CM Server Parameters
log_dir
Parameter description: Specifies the directory where CM Server logs are stored. The value can be an absolute path, or a path relative to the CM Server data directory.
Parameter type: string.
Unit: none
Value range: valid path of a directory.
Default value: "$GAUSSLOG/cm/cm_server", indicating that the CM Server logs are generated in the CM directory in $GAUSSLOG.
Setting method: This parameter is a CM parameter. For details about how to modify this parameter, see method 1 in Table 2. The modification takes effect only after the CM Server is restarted.
Setting suggestion: Retain the default value.
Risks and impacts of improper settings: Change the parameter value after you fully understand the parameter meaning and test the parameter to avoid unexpected results.
log_file_size
Parameter description: Specifies the size of a log file. If a log file exceeds the specified size, a new one is created to record logs.
Parameter type: integer.
Unit: MB
Value range: 0 to 2047
Default value: 16
Setting method: This parameter is a CM parameter. For details about how to modify this parameter, see method 1 and method 2 in Table 2. For example, if this parameter is set to 16 without a unit, it indicates 16 MB. If this parameter is set to 16MB, it indicates 16 MB. The unit must be MB if required.
Setting suggestion: Retain the default value.
Risks and impacts of improper settings: Change the parameter value after you fully understand the parameter meaning and test the parameter to avoid unexpected results.
log_min_messages
Parameter description: Specifies which message levels are written to the CM Server log. Each level covers all the levels following it. A lower level indicates that fewer messages will be written into the run log on the server.
Value type: enumerated type.
Unit: none
Value range: debug5, debug1, log, warning, error, and fatal.
Default value: warning
Setting method: This parameter is a CM parameter. For details about how to modify this parameter, see method 1 and method 2 in Table 2.
Setting suggestion: Set this parameter based on the hard disk size.
Risks and impacts of improper settings: If the level is set to a low value, debugging information may be lost.
thread_count
Parameter description: Specifies the number of threads in the agent thread pool.
Parameter type: string.
Unit: none
Value range: This parameter consists of two parts: 'worker_thread_count and io_ratio. The meanings of the two parts are as follows:
- worker_thread_count: specifies the number of AgentWorker threads. The value ranges from 2 to 1000.
- io_ratio: specifies the ratio of I/O threads to worker threads. The value n indicates that one AgentIO thread corresponds to n AgentWorker threads. The value ranges from 1 to 100. At least one AgentIO thread is required.
Default value: "(1000,1)"
Setting method: This parameter is a CM parameter. For details about how to modify this parameter, see method 1 in Table 2. The modification takes effect only after the CM Server is restarted.
Setting suggestion: Retain the default value. If you want to adjust the value, make sure you understand the parameter meaning and adjust the value with caution to avoid risks caused by misoperations.
Risks and impacts of improper settings: If this parameter is incorrectly set, CM faults may not be detected and rectified in a timely manner, and the CPU load may increase.
alarm_component
Parameter description: Specifies the location of the alarm component that processes alarms.
Parameter type: string.
Unit: none
Value range: valid file path.
- If --alarm-type in the gs_preinstall script is set to 5, no third-party component is connected and alarms are written into system_alarm logs. 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 parameter is a CM parameter. For details about how to modify this parameter, see method 1 and method 2 in Table 2.
Setting suggestion: Retain the default value.
Risks and impacts of improper settings: Change the parameter value after you fully understand the parameter meaning and test the parameter to avoid unexpected results.
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: 3
Setting method: This parameter is a CM parameter. For details about how to modify this parameter, see method 1 and method 2 in Table 2.
Setting suggestion: Retain the default value.
Risks and impacts of improper settings: If the value is too large, alarms may not be reported in a timely manner. If the value is too small, the CPU load may increase.
alarm_report_max_count
Parameter description: Specifies the maximum number of times an alarm is reported.
Parameter type: integer.
Unit: none
Value range: 1 to 2592000
Default value: 1
Setting method: This parameter is a CM parameter. For details about how to modify this parameter, see method 1 and method 2 in Table 2.
Setting suggestion: Retain the default value.
Risks and impacts of improper settings: If the value is too large, the CPU load may increase.
instance_failover_delay_timeout
Parameter description: Specifies the delay in CM Server failover after the primary CM Server breakdown is detected. It takes effect for DN arbitration in primary/standby/secondary mode.
Parameter type: integer.
