GTM Parameters

nodename

Parameter description: Specifies the name of the primary or standby GTM.

Parameter type: string.

Unit: none

Value range: a string, which complies with the identifier naming convention

Default value: ""

Setting method: This is a POSTMASTER parameter. Set it based on instructions provided in Table 1.

Setting suggestion: Retain the default value.

Risks and impacts of improper settings: Change the parameter value after fully understanding the parameter meaning and verifying it through testing.

port

Parameter description: Specifies the host port number listened by the primary or standby GTM.

Parameter type: integer.

Unit: none

Value range: 0 to 2147483647. The recommended value range is 1024 to 65535.

Default value: 6666

Setting method: This is a POSTMASTER parameter. Set it based on instructions provided in Table 1.

Setting suggestion: Retain the default value.

Risks and impacts of improper settings: Change the parameter value after fully understanding the parameter meaning and verifying it through testing.

log_file

Parameter description: Specifies a log file name.

Parameter type: string.

Unit: none

Value range: a string, which complies with the identifier naming convention

Default value: "gtm-%Y-%m-%d_%H%M%S.log"

Setting method: This is a SIGHUP parameter. Set it based on instructions provided in Table 1.

Setting suggestion: Retain the default value.

Risks and impacts of improper settings: Change the parameter value after fully understanding the parameter meaning and verifying it through testing.

active_host

Parameter description: Specifies the IP address of a target GTM. For the primary GTM, it is the IP address of the standby GTM; for the standby GTM, it is the IP address of the primary GTM. The IP address can be an IPv4 or IPv6 address.

Parameter type: string.

Unit: none

Value range: a string, which complies with the identifier naming convention

Default value: ""

Setting method: This is a SIGHUP parameter. Set it based on instructions provided in Table 1.

Setting suggestion: Retain the default value.

Risks and impacts of improper settings: Change the parameter value after fully understanding the parameter meaning and verifying it through testing.

local_host

Parameter description: Specifies the HA local address. Set this parameter based on the cluster configuration file. You do not need to manually set this parameter. The IP address can be an IPv4 or IPv6 address.

Parameter type: string.

Unit: none

Value range: a string, which complies with the identifier naming convention

Default value: ""

Setting method: This is a SIGHUP parameter. Set it based on instructions provided in Table 1.

Setting suggestion: Retain the default value.

Risks and impacts of improper settings: Change the parameter value after fully understanding the parameter meaning and verifying it through testing.

active_port

Parameter description: Specifies the port number of the target GTM server.

Parameter type: integer.

Unit: none

Value range: 0 to 2147483647. The recommended value range is 1024 to 65535.

Default value: 0

Setting method: This is a SIGHUP parameter. Set it based on instructions provided in Table 1.

Setting suggestion: Retain the default value.

Risks and impact of improper settings: This parameter is specified in the configuration file during installation. Do not modify this parameter unless necessary. Otherwise, database communications will be affected after the modification.

local_port

Parameter description: Specifies the local port for HA.

Parameter type: integer.

Unit: none

Value range: 0 to 2147483647. The recommended value range is 1024 to 65535.

Default value: 0

Setting method: This is a SIGHUP parameter. Set it based on instructions provided in Table 1.

Setting suggestion: Retain the default value.

Risks and impact of improper settings: This parameter is specified in the configuration file during installation. Do not modify this parameter unless necessary. Otherwise, database communications will be affected after the modification.

standby_connection_timeout

Parameter description: Specifies the timeout interval between the primary and standby GTMs. A larger value enhances the fault tolerance capability of the network between the primary and standby GTMs, but increases the duration for reporting disconnection between them.

Parameter type: integer.

Unit: second

Value range: 5 to 2147483647

Default value: 5

Setting method: This is a SIGHUP parameter. Set it based on instructions provided in Table 1.

Setting suggestion: Retain the default value.

Risks and impact of improper settings: If the value is too large, disconnection faults may not be detected in a timely manner.

keepalives_count

Parameter description: Specifies the maximum number of unresponsive keepalive signals that can be waited before the GTM server is disconnected from the client on an OS that supports the TCP_KEEPCNT socket option. This parameter takes effect only on the standby GTM.

Parameter type: integer.

Unit: none

Value range: 0 to 2147483647

Default value: 0, indicating that the connection is immediately broken if no keepalive signal from the client is received by the GTM.

Setting method: This is a POSTMASTER parameter. Set it based on instructions provided in Table 1.

Setting suggestion: Retain the default value.

