Resource Pooling Parameters

ss_enable_dss

Parameter Description: Whether to enable the DSS mode, specified by the user during installation and deployment.

This parameter is of the POSTMASTER type. The database cannot start normally after modification; please do not change it.

Value Range: Boolean, on, off. on indicates that the current installation and deployment enable DSS mode, off indicates that it is not enabled.

Default Value: off

Note:

• The ss_enable_dss parameter defaults to off in single node.
• To enable resource pooling mode, this parameter needs to be set to on.
• After OM automatically installs resource pooling mode, this parameter defaults to on.

ss_enable_dms

Parameter Description: Whether to enable the DMS feature, specified by the user during installation and deployment.

This parameter is of the POSTMASTER type. The database cannot start normally after modification; please do not change it.

Value Range: Boolean, on, off. on indicates that the current installation and deployment enable DMS functionality, off indicates that it is not enabled.

Default Value: off

Note:

• The ss_enable_dms parameter defaults to off in single node.
• To enable resource pooling mode, this parameter needs to be set to on.
• After OM automatically installs resource pooling mode, this parameter defaults to on.

ss_enable_ssl

Parameter Description: Whether to enable the SSL.

This parameter is a POSTMASTER parameter. Set it based on instructions provided in Table 1 GUC parameters.

Value Range: Boolean, on, off. on indicates that SSL is enabled, off indicates that it is not enabled.

Default Value: on

Note:

• The prerequisite for this parameter to take effect is that MogDB's SSL parameter is set to on (master switch).
• Manual modification of this parameter requires changes and restarts on all nodes to take effect; modifying and restarting a single node will result in a timeout failure.
• If this parameter is turned off, the primary and standby machines will not use SSL connections, which poses a risk of impersonation attacks and information leakage.

ss_enable_catalog_centralized

Parameter Description: Resource directory storage mode, not allowed to be modified.

This parameter is a POSTMASTER parameter. Set it based on instructions provided in Table 1 GUC parameters. This parameter is not allowed to be modified

Value Range: Boolean, on, off. on indicates that DRC resources are only stored on the primary node, off indicates that resources are distributed, meaning each node needs to store a portion of DRC resources according to certain rules.

Default Value: on

Note: The ss_enable_catalog_centralized currently does not support modification and only supports using the default value.

ss_instance_id

Parameter Description: Resource pooling instance ID, generated based on the DN specified by the user during installation, this parameter cannot be modified.

This parameter is a POSTMASTER parameter. Set it based on instructions provided in Table 1 GUC parameters.

Default Value: Integer. Value range 0~63.

ss_dss_vg_name

Parameter Description: The volume group name specified by the user during installation, this parameter cannot be modified.

This parameter is a POSTMASTER parameter. Set it based on instructions provided in Table 1 GUC parameters.

Value Range: String

Default Value: The user-defined data volume group name during installation.

ss_dss_conn_path

Parameter Description: The socket file path used by the DSS instance process, this parameter cannot be modified.

This parameter is a POSTMASTER parameter. Set it based on instructions provided in Table 1 GUC parameters.

Value Range: String

Default Value: “ UDS:${DSS_HOME}/.dss_unix_d_socket”, DSS_HOME is user-defined during installation.

ss_interconnect_channel_count

Parameter Description: The number of MES communication channel connections.

This parameter is a POSTMASTER parameter. Set it based on instructions provided in Table 1 GUC parameters.

Value Range: Integer, 1~32

Default Value: 16

ss_work_thread_count

Parameter Description: The number of MES working threads.

This parameter is a POSTMASTER parameter. Set it based on instructions provided in Table 1 GUC parameters.

Value Range: Integer, 16~128

Default Value: 32

ss_recv_msg_pool_size

Parameter Description: The size of the MES message reception pool.

This parameter is a POSTMASTER parameter. Set it based on instructions provided in Table 1 GUC parameters.

Value Range: Integer, 1MB~1024MB, unit: MB

Default Value: 16MB

ss_interconnect_type

Parameter Description: The type of MES communication protocol.

This parameter is a POSTMASTER parameter. Set it based on instructions provided in Table 1 GUC parameters.

Value Range: String type, TCP, RDMA

Default Value: TCP

Note: RDMA communication relies on CX5 network cards and depends on the OCK RDMA dynamic library. Ensure it is correctly configured before enabling.

ss_interconnect_url

Parameter Description: The URL for MES communication between nodes.