Unit: second
Value range: 0 to 2147483647
Default value: 0
Setting method: This parameter is a CM parameter. For details about how to modify this parameter, see method 1 and method 2 in Table 2.
Setting suggestion: Retain the default value.
Risks and impacts of improper settings: If the value is too large, database faults may not be rectified in a timely manner.
instance_heartbeat_timeout
Parameter description: Specifies the timeout interval for CM Server to detect the instance heartbeat.
Parameter type: integer.
Unit: second
Value range: 1 to 2147483647
Default value: 6
Setting method: This parameter is a CM parameter. For details about how to modify this parameter, see method 1 and method 2 in Table 2.
Setting suggestion: Retain the default value.
Risks and impacts of improper settings: If the value is too large or too small, false negative and false positive may occur during fault detection.
instance_keep_heartbeat_timeout
Parameter description: The CM Agent periodically checks the instance status and reports the status to the CM Server. If the instance status cannot be detected for a long time and the accumulated time exceeds the value of this parameter, the CM Server delivers a command to the CM Agent to restart the instance.
Parameter type: integer.
Unit: second
Value range: 0 to 2147483647
Default value: 40
Setting method: This parameter is a CM parameter. For details about how to modify this parameter, see method 1 and method 2 in Table 2.
Setting suggestion: Retain the default value.
Risks and impacts of improper settings: If the value is too large or too small, false negative and false positive may occur during fault detection.
instance_phony_dead_restart_interval
Parameter description: Specifies the interval at which the CM Agent process restarts and kills a zombie DN instance. The interval between two consecutive kill operations cannot be less than the value of this parameter. Otherwise, the CM Agent process does not deliver the restart command.
Parameter type: integer.
Unit: second
Value range: 0 to 2147483647. The minimum value that takes effect is 1800. If this parameter is set to a value less than 1800, the value 1800 takes effect.
Default value: 21600
Setting method: This parameter is a CM parameter. For details about how to modify this parameter, see method 1 and method 2 in Table 2.
Setting suggestion: Retain the default value.
Risks and impacts of improper settings: If the value is too large or too small, false negative and false positive may occur during fault detection.
phony_dead_effective_time
Parameter description: Specifies the maximum number of times DN processes are detected as zombie. If the number of times a process is detected as zombie is greater than the specified value, the process is considered to be a zombie process and will be restarted.
Parameter type: integer.
Unit: none
Value range: 1 to 2147483647
Default value: 5
Setting method: This parameter is a CM parameter. For details about how to modify this parameter, see method 1 and method 2 in Table 2.
Setting suggestion: Retain the default value.
Risks and impacts of improper settings: If the value is too large or too small, false negative and false positive may occur during fault detection.
enable_transaction_read_only
Parameter description: Specifies whether to enable the threshold detection function of the CM Server disk. After this function is enabled, CM Server automatically sets the database to read-only when the disk usage is greater than the value of datastorage_threshold_value_check.
Parameter type: Boolean.
Unit: none
Value range:
- on: The threshold detection function is enabled.
- off: The threshold detection function is disabled.
Default value: on
Setting method: This parameter is a CM parameter. For details about how to modify this parameter, see method 1 and method 2 in Table 2.
Setting suggestion: Retain the default value.
Risks and impacts of improper settings: Disabling this function may cause high disk usage.
datastorage_threshold_check_interval
Parameter description: Specifies the interval for checking the disk usage. The system checks the disk usage at the interval specified by the user.
Parameter type: integer.
Unit: second
Value range: 1 to 2592000
Default value: 10
Setting method: This parameter is a CM parameter. For details about how to modify this parameter, see method 1 and method 2 in Table 2.
Setting suggestion: Retain the default value.
Risks and impacts of improper settings: If the value is too large, CM fault detection and recovery cannot be performed in a timely manner. If the value is too small, the CPU load increases.
datastorage_threshold_value_check
Parameter description: Specifies the usage threshold of a read-only disk in a database. When the disk usage of the data directory exceeds the specified value, the database is automatically set to read-only mode. In the read-only mode, log replay cannot be restricted and the disk usage increases. Therefore, you need to pay attention to the database instance disk capacity and handle read-only alarms in a timely manner to prevent the disk space from being used up; otherwise, the database cannot be restored quickly.
Parameter type: integer.
Unit: percentage
Value range: 1 to 99
Default value: 85
Setting method: This parameter is a CM parameter. For details about how to modify this parameter, see method 1 and method 2 in Table 2.
