Help Center/ MapReduce Service/ User Guide (ME-Abu Dhabi Region)/ Storage-Compute Decoupling Operation Guide/ Configuring a Storage-Compute Decoupled Cluster (AK/SK)
Updated on 2022-02-22 GMT+08:00
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Configuring a Storage-Compute Decoupled Cluster (AK/SK)

In or later, OBS can be interconnected with MRS using obs://. Currently, Hadoop, Hive, Spark, Presto, and Flink are supported. HBase cannot use obs:// to interconnect with OBS.

MRS provides the following configuration modes for accessing OBS. You can select one of them. The agency mode is recommended.

  • Bind an agency of the ECS type to an MRS cluster to access OBS, preventing the AK/SK from being exposed in the configuration file. For details, see Configuring a Storage-Compute Decoupled Cluster (Agency).
  • Configure the AK/SK in an MRS cluster. The AK/SK will be exposed in the configuration file in plaintext. Exercise caution when performing this operation. For details, see the following part in this section.

To improve data write performance, change the value of the fs.obs.buffer.dir parameter of the corresponding service to a data disk directory.

Using Hadoop to Access OBS

  • Add the following content to file core-site.xml in the HDFS directory ($client_home/ HDFS/hadoop/etc/hadoop) on the MRS client: 
    <property>
    <name> fs.obs.access.key</name>
    <value>ak</value>
</property>
<property>
    <name> fs.obs.secret.key</name>
    <value>sk</value>
</property>
<property>
    <name> fs.obs.endpoint</name>
    <value>obs endpoint</value>
</property>

    AK and SK will be displayed as plaintext in the configuration file. Exercise caution when setting AK and SK in the file.

    After the configuration is added, you can directly access data on OBS without manually adding the AK/SK and endpoint. For example, run the following command to view the file list of the test_obs_orc directory in the obs-test file system:

    hadoop fs -ls "obs://obs-test/test_obs_orc"

  • Add AK/SK and endpoint to the command line to access data on OBS.

    hadoop fs -Dfs.obs.endpoint=xxx -Dfs.obs.access.key=xx -Dfs.obs.secret.key=xx -ls "obs://obs-test/ test_obs_orc"

Using Hive to Access OBS

  1. Log in to the service configuration page.

    • For versions earlier than MRS 3.x, log in to the cluster details page and choose Components > Hive > Service Configuration.
    • For MRS 3.x or later, log in to FusionInsight Manager. For details, see Accessing FusionInsight Manager (MRS 3.x or Later). Choose Cluster > Services > Hive > Configurations.

  2. In the configuration type drop-down box, switch Basic Configurations to All Configurations.
  3. Search for fs.obs.access.key and fs.obs.secret.key and set them to the AK and SK of OBS respectively.

    If the preceding two parameters cannot be found in the current cluster, choose Hive > Customization in the navigation tree on the left and add the two parameters to the customized parameter core.site.customized.configs.

  4. Click Save Configuration and select Restart the affected services or instances. to restart the Hive service.
  5. Access the OBS directory in the beeline. For example, run the following command to create a Hive table and specify that data is stored in the test_obs directory in the test-bucket file system:

    create table test_obs(a int, b string) row format delimited fields terminated by "," stored as textfile location "obs://test-bucket/test_obs";

Using Spark to Access OBS

SparkSQL depends on Hive. Therefore, when configuring OBS on Spark, you need to modify the OBS configuration used in Using Hive to Access OBS.

  • spark-beeline and spark-sql

    You can add the following OBS attributes to the shell to access OBS:

    set fs.obs.endpoint=xxx
set fs.obs.access.key=xxx
set fs.obs.secret.key=xxx
  • spark-beeline
    The spark-beeline can access OBS by configuring service parameters on Manager. The procedure is as follows:
    1. Log in to the service configuration page.
      • For versions earlier than MRS 3.x, log in to the cluster details page and choose Components > Spark > Service Configuration.
      • For MRS 3.x or later, log in to FusionInsight Manager. For details, see Accessing FusionInsight Manager (MRS 3.x or Later). Choose Cluster > Services > Spark2x > Configurations.
    2. In the configuration type drop-down box, switch Basic Configurations to All Configurations.
    3. Choose JDBCServer > OBS, and set values for fs.obs.access.key and fs.obs.secret.key.

      If the preceding two parameters cannot be found in the current cluster, choose JDBCServer > Customization in the navigation tree on the left and add the two parameters to the customized parameter spark.core-site.customized.configs.

      Figure 1 Parameters for adding an OBS
    4. Click Save Configuration and select Restart the affected services or instances. to restart the HBase service.
    5. Access OBS in spark-beeline. For example, access the obs://obs-demo-input/table/ directory.

      create table test(id int) location 'obs://obs-demo-input/table/';

  • spark-sql and spark-submit

    The spark-sql can also access OBS by modifying the core-site.xml configuration file.

    The method of modifying the configuration file is the same when you use the spark-sql and spark-submit to submit a task to access OBS.

    Add the following content to core-site.xml in the Spark configuration folder ($client_home/Spark/spark/conf) on the MRS client:

    <property>
    <name> fs.obs.access.key</name>
    <value>ak</value>
</property>
<property>
    <name> fs.obs.secret.key</name>
    <value>sk</value>
</property>
<property>
    <name> fs.obs.endpoint</name>
    <value>obs endpoint</value>
</property>

Using Presto to Access OBS

  1. Go to the cluster details page and choose Components > Presto > Service Configuration.
  2. In the configuration type drop-down box, switch Basic Configurations to All Configurations.
  3. Search for and configure the following parameters:

    • Set fs.obs.access.key to AK.
    • Set fs.obs.secret.key to SK.

    If the preceding two parameters cannot be found in the current cluster, choose Presto > Hive in the navigation tree on the left and add the two parameters to the customized parameter core.site.customized.configs.

  4. Click Save Configuration and select Restart the affected services or instances. to restart the Presto service.
  5. Choose Components > Hive > Service Configuration.
  6. In the configuration type drop-down box, switch Basic Configurations to All Configurations.
  7. Search for and configure the following parameters:

    • Set fs.obs.access.key to AK.
    • Set fs.obs.secret.key to SK.

  8. Click Save Configuration and select Restart the affected services or instances. to restart the Hive service.
  9. On the Presto client, run the following statement to create a schema and set location to an OBS path:

    CREATE SCHEMA hive.demo WITH (location = 'obs://obs-demo/presto-demo/');

  10. Create a table in the schema. The table data is stored in the OBS file system. The following is an example.

    CREATE TABLE hive.demo.demo_table WITH (format = 'ORC') AS SELECT * FROM tpch.sf1.customer;

Using Flink to Access OBS

Add the following configuration to the Flink configuration file of the MRS client in Client installation path/Flink/flink/conf/flink-conf.yaml: 
fs.obs.access.key:ak
fs.obs.secret.key: sk  
fs.obs.endpoint: obs endpoint

AK and SK will be displayed as plaintext in the configuration file. Exercise caution when setting AK and SK in the file.

After the configuration is added, you can directly access data on OBS without manually adding the AK/SK and endpoint.