Updating the MRS Data Source Configuration¶
Scenario¶
For MRS, if the following parameter configurations of the HDFS cluster change, data may fail to be imported to the data warehouse cluster from the HDFS cluster. Before importing data using the HDFS cluster, you must update the MRS data source configuration.
Prerequisites¶
You have created an MRS data source connection for the data warehouse cluster.
Impact on the System¶
When you are updating an MRS data source connection, the data warehouse cluster will automatically restart and cannot provide services.
Procedure¶
On the GaussDB(DWS) console, choose Clusters > Dedicated Clusters.
In the cluster list, click the name of a cluster. On the page that is displayed, click MRS Data Sources.
In the MRS data source list, select the MRS data source that you want to update. In the Operation column, click Update Configurations.
MRS Cluster Status and Configuration Status of the current connection will be updated. During configuration update, you cannot create a connection. The system checks whether the security group rule is correct. If the rule is incorrect, the system rectifies the fault. The following table describes the parameters.
Table 1 Parameter description¶ Parameter
Description
dfs.client.read.shortcircuit
Specifies whether to enable the local read function.
dfs.client.read.shortcircuit.skip.checksum
Specifies whether to skip data verification during the local read.
dfs.client.block.write.replace-datanode-on-failure.enable
Specifies whether to replace the location storing copies with the new node when data blocks fail to be written to HDFS.
dfs.encrypt.data.transfer
Specifies whether to enable data encryption. The value true indicates that the channels are encrypted. The channels are not encrypted by default.
Note
This parameter is available only for clusters with Kerberos authentication enabled.
This parameter is valid only when hadoop.rpc.protection is set to privacy.
dfs.encrypt.data.transfer.algorithm
Specifies the encryption and decryption algorithm for key transmission.
This parameter is valid only when dfs.encrypt.data.transfer is set to true.
The default value is 3des, indicating that the 3DES algorithm is used for encryption.
dfs.encrypt.data.transfer.cipher.suites
Specifies the encryption and decryption algorithm for the transmission of actually stored data.
If this parameter is not specified, the cryptographic algorithm specified by dfs.encrypt.data.transfer.algorithm is used for data encryption. The default value is AES/CTR/NoPadding.
dfs.replication
Specifies the default number of data copies.
dfs.blocksiz
Specifies the default size of a data block.
hadoop.security.authentication
Specifies the security authentication mode.
hadoop.rpc.protection
Specifies the RPC communication protection mode.
Default value:
Security mode (Kerberos authentication enabled): privacy
Common mode (Kerberos authentication disabled): authentication
Note
authentication: indicates that only authentication is required.
integrity: indicates that authentication and consistency check need to be performed.
privacy: indicates that authentication, consistency check, and encryption need to be performed.
dfs.domain.socket.path
Specifies the locally used Domain socket path.