Setting suggestion: Retain the default value. You can adjust this parameter based on the disk space. When adjusting this parameter, you are advised to adjust the max_size_for_xlog_retention parameter of the DN at the same time to prevent the instance read-only threshold from being triggered by backup operations.
Risks and impacts of improper settings: If the value is too large, the disk space usage is too high and the restoration cannot be achieved quickly.
max_datastorage_threshold_check
Parameter description: Specifies the maximum interval for checking the disk usage. After you modify the read-only mode parameter, the system automatically checks whether the disk usage reaches the threshold at the specified interval.
Parameter type: integer.
Unit: second
Value range: 1 to 2592000
Default value: 43200
Setting method: This parameter is a CM parameter. For details about how to modify this parameter, see method 1 and method 2 in Table 2.
Setting suggestion: Retain the default value.
Risks and impacts of improper settings: If the value is too large, CM fault detection and recovery cannot be performed in a timely manner.
enable_az_auto_switchover
Parameter description: Specifies whether to enable the automatic AZ switchover function. If this function is enabled, CM Server can automatically switch over AZs. Otherwise, when a DN is faulty, services will not be automatically switched to another AZ even if the current AZ is unavailable. You can run the switchover command to manually switch services to another AZ.
Parameter type: integer.
Unit: none
Value range: 0 to 1
- 0: The automatic AZ switchover function is disabled.
- 1: The automatic AZ switchover function is enabled.
Default value: 1
Setting method: This parameter is a CM parameter. For details about how to modify this parameter, see method 1 and method 2 in Table 2.
Setting suggestion: Retain the default value.
Risks and impacts of improper settings: If this function is disabled, CM fault detection and recovery cannot be performed in a timely manner.
cmserver_ha_connect_timeout
Parameter description: Specifies the time to wait before the attempt of CM Server to connect to other CM Servers times out.
Parameter type: integer.
Unit: second
Value range: 0 to 2147483647
Default value: 2
Setting method: This parameter is a CM parameter. For details about how to modify this parameter, see method 1 and method 2 in Table 2.
Setting suggestion: Retain the default value.
Risks and impacts of improper settings: If the value is too large or too small, false negative and false positive may occur during fault detection.
cmserver_ha_heartbeat_timeout
Parameter description: Specifies the timeout interval for a CM Server to receive heartbeat signals from other CM Servers.
Parameter type: integer.
Unit: second
Value range: 1 to 2147483647
Default value: 6
Setting method: This parameter is a CM parameter. For details about how to modify this parameter, see method 1 and method 2 in Table 2.
Setting suggestion: Retain the default value.
Risks and impacts of improper settings: If the value is too large or too small, false negative and false positive may occur during fault detection.
cmserver_ha_status_interval
Parameter description: Specifies the interval between synchronizations of primary and standby CM Server status.
Parameter type: integer.
Unit: second
Value range: 1 to 2147483647
Default value: 1
Setting method: This parameter is a CM parameter. For details about how to modify this parameter, see method 1 and method 2 in Table 2.
Setting suggestion: Retain the default value.
Risks and impacts of improper settings: If the value is too large, CM fault detection and recovery cannot be performed in a timely manner. If the value is too small, the CPU load increases.
cmserver_self_vote_timeout
Parameter description: Specifies the time to wait before the CM Server self-voting times out. This parameter is valid only when the value of this parameter is greater than or equal to that of cmserver_ha_heartbeat_timeout.
Parameter type: integer.
Unit: second
Value range: 0 to 2147483647
Default value: 6
Setting method: This parameter is a CM parameter. For details about how to modify this parameter, see method 1 and method 2 in Table 2.
Setting suggestion: Retain the default value.
Risks and impacts of improper settings: If the value is too large or too small, false negative and false positive may occur during fault detection.
cmserver_demote_delay_on_etcd_fault
Parameter description: Specifies the delay within which CM Server switches from the primary state to the standby state due to unhealthy ETCD.
Parameter type: integer.
Unit: second
Value range: 1 to 2147483647
Default value: 8
Setting method: This parameter is a CM parameter. For details about how to modify this parameter, see method 1 and method 2 in Table 2.
Setting suggestion: Retain the default value.
Risks and impacts of improper settings: If the value is too small, the ETCD fault detection result is false positive. If the value is too large, the CM fault cannot be rectified in a timely manner.
cm_auth_method
Parameter description: Specifies the port authentication mode of the CM module.