Risks and impacts of improper settings: Change the parameter value after fully understanding the parameter meaning and verifying it through testing.

keepalives_idle

Parameter description: Specifies the interval for sending keepalive signals if no data is sent after the GTM server is connected to the client on the OS that supports the TCP_KEEPIDLE socket option.

Parameter type: integer.

Unit: second

Value range: 0 to 2147483647

Default value: 0

Setting method: This is a POSTMASTER parameter. Set it based on instructions provided in Table 1.

Setting suggestion: Retain the default value.

Risks and impacts of improper settings: Change the parameter value after fully understanding the parameter meaning and verifying it through testing.

keepalives_interval

Parameter description: Specifies the interval at which the GTM server sends active signals on the OS that supports the TCP_KEEPINTVL socket option.

Parameter type: integer.

Unit: second

Value range: 0 to 2147483647

Default value: 0

Setting method: This is a POSTMASTER parameter. Set it based on instructions provided in Table 1.

Setting suggestion: Retain the default value.

Risks and impacts of improper settings: Change the parameter value after fully understanding the parameter meaning and verifying it through testing.

synchronous_backup

Parameter description: Specifies whether to enable synchronization for backing up data to the standby GTM.

Parameter type: enumerated type.

Unit: none

Value range:

• on: Synchronization is enabled.
• off: Synchronization is disabled.
• auto: Automatic synchronization is enabled.

Default value: auto

Setting method: This is a SIGHUP parameter. Set it based on instructions provided in Table 1.

Setting suggestion: Retain the default value.

Risks and impacts of improper settings: Change the parameter value after fully understanding the parameter meaning and verifying it through testing.

query_memory_limit

Parameter description: Specifies the limit of memory available for queries. This parameter applies only to the default resource group. For other resource groups, the memory available for queries is not limited.

Parameter type: floating point.

Unit: none

Value range: 0.0 to 1.0

Default value: 0.25

Setting method: This is a POSTMASTER parameter. Set it based on instructions provided in Table 1.

Setting suggestion: Retain the default value.

Risks and impacts of improper settings: Change the parameter value after fully understanding the parameter meaning and verifying it through testing.

wlm_max_mem

Parameter description: Specifies the maximum memory for GTM execution.

Parameter type: integer.

Unit: MB

Value range: 512 to 2147483647

Default value: 2048

Setting method: This is a POSTMASTER parameter. Set it based on instructions provided in Table 1.

Setting suggestion: Retain the default value.

Risks and impacts of improper settings: Change the parameter value after fully understanding the parameter meaning and verifying it through testing.

config_file

Parameter description: Specifies the name of a GTM configuration file. Only the SYSADMIN user can access this parameter.

Parameter type: string.

Unit: none

Value range: valid file name.

Default value: "gtm.conf"

Setting method: This is a POSTMASTER parameter. Set it based on instructions provided in Table 1.

Setting suggestion: Retain the default value.

Risks and impacts of improper settings: Change the parameter value after fully understanding the parameter meaning and verifying it through testing.

data_dir

Parameter description: Specifies the GTM data file directory.

Parameter type: string.

Unit: none

Value range: valid path of a directory.

Default value: ""

Setting method: This is a POSTMASTER parameter. Set it based on instructions provided in Table 1.

Setting suggestion: Retain the default value.

Risks and impacts of improper settings: Change the parameter value after fully understanding the parameter meaning and verifying it through testing.

listen_addresses

Parameter description: Specifies the TCP/IP address of the client for a server to listen on. The IP address can be an IPv4 or IPv6 address.

Parameter type: string.

Unit: none

Value range:

• Host name or IP address. Multiple values are separated with commas (,). IPv4 and IPv6 addresses are supported.
• An asterisk (*), indicating all IP addresses.
• If the parameter is not specified, the server does not listen on any IP address. In this case, only UDS can be used for database connections.

Default value: "*"

Setting method: This is a POSTMASTER parameter. Set it based on instructions provided in Table 1.

Setting suggestion: Retain the default value.

Risks and impacts of improper settings: Change the parameter value after fully understanding the parameter meaning and verifying it through testing.

log_directory

Parameter description: Specifies the directory for storing log files when logging_collector is set to on. The value can be an absolute path, or relative to the data directory.

• If the value of log_directory in the configuration file is an invalid path (that is, the user does not have the permission to read or write this path), the cluster cannot be restarted.
• If the value of log_directory is changed to a valid path (that is, the user has the permission to read and write this path), logs are generated in the new path. If the specified path is invalid, log files are generated in the last valid path and the database running is not affected. The invalid value is still written into the configuration file.

Parameter type: string.

