. Multiple parameters are separated by space.
Configuration method: Package name.Class name
The parameter contains a maximum of 150,000 characters. It cannot contain special characters
;|&><'$,but can be left blank.Note
When entering a parameter containing sensitive information (for example, login password), you can add an at sign (@) before the parameter name to encrypt the parameter value. This prevents the sensitive information from being persisted in plaintext. When you view job information on the MRS console, the sensitive information is displayed as *.
Example: username=admin @password=admin_123
Import From
Path for inputting data
Data can be stored in HDFS or OBS. The path varies depending on the file system.
OBS: The path must start with s3a://.
HDFS: The path must start with /user. For details about how to import data to HDFS, see Importing Data.
The parameter contains a maximum of 1,023 characters, excluding special characters such as
;|&>,<'$,and can be left blank.Export To
Path for outputting data
Note
When setting this parameter, select OBS or HDFS. Select a file directory or manually enter a file directory, and click OK.
If you add the hadoop-mapreduce-examples-x.x.x.jar sample program or a program similar to hadoop-mapreduce-examples-x.x.x.jar, enter a directory that does not exist.
Data can be stored in HDFS or OBS. The path varies depending on the file system.
OBS: The path must start with s3a://.
HDFS: The path must start with /user.
The parameter contains a maximum of 1,023 characters, excluding special characters such as
;|&>,<'$,and can be left blank.Log Path
Path for storing job logs that record job running status.
Data can be stored in HDFS or OBS. The path varies depending on the file system.
OBS: The path must start with s3a://.
HDFS: The path must start with /user.
The parameter contains a maximum of 1,023 characters, excluding special characters such as
;|&>,<'$,and can be left blank.
Confirm job configuration information and click OK.
After the job is created, you can manage it.
Submitting a Job in the Background¶
In MRS 3.x and later versions, the default installation path of the client is /opt/Bigdata/client. In MRS 3.x and earlier versions, the default installation path is /opt/client. For details, see the actual situation.
Create a user for submitting jobs. For details, see Creating a User.
In this example, a machine-machine user used in the user development scenario has been created, and user groups (hadoop and supergroup), the primary group (supergroup), and role permissions (System_administrator and default) have been correctly assigned to the user.
Download the authentication credential.
For clusters of MRS 3.x or later, log in to MRS Manager and choose System > Permission > User. In the Operation column of the newly created user, choose More > Download Authentication Credential.
For clusters whose version is earlier than MRS 3.x, log in to MRS Manager and choose System > Manage User. In the Operation column of the newly created user, choose More > Download Authentication Credential.
Log in to the node where the Spark client is located, upload the user authentication credential created in 2 to the /opt directory of the cluster, and run the following command to decompress the package:
tar -xvf MRSTest _xxxxxx_keytab.tar
After the decompression, you obtain the user.keytab and krb5.conf files.
Before performing operations on the cluster, run the following commands:
source /opt/Bigdata/client/bigdata_env
cd $SPARK_HOME
Open the spark-sql CLI and run the following SQL statement:
./bin/spark-sql --conf spark.yarn.principal=MRSTest --conf spark.yarn.keytab=/opt/user.keytab
To execute the SQL file, you need to upload the SQL file (for example, to the /opt/ directory). After the file is uploaded, run the following command:
./bin/spark-sql --conf spark.yarn.principal=MRSTest --conf spark.yarn.keytab=/opt/user.keytab -f /opt/script.sql