Value type: enumerated type.
Unit: none
Value range:
- trust: Port authentication is not configured.
- gss: Kerberos port authentication is used.
Default value: trust
Setting method: This parameter is a CM parameter. For details about how to modify this parameter, see method 1 and method 2 in Table 2.
Setting suggestion: Retain the default value.
Risks and impacts of improper settings: You can change the value to "gss" only after the Kerberos server and client are successfully installed. Otherwise, the CM cannot communicate properly, affecting the database status.
cm_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 database.
Parameter type: string.
Unit: none
Value range: absolute path of the key file of the Kerberos server.
Default value: ${GAUSSHOME}/kerberos/{UserName}.keytab. The default value cannot take effect and is used only as a prompt.
Setting method: This parameter is a CM parameter. For details about how to modify this parameter, see method 1 and method 2 in Table 2.
Setting suggestion: Retain the default value.
Risks and impacts of improper settings: This parameter is paired with the preceding parameter cm_auth_method. When cm_auth_method is set to "gss", this parameter must be set to a correct path. Otherwise, the database instance status will be affected.
cm_server_arbitrate_delay_base_time_out
Parameter description: Specifies the basic delay duration for CM Server arbitration. If the primary CM Server is disconnected, the arbitration starts to be timed. If the disconnection duration exceeds the arbitration delay duration, a new primary CM Server will be selected. The arbitration delay duration is determined by the basic delay duration, the node index (server ID), and the incremental delay duration. The formula is as follows: Arbitration delay duration = Basic delay duration + Node index x Incremental delay duration.
Parameter type: integer.
Unit: second
Value range: 0 to 2147483647
Default value: 10
Setting method: This parameter is a CM parameter. For details about how to modify this parameter, see method 1 and method 2 in Table 2.
Setting suggestion: Retain the default value.
Risks and impacts of improper settings: If the value is too small, the CM Server disconnection fault is false positive. If the value is too large, the CM fault cannot be rectified in a timely manner.
cm_server_arbitrate_delay_incrememtal_time_out
Parameter description: Specifies the incremental delay duration for CM Server arbitration. If the primary CM Server is disconnected, the arbitration starts to be timed. If the disconnection duration exceeds the arbitration delay duration, a new primary CM Server will be selected. The arbitration delay duration is determined by the basic delay duration, the node index (server ID), and the incremental delay duration. The formula is as follows: Arbitration delay duration = Basic delay duration + Node index x Incremental delay duration.
Parameter type: integer.
Unit: second
Value range: 0 to 2147483647
Default value: 3
Setting method: This parameter is a CM parameter. For details about how to modify this parameter, see method 1 and method 2 in Table 2.
Setting suggestion: Retain the default value.
Risks and impacts of improper settings: If the value is too small, the CM Server disconnection fault is false positive. If the value is too large, the CM fault cannot be rectified in a timely manner.
force_promote
Parameter description: Specifies whether CM Server enables forcible switchover (that is, when the database status is unknown, the basic functions of the database are available at the cost of data loss). This parameter applies to DNs.
Parameter type: integer.
Unit: none
Value range: 0 to 1
- 0: The forced switching logic function is disabled.
- 1: The forcible switchover logic function is enabled.
Default value: 0
Setting method: This parameter is a CM parameter. For details about how to modify this parameter, see method 1 and method 2 in Table 2.
Setting suggestion: If you can accept the loss of some data caused by forcible service (system) switchover, enable this parameter when the service recovery has the highest priority.
Risks and impacts of improper settings: Change the parameter value after you fully understand the parameter meaning and test the parameter to avoid unexpected results.
switch_rto
Parameter description: Specifies the delay for the forcible switchover of CM Server. When force_promote is set to 1 and a shard in the database does not have primary CM Server, the system starts timing. After the delay, forcible switchover is executed.
Parameter type: integer.
Unit: second
Value range: 60 to 2147483647
Default value: 600
Setting method: This parameter is a CM parameter. For details about how to modify this parameter, see method 1 and method 2 in Table 2.
Setting suggestion: Retain the default value.
Risks and impacts of improper settings: If the value is too small, the database fault is false positive. If the value is too large, the fault cannot be rectified in a timely manner.
enable_finishredo_retrieve
Parameter description: Specifies whether to retrieve data of Xlogs that are cut off by redo logs after a forcible CM Server switchover. If this parameter is set to on, data is automatically retrieved after a forcible switchover.