Unit: none

Value range: valid path of a directory.

Default value: gtm_log, indicating that server logs will be generated in the gtm_log/ directory under the data directory.

Setting method: This is a SIGHUP parameter. Set it based on instructions provided in Table 1.

Setting suggestion: Retain the default value.

Risks and impacts of improper settings: Change the parameter value after fully understanding the parameter meaning and verifying it through testing.

log_min_messages

Parameter description: Specifies the level of messages written to GTM log files in the server log folder. When a message of the same or higher level is generated, the message is recorded in the log file. Therefore, a lower level indicates that more messages are recorded in the run log of the server.

Parameter type: enumerated type.

Unit: none

Value range: The message levels are debug5, debug4, debug3, debug2 (debug), debug1, info, notice, warning, error, log, fatal, and panic in ascending order. For details about the parameters, see Table 1.

• The message level debug is equivalent to debug2.
• For log_min_messages, the log message level is higher than error and lower than fatal.

Default value: warning

Setting method: This is a SIGHUP parameter. Set it based on instructions provided in Table 1.

Setting suggestion: Retain the default value.

Risks and impacts of improper settings: Change the parameter value after fully understanding the parameter meaning and verifying it through testing.

alarm_component

Parameter description: Certain alarms are suppressed during alarm reporting. That is, the same alarm will not be repeatedly reported by an instance within the period specified by alarm_report_interval. Its default value is 10s. In this case, the parameter specifies the location of the alarm component that is used to process alarm information.

Parameter type: string.

Unit: none

Value range:

• If --alarm-type in the gs_preinstall script is set to 5, no third-party component is connected and alarms are written into the system_alarm log. In this case, the value of alarm_component is /opt/huawei/snas/bin/snas_cm_cmd.
• If --alarm-type in the gs_preinstall script is set to 1, a third-party component is connected. In this case, the value of alarm_component is the absolute path of the executable program of the third-party component.

Default value: "/opt/huawei/snas/bin/snas_cm_cmd"

Setting method: This is a POSTMASTER parameter. Set it based on instructions provided in Table 1.

Setting suggestion: Retain the default value.

Risks and impacts of improper settings: Change the parameter value after fully understanding the parameter meaning and verifying it through testing.

alarm_report_interval

Parameter description: Specifies the interval at which an alarm is reported.

Parameter type: integer.

Unit: second

Value range: 0 to 2147483647

Default value: 10

Setting method: This is a SIGHUP parameter. Set it based on instructions provided in Table 1.

Setting suggestion: Retain the default value.

Risks and impacts of improper settings: Change the parameter value after fully understanding the parameter meaning and verifying it through testing.

standby_only

Parameter description: Specifies whether to forcibly synchronize information to standby nodes. In the mode with one primary and multiple standby nodes, information is only forcibly synchronized to the ETCD.

Parameter type: integer.

Unit: none

Value range:

• 0: Information is not forcibly synchronized to standby nodes.
• 1: Information is forcibly synchronized to standby nodes.

Default value: 0

Setting method: This is a SIGHUP parameter. Set it based on instructions provided in Table 1.

Setting suggestion: Retain the default value.

Risks and impacts of improper settings: Change the parameter value after fully understanding the parameter meaning and verifying it through testing.

gtm_max_trans

Parameter description: Specifies the maximum number of connections accepted by the GTM. You are advised not to change the value.

Parameter type: integer.

Unit: none

Value range: 256 to 200000

Default value: 8192

Setting method: This is a POSTMASTER parameter. Set it based on instructions provided in Table 1.

Setting suggestion: Retain the default value. If you have to, set this parameter to a value no less than the maximum number of connections plus 100.

Risks and impacts of improper settings: Change the parameter value after fully understanding the parameter meaning and verifying it through testing.

enable_connect_control

Parameter description: Specifies whether the GTM connection control is enabled to check whether a connection IP address is within the cluster.

Parameter type: Boolean.

Unit: none

Value range:

• on: Checks whether a connection IP address is within the cluster. If it is not, the access is rejected.
• off: Does not check whether a connection IP address is within the cluster.

Default value: on

Setting method: This is a SIGHUP parameter. Set it based on instructions provided in Table 1.

Setting suggestion: Retain the default value.

Risks and impacts of improper settings: Change the parameter value after fully understanding the parameter meaning and verifying it through testing.

gtm_authentication_type

Parameter description: Specifies the port authentication mode of the GTM module.

Parameter type: enumerated type.

Unit: none

Value range:

• trust: Port authentication is not configured.
• gss: Kerberos port authentication is used.
  

