Configure Tablestore as the metadata backend (SmartData 2.6.0-2.7.2) - E-MapReduce

The JindoFS Namespace Service supports various storage backends. This topic explains how to configure Tablestore as the storage backend.

Prerequisites

You have created an EMR cluster.

For more information, see Create a cluster.
You have created a Tablestore instance. A high-performance instance is recommended.

For more information, see Activate Tablestore and create an instance.

Note
The transaction feature must be enabled.

Background information

When you use Tablestore as the backend for the JindoFS Namespace Service, JindoFS automatically creates a dedicated table within your Tablestore instance for each namespace to store its metadata.

The following figure shows the architecture for the Namespace Service in high availability (HA) mode.

Configure Tablestore

Bind your Tablestore instance to the JindoFS Namespace Service.

Go to the SmartData service.
1. Log on to the EMR console.
2. In the top navigation bar, select a region and a resource group as needed.
3. Click the Clusters tab.
4. On the Clusters page, find your cluster and click Details in the Actions column.
5. In the navigation pane on the left, choose Services > SmartData.
Go to the bigboot service configuration page.
1. Click the Configure tab.
2. Click bigboot .

Configure the following parameters.

For example, assume that you have created a Tablestore instance named emr-jfs in the China (Hangzhou) region and the EMR cluster uses a VPC network. The AccessKey ID for Tablestore is kkkkkk and the AccessKey secret is XXXXXX.

Parameter	Description	Required	Example
namespace.backend.type	Specifies the storage backend type for the Namespace Service. Valid values: `rocksdb` `ots` `raft` Default value: `rocksdb`.	Yes	`ots`
namespace.ots.instance	The name of the Tablestore instance.	Yes	emr-jfs
namespace.ots.accessKey	The AccessKey ID for the Tablestore instance.	No	kkkkkk
namespace.ots.accessSecret	The AccessKey secret for the Tablestore instance.	No	XXXXXX
namespace.ots.endpoint	The endpoint of the Tablestore instance. For standard EMR clusters, we recommend using a VPC endpoint.	Yes	http://emr-jfs.cn-hangzhou.vpc.tablestore.aliyuncs.com

Save the configuration.
1. In the upper-right corner, click Save.
2. In the Confirm dialog box, enter a reason for the change and turn on Auto-update Configuration.
3. Click OK.
In the upper-right corner, click Actions > Restart Jindo Namespace Service.

Configure Tablestore (HA mode)

For EMR clusters in high availability (HA) mode, you can also enable high availability for the Namespace Service.

The HA mode for the Namespace Service uses an active-standby architecture that supports automatic failover. If the active node fails, clients automatically fail over to the new active node. OTS

In the bigboot service configuration of SmartData, configure the following parameters.
1. Change the value of jfs.namespace.server.rpc-address to emr-header-1:8101,emr-header-2:8101.
2. In the upper-right corner, click Custom Configuration, add the namespace.backend.ots.ha parameter, and set its value to true.
3. Click OK.
4. Save the configuration.
  1. In the upper-right corner, click Save.
  2. In the Confirm dialog box, enter a reason for the change and turn on Auto-update Configuration.
  3. Click OK.
In the upper-right corner, click Actions > Restart Jindo Namespace Service.
In the upper-right corner, click Actions > Restart Jindo Storage Service.