Parameter type: Boolean.
Unit: none
Value range:
- on: Data is retrieved.
- off: Data is not retrieved.
Default value: off
Setting method: This parameter is a CM parameter. For details about how to modify this parameter, see method 1 and method 2 in Table 2.
Setting suggestion: Adjust the value according to the actual situation.
Risks and impacts of improper settings: Change the parameter value after you fully understand the parameter meaning and test the parameter to avoid unexpected results.
backup_open
Parameter description: Specifies the standby database instance for DR settings. After this parameter is enabled, CM runs in standby database instance for DR mode.
Parameter type: integer.
Unit: none
Value range: 0 to 3
- 0: No DR relationship is established.
- 1: The Dorado DR relationship is established.
- 2: The streaming replication-based DR relationship is established.
- 3: The logical DR relationship is established.
Default value: 0
Setting method: This parameter is a CM parameter. For details about how to modify this parameter, see method 1 in Table 2. The modification takes effect only after the CM Server is restarted.
Setting suggestion: This parameter cannot be enabled for a non-standby database instance for DR. This parameter is internally called. You are advised not to modify it.
Risks and impacts of improper settings: Changing the value of this parameter may cause unexpected results in the database. Retain the default value.
enable_dcf
Parameter description: Specifies the status of the DCF mode.
Parameter type: Boolean.
Unit: none
Value range:
- on: The DCF mode is enabled.
- off: The DCF mode is disabled.
Default value: off
Setting method: This parameter is a CM parameter. For details about how to modify this parameter, see method 1 and method 2 in Table 2.
Setting suggestion: Retain the default value.
Risks and impacts of improper settings: Change the parameter value after you fully understand the parameter meaning and test the parameter to avoid unexpected results.
install_type
Parameter description: Specifies the settings related to the standby database instance for DR, which are used to distinguish the database instance type.
Parameter type: integer.
Unit: none
Value range: 0 to 2
- 0: a database instance for which the DR relationship is not established.
- 1: a Dorado-based database instance.
- 2: a streaming-based database instance.
Default value: 0
Setting method: This parameter is a CM parameter. For details about how to modify this parameter, see method 1 in Table 2. The modification takes effect only after the CM Server is restarted.
Setting suggestion: This parameter cannot be enabled for a non-standby database instance for DR.
Risks and impacts of improper settings: Change the parameter value after you fully understand the parameter meaning and test the parameter to avoid unexpected results.
enable_ssl
Parameter description: Specifies whether to enable SSL.
Parameter type: Boolean.
Unit: none
Value range:
- on: The SSL certificate is enabled for encrypted communication.
- off: The SSL certificate is disabled for encrypted communication.
Default value: off
Setting method: This parameter is a CM parameter. For details about how to modify this parameter, see method 1 in Table 2. The modification takes effect only after the CM Server is restarted.
Setting suggestion: To ensure security, you are advised not to disable it. After this function is disabled, CM does not use encrypted communication and all information is transmitted in plaintext, which may bring security risks such as eavesdropping, tampering, and spoofing.
Risks and impacts of improper settings: After this function is disabled, CM does not use encrypted communication. All information is transmitted in plaintext, which may cause security risks such as eavesdropping, tampering, and spoofing.
ssl_cert_expire_alert_threshold
Parameter description: Specifies the SSL certificate expiration alarm time. If the certificate expiration time is less than the value of this parameter, an alarm indicating that the certificate is about to expire is reported.
Parameter type: integer.
Unit: day
Value range: 7–180
Default value: 90
Setting method: This parameter is a CM parameter. For details about how to modify this parameter, see method 1 in Table 2. The modification takes effect only after the CM Server is restarted.
Setting suggestion: Adjust the value according to the actual situation.
Risks and impacts of improper settings: If the value is too small, alarms may not be reported in a timely manner.
ssl_cert_expire_check_interval
Parameter description: Specifies the period for checking whether the SSL certificate expires.
Parameter type: integer.
Unit: second
Value range: 0 to 2147483647
Default value: 86400 (that is, one day)
Setting method: This parameter is a CM parameter. For details about how to modify this parameter, see method 1 in Table 2. The modification takes effect only after the CM Server is restarted.
Setting suggestion: Adjust the value according to the actual situation.