  Note that you can change the value to gss only after the Kerberos server and client are successfully installed. Otherwise, the GTM cannot communicate properly, affecting the cluster status.

Default value: trust

Setting method: This is a SIGHUP parameter. Set it based on instructions provided in Table 1.

Setting suggestion: Retain the default value.

Risks and impacts of improper settings: Change the parameter value after fully understanding the parameter meaning and verifying it through testing.

gtm_krb_server_keyfile

Parameter description: Specifies the location of the key file on the Kerberos server. The value must be an absolute path. The file is usually stored in the ${GAUSSHOME}/kerberos directory and ends with keytab. The file name is the same as the name of the user who runs the cluster. This parameter is used together with gtm_authentication_type. If gtm_authentication_type is changed to gss, this parameter must be configured as the correct path. Otherwise, the cluster status will be affected.

Parameter type: string.

Unit: none

Value range: valid file path.

Default value: ""

Setting method: This is a POSTMASTER parameter. Set it based on instructions provided in Table 1.

Setting suggestion: Retain the default value.

Risks and impacts of improper settings: Change the parameter value after fully understanding the parameter meaning and verifying it through testing.

gtm_option

Parameter description: Specifies the GTM mode. This parameter must be configured on all GTMs, CNs, and DNs. The value must be the same. There are three GTM modes: GTM, GTM-lite, and GTM-free. The GTM and GTM-Lite modes take effect only when the enable_gtm_free parameter is set to off. The current version does not support switching between different GTM modes for installed clusters.

Parameter type: integer.

Unit: none

Value range: 0 to 2

• 0: GTM mode.
• 1: GTM-lite mode.
• 2: GTM-free mode.

Default value: 1

Setting method: This is a POSTMASTER parameter. Set it based on instructions provided in Table 1.

Setting suggestion: Retain the default value.

Risks and impacts of improper settings: Change the parameter value after fully understanding the parameter meaning and verifying it through testing.

csn_sync_interval

Parameter description: Specifies the interval for synchronizing CSN between the primary and standby GTMs.

Parameter type: integer.

Unit: second

Value range: 1 to 2147483647

Default value: 1

Setting method: This is a SIGHUP parameter. Set it based on instructions provided in Table 1.

Setting suggestion: Retain the default value.

Risks and impacts of improper settings: Change the parameter value after fully understanding the parameter meaning and verifying it through testing.

restore_duration

Parameter description: Specifies the reply interval of XID or CSN on the GTM, that is, the number of XIDs or CSNs for reply.

Parameter type: integer.

Unit: none

Value range: 1000000 to 2147483647

Default value: 1000000

Setting method: This is a POSTMASTER parameter. Set it based on instructions provided in Table 1.

Setting suggestion: Retain the default value.

Risks and impacts of improper settings: Change the parameter value after fully understanding the parameter meaning and verifying it through testing.

gtm_enable_threadpool

Parameter description: Specifies whether to enable the GTM thread pool function. The setting takes effect only after the GTM is restarted.

Parameter type: Boolean.

Unit: none

Value range:

• on: The GTM thread pool function is enabled.
• off: The GTM thread pool function is disabled.

Default value: on

Setting method: This is a POSTMASTER parameter. Set it based on instructions provided in Table 1.

Setting suggestion: Retain the default value.

Risks and impacts of improper settings: Change the parameter value after fully understanding the parameter meaning and verifying it through testing.

gtm_num_threads

Parameter description: Specifies the number of work threads in the thread pool when the thread pool function gtm_enable_threadpool is enabled.

Parameter type: integer.

Unit: none

Value range: 0 to 16384. The value is related to the size of gtm_max_trans and cannot exceed the result of (Value of gtm_max_trans – 1 – Number of auxiliary threads). The number of auxiliary threads is 2 in the current version.

Default value: 1024

Setting method: This is a POSTMASTER parameter. Set it based on instructions provided in Table 1.

Setting suggestion: Retain the default value.

Risks and impacts of improper settings: Change the parameter value after fully understanding the parameter meaning and verifying it through testing.

check_gtm_primary_time

Parameter description: Specifies the interval at which GTM checks the consistency between its primary node and ETCD primary node.

Parameter type: integer.

Unit: second

Value range: 0 to 2147483647. The value 0 indicates that the detection function is disabled.

Default value: 2

Setting method: This is a SIGHUP parameter. Set it based on instructions provided in Table 1.

Setting suggestion: Set this parameter based on service requirements.

Risks and impacts of improper settings: Change the parameter value after fully understanding the parameter meaning and verifying it through testing.