This parameter is a POSTMASTER parameter. Set it based on instructions provided in Table 1 GUC parameters.

Value Range: String, format: "node id:ip:port, node id:ip:port, ……."

Default Value: User-defined during installation.

ss_rdma_work_config

Parameter Description: RDMA user-space poll start and end CPU.

This parameter is a POSTMASTER parameter. Set it based on instructions provided in Table 1 GUC parameters.

Value Range: String, "start cpu end cpu" (space-separated), e.g., "10 15"

Default Value: ""

ss_ock_log_path

Parameter Description: The path of the OCK RDMA log file.

This parameter is a POSTMASTER parameter. Set it based on instructions provided in Table 1 GUC parameters.

Value Range: String

Default Value: ""

ss_enable_scrlock

Parameter Description: Whether to use scrlock.

This parameter is a POSTMASTER parameter. Set it based on instructions provided in Table 1 GUC parameters.

Value Range: Boolean, on, off. on indicates to enable the use of scrlock, off indicates not to enable.

Default Value: off

Note: Scrlock requires the use of CX5 network cards and depends on the OCK RDMA dynamic library. Ensure it is correctly configured before enabling.

ss_enable_scrlock_sleep_mode

Parameter Description: Whether to enable scrlock's sleep mode.

This parameter is a POSTMASTER parameter. Set it based on instructions provided in Table 1 GUC parameters.

Value Range: Boolean, on, off. on indicates to enable the use of scrlock's sleep mode, off indicates not to enable.

Default Value: on

Note: Scrlock sleep mode will reduce the CPU occupancy of scrlock but will increase the latency of scrlock.

ss_scrlock_server_port

Parameter Description: The listening port number of the scrlock server.

This parameter is a POSTMASTER parameter. Set it based on instructions provided in Table 1 GUC parameters.

Value Range: Integer, 0~65535

Default Value: 8000

ss_scrlock_worker_count

Parameter Description: The number of scrlock client workers.

This parameter is a POSTMASTER parameter. Set it based on instructions provided in Table 1 GUC parameters.

Value Range: Integer, 2~16

Default Value: 2

ss_scrlock_worker_bind_core

Parameter Description: Scrlock worker start and end CPU.

This parameter is a POSTMASTER parameter. Set it based on instructions provided in Table 1 GUC parameters.

Value Range: String, "start cpu end cpu" (space-separated), e.g., "10 15"

Default Value: ""

Note:

• This parameter can be left blank, in which case scrlock workers are not bound to a CPU.
• The number of start and end CPUs indicated by this parameter must be no less than 2.

ss_scrlock_server_bind_core

Parameter Description: Scrlock server start and end CPU.

This parameter is a POSTMASTER parameter. Set it based on instructions provided in Table 1 GUC parameters.

Value Range: String, "start cpu end cpu" (space-separated), e.g., "10 15"

Default Value: ""

Note: When this parameter is empty, it is equivalent to "0 0", meaning the scrlock server occupies CPU 0.

ss_log_level

Parameter Description: The log level for resource pooling.

This parameter is a SIGHUP parameter. Set it based on instructions provided in Table 1 GUC parameters.

The value 7 represents run logs, and 255 represents both debug logs and run logs being enabled.

Value Range: Integer, 0~887.

Default Value: 7

Note: In high-concurrency scenarios, it is not recommended to configure debug logs. If debug logs are configured, and other parameters use default values, message threads may frequently print logs. In such scenarios, there might be message thread busy handling CM query node status requests, which could lead to a timeout and thus display the standby node status as not normal.

ss_log_backup_file_count

Parameter Description: The number of backup log files.

This parameter is a SIGHUP parameter. Set it based on instructions provided in Table 1 GUC parameters.

Value Range: Integer, 0~1024.

Default Value: 10

ss_log_max_file_size

Parameter Description: The maximum size of the log files.

This parameter is a SIGHUP parameter. Set it based on instructions provided in Table 1 GUC parameters.

Value Range: Integer, 1024~4194304, units in kB.

Default Value: 10MB (i.e., 10240 kB)

ss_enable_aio

Parameter Description: Whether to enable the DSS asynchronous IO function to improve the speed at which dirty pages are flushed to disk under resource pooling.

This parameter is a POSTMASTER parameter. Set it based on instructions provided in Table 1 GUC parameters.

Value Range: Boolean, on, off. on to enable, off to disable.

Default Value: on