Risks and impacts of improper settings: If the value is too small, the CPU load increases. If the value is too large, alarms cannot be reported in a timely manner.
delay_arbitrate_timeout
Parameter description: Specifies the waiting time for a node in the same AZ as the primary DN to be promoted to primary after redo replay.
Parameter type: integer.
Unit: second
Value range: 0 to 2147483647
Default value: 0
Setting method: This parameter is a CM parameter. For details about how to modify this parameter, see method 1 and method 2 in Table 2.
Setting suggestion: Retain the default value.
Risks and impacts of improper settings: If the value is too large, DN faults may not be rectified in a timely manner.
ddb_type
Parameter description: Specifies whether to switch between ETCD and DCC modes.
Parameter type: integer.
Unit: none
Value range: 0 to 1
- 0: The ETCD mode is enabled.
- 1: The DCC mode is enabled.
Default value: 0
Setting method: This parameter is a CM parameter. For details about how to modify this parameter, see method 1 in Table 2. The modification takes effect only after the CM Server is restarted.
Setting suggestion: Retain the default value.
Risks and impacts of improper settings: Change the parameter value after you fully understand the parameter meaning and test the parameter to avoid unexpected results.
ddb_log_level
Parameter description: Specifies the DDB log level.
Parameter type: string.
Unit: none
Value range:
- "NONE": Disable the log function. It cannot be used together with the following log levels:
- "RUN_ERR|RUN_WAR|RUN_INF|DEBUG_ERR|DEBUG_WAR|DEBUG_INF|TRACE|PROFILE|OPER": Enable the log function. You can set this parameter to one or a combination of the preceding log levels. If two or more log levels are used together, separate them with vertical bars (|). The log level cannot be set to an empty character string.
Default value: "RUN_ERR|RUN_WAR|DEBUG_ERR|OPER|RUN_INF|PROFILE"
Setting method: This parameter is a CM parameter. For details about how to modify this parameter, see method 1 and method 2 in Table 2.
Setting suggestion: Retain the default value.
Risks and impacts of improper settings: Change the parameter value after you fully understand the parameter meaning and test the parameter to avoid unexpected results.
ddb_log_backup_file_count
Parameter description: Specifies the maximum number of log files that can be saved.
Parameter type: integer.
Unit: none
Value range: 1 to 100
Default value: 10
Setting method: This parameter is a CM parameter. For details about how to modify this parameter, see method 1 and method 2 in Table 2.
Setting suggestion: Retain the default value.
Risks and impacts of improper settings: Change the parameter value after you fully understand the parameter meaning and test the parameter to avoid unexpected results.
ddb_max_log_file_size
Parameter description: Specifies the maximum number of bytes in a log.
Parameter type: string.
Unit: none
Value range: The value of this parameter consists of digits and a unit. The value ranges from 1 to 1000, in MB.
Default value: "10M"
Setting method: This parameter is a CM parameter. For details about how to modify this parameter, see method 1 and method 2 in Table 2.
Setting suggestion: Retain the default value.
Risks and impacts of improper settings: Change the parameter value after you fully understand the parameter meaning and test the parameter to avoid unexpected results.
ddb_log_suppress_enable
Parameter description: Specifies whether to enable the log suppression function.
Parameter type: integer.
Unit: none
Value range: 0 to 1
- 0: The log suppression function is disabled.
- 1: The log suppression function is enabled.
Default value: 0
Setting method: This parameter is a CM parameter. For details about how to modify this parameter, see method 1 and method 2 in Table 2.
Setting suggestion: Retain the default value.
Risks and impacts of improper settings: Change the parameter value after you fully understand the parameter meaning and test the parameter to avoid unexpected results.
ddb_election_timeout
Parameter description: Specifies the DCC election timeout period.
Parameter type: integer.
Unit: second
Value range: 1–600
Default value: 3
Setting method: This parameter is a CM parameter. For details about how to modify this parameter, see method 1 and method 2 in Table 2.
Setting suggestion: Retain the default value.
Risks and impacts of improper settings: Change the parameter value after you fully understand the parameter meaning and test the parameter to avoid unexpected results.
enable_e2e_rto
Parameter description: Specifies whether to enable the E2E RTO function. After this function is enabled, the hang-up detection period and network detection timeout interval are shortened. The CM can reach the E2E RTO indicator (RTO for a single instance ≤ 10s; RTO for combined faults ≤ 30s).
Parameter type: integer.
Unit: none
Value range: 0 to 1
- 0: The E2E RTO function is disabled.
- 1: The E2E RTO function is enabled.
