The configuration parameters for the ClickHouse service of an E-MapReduce (EMR) ClickHouse cluster include client parameters, server parameters, user permission parameters, and extended parameters. This topic describes how to configure user permissions for the ClickHouse service.

Background information

The server-users and server-metrika tabs display the parameters that are used to configure user permissions. The parameters are related to users, profiles, and quotas. Configuration details:
Note For more information about the configurations of the ClickHouse client, ClickHouse server, and extended parameters for the ClickHouse service, see Configuration parameters.

Prerequisites

An EMR ClickHouse cluster is created. For more information, see Create a ClickHouse cluster.

Configure the parameters that are related to users

You can view or modify the parameters on the Configure tab of the ClickHouse service page. The parameters that are related to users are displayed on the server-users tab.

Parameter Description
users.default.access_management Specifies whether to grant management permissions to the user named default. Valid values:
  • true: grants management permissions to the user named default. This is the default value.
  • false: does not grant management permissions to the user named default.
users.default.networks.ip The IP address that can be accessed by the user named default. The default value is ::/0, which specifies that all IP addresses can be accessed by the user named default.
If you specify multiple IP addresses, separate the IP addresses with commas (,).
Important You must configure at least one of the users.default.networks.ip, users.default.networks.host, and users.default.networks.host_regexp parameters. Otherwise, the network may be disconnected.
users.default.profile The default name of the profile that is used by the user named default. Default value: default.
users.default.password The password of the user named default on the ClickHouse server.
Important We recommend that you do not use this parameter. We recommend that you add a custom parameter users.default.password_sha256_hex or users.default.password_double_sha1_hex to configure a password.
  • users.default.password_sha256_hex: the hexadecimal string of a key that is generated by using Secure Hash Algorithm (SHA)-256.
  • users.default.password_double_sha1_hex: the hexadecimal string of a key that is generated by using SHA-1 twice.
users.default.quota The default quota that is used by the user named default. Default value: default.

Configure the parameters that are related to profiles

You can view or modify the parameters on the Configure tab of the ClickHouse service page. The parameters that are related to profiles are displayed on the server-users tab.

Parameter Description
profiles.default.max_memory_usage The maximum memory for the profile named default. This parameter specifies the maximum memory that can be used for a single query.

Default value: 0. Unit: bytes.

profiles.default.use_uncompressed_cache Specifies whether to use the cache of uncompressed data blocks for the profile named default. Valid values:
  • 1: uses the cache of uncompressed data blocks.
  • 0: does not use the cache of uncompressed data blocks. This is the default value.
profiles.default.load_balancing The value of load_balancing in the profile named default. Default value: random. This parameter specifies the algorithm of replica selection that is used for distributed query processing.

For more information about the algorithm, see Settings.

profiles.readonly.readonly Specifies whether to allow the profile named readonly to perform the read-only operation. Valid values:
  • 1: allows the profile named readonly to perform the read-only operation. This is the default value.
  • 0: does not allow the profile named readonly to perform the read-only operation.

Configure the parameters that are related to quotas

You can view or modify the parameters on the Configure tab of the ClickHouse service page. The parameters that are related to quotas are displayed on the server-metrika tab.

quotas_default: You can configure multiple quotas to flexibly adjust resource limits. This parameter specifies the value of the default quota of the user. The quota name is specified by the users.default.quota parameter. To add the settings of another quota, click Add Configuration Item on the Configure tab. For more information, see Add configuration items..