Default value: 0
Setting method: This parameter is a CM parameter. For details about how to modify this parameter, see method 1 and method 2 in Table 2.
Setting suggestion: Retain the default value. You can adjust the value as required.
Risks and impacts of improper settings: Change the parameter value after you fully understand the parameter meaning and test the parameter to avoid unexpected results.
cma_fault_kill_instance_timeout
Parameter description: Specifies timeout interval for waiting for a DN to be reported after the internal status of the primary CM Server is set to unknown. The CM Server runs the pssh command to remotely kill the DN that fails to be reported and restart the DN process. This parameter is not added to the CM Server configuration file by default. You need to manually add it.
Parameter type: integer.
Unit: second
Value range: 0 to 21474836. 0 indicates disabled.
Default value: This parameter is enabled by default. The default value is (cm_server_num x agent_connect_timeout x agent_connect_retries + agent_heartbeat_timeout + 10).
Setting method: Refer to the set cm parameters table in "Unified Database Management Tool > cm_ctl Tool Introduction" in Tool Reference. Then run the reload command for the settings to take effect.
Setting suggestion: Retain the default value.
Risks and impacts of improper settings: Faults may not be rectified in a timely manner.
thread_effective_time
Parameter description: Specifies the timeout interval for a round of thread running. If the timeout occurs, the thread is suspended and the process automatically exits.
Parameter type: integer.
Unit: second
Value range: 0 to 1200. The value 0 indicates that the thread monitoring capability is disabled.
Default value: 20
Setting method: This parameter is a CM parameter. For details about how to modify this parameter, see method 1 and method 2 in Table 2.
Setting suggestion: You are advised not to change the parameter value. To adjust the value, contact Huawei technical support.
Risks and impacts of improper settings: Improper settings may cause inaccurate fault detection and delayed fault rectification.
enable_synclist_single_inst
Parameter description: Specifies whether to reduce copies to one primary and zero standby. After this function is enabled, the number of copies will be reduced to one primary and zero standby. If the parameter is incorrectly set, the default value is used.
Parameter type: Boolean.
Unit: none
Value range:
- on: This function is enabled.
- off: This function is disabled.
Default value: off
Setting method: This parameter is a CM parameter. For details about how to modify this parameter, see method 1 and method 2 in Table 2.
Setting suggestion: Retain the default value. To adjust the value, contact Huawei technical support.
Risks and impacts of improper settings: If this parameter is enabled and all standby nodes are faulty, the primary node automatically switches to the local submission mode. In this case, if the primary node is faulty again, unrecoverable impacts may occur.
ctl_thread_count
Parameter description: Specifies the number of threads in the ctl thread pool.
Parameter type: string.
Unit: none
Value range:
The value is a string of more than 0 characters. This parameter consists of two parts: worker_thread_count and io_ratio. The meanings of the two parts are as follows:
-
worker_thread_count: specifies the number of CtlWorker threads. The value ranges from 0 to 1000. If the value is 0, the number of CtlWorker threads is equal to the number of nodes in the database instance.
-
io_ratio: specifies the ratio of I/O threads to worker threads. The value n indicates that one CtlIO thread corresponds to n CtlWorker threads. The value ranges from 1 to 100. At least one CtlIO thread is required.
Default value: "(0,1)"
Setting method: Refer to the set cm parameters table in "Unified Database Management Tool > cm_ctl Tool Introduction" in Tool Reference. Then restart the CM Server for the settings to take effect.
Setting suggestion: Retain the default value.
Risks and impacts of improper settings: CM performance may deteriorate.
asyn_log_enable
Parameter description: Specifies whether to enable asynchronous logging. After this parameter is enabled, the CM Server starts asynchronous logging.
Parameter type: Boolean.
Unit: none
Value range:
- on: The CM Server starts asynchronous logging.
- off: The CM Server does not start asynchronous logging but uses serial logging.
Default value: on
Setting method: Refer to the set cm parameters table in "Unified Database Management Tool > cm_ctl Tool Introduction" in Tool Reference. Then run the reload command for the settings to take effect.
Setting suggestion: Retain the default value.
Risks and impacts of improper settings: If this parameter is disabled, logs may be lost.
asyn_log_max_buf_size
Parameter description: Specifies the size of the asynchronous log buffer. When asynchronous logs are stacked and the stacked logs exceed the buffer size, subsequent logs cannot be recorded.
Parameter type: integer.
Unit: KB
Value range: 1 to 1048576
Default value: 1024
Setting method: Refer to the set cm parameters table in "Unified Database Management Tool > cm_ctl Tool Introduction" in Tool Reference. Then run the reload command for the settings to take effect.
Setting suggestion: Adjust the value based on the memory and hard disk size.
Risks and impacts of improper settings: Change the parameter value after you fully understand the parameter meaning and test the parameter to avoid unexpected results.
asyn_log_fault_solution
Parameter description: Specifies the asynchronous log processing solution after a log disk fault is identified. When the CM detects that a log disk is faulty or the asynchronous log buffer overflows, the CM processes asynchronous logs based on the configuration.
Parameter type: integer.
Unit: none
Value range: 0 to 2
- 0: No extra processing is performed on logs. All logs are retained in the buffer until the buffer size reaches the upper limit. After the buffer size reaches the upper limit, no more logs are recorded.
- 1: Logs are filtered. After a log disk fault is identified, only key logs, alarms, and logs at the ERROR level or higher are saved to the buffer until the buffer size reaches the upper limit. After the buffer size reaches the upper limit, no more logs are recorded.
- 2: Logs are discarded. After a log disk fault is identified, only key logs and alarms are saved to the buffer until the buffer size reaches the upper limit. After the buffer size reaches the upper limit, no more logs are recorded.
Default value: 0
Setting method: Refer to the set cm parameters table in "Unified Database Management Tool > cm_ctl Tool Introduction" in Tool Reference. Then run the reload command for the settings to take effect.
Setting suggestion: Adjust the value based on the memory and hard disk size.
Risks and impacts of improper settings: Change the parameter value after you fully understand the parameter meaning and test the parameter to avoid unexpected results.
enable_isolate
Parameter description: Specifies whether to isolate instances.
Parameter type: integer.
Unit: none
Value range: 0 to 1
- 1: enabled. After this function is enabled, CM Server automatically isolates faulty instances.
- 0: disabled.
Default value: 1
Setting method: Refer to the set cm parameters table in "Unified Database Management Tool > cm_ctl Tool Introduction" in Tool Reference. Then run the reload command for the settings to take effect.
Setting suggestion: Retain the default value.
Risks and impacts of improper settings: Change the parameter value after you fully understand the parameter meaning and test the parameter to avoid unexpected results.
alarm_ddb_unhealth_threshold
Parameter description: Specifies the threshold for reporting an alarm for an unhealthy DDB.
Parameter type: integer.
Unit: none
Value range: 0 to 2592000
Default value: 5
Setting method: Refer to the set cm parameters table in "Unified Database Management Tool > cm_ctl Tool Introduction" in Tool Reference. Then run the reload command for the settings to take effect.
Setting suggestion: Retain the default value.
Risks and impacts of improper settings: Change the parameter value after you fully understand the parameter meaning and test the parameter to avoid unexpected results.
disk_full_threshold
Parameter description: Specifies the disk usage threshold in a database. When the disk usage of the data directory exceeds the specified value, the disk is full and the database is automatically stopped. When the disk usage is less than the value specified by datastorage_threshold_value_check, the database is automatically started. The value of disk_full_threshold takes effect only when it is greater than that of datastorage_threshold_value_check.
Parameter type: integer.
Unit: %
Value range: 1 to 99
Default value: 98
Setting method: Refer to the set cm parameters table in "Unified Database Management Tool > cm_ctl Tool Introduction" in Tool Reference. Then run the reload command for the settings to take effect.
Setting suggestion: Retain the default value.
Risks and impacts of improper settings: If the value is too large, other processes may be unavailable.
cm_hadr_process_type
Parameter description: Specifies the DR process ID.
Value type: enumerated type.
Unit: none
Value range:
- none: There is no process.
- failover: The database instance for DR is switched to primary.
- switchover_promote: The process of promoting the standby database instance for DR to the primary database instance during the primary/standby database instance switchover.
- switchover_demote: The process of demoting the primary database instance to the standby database instance for DR during the primary/standby database instance switchover.
Default value: none
Setting method: Refer to the set cm parameters table in "Unified Database Management Tool > cm_ctl Tool Introduction" in Tool Reference. Then run the reload command for the settings to take effect.
Setting suggestion: Retain the default value.
Risks and impacts of improper settings: Change the parameter value after you fully understand the parameter meaning and test the parameter to avoid unexpected results.
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