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.
Value range: a string. Any modification of this parameter takes effect only after CM Server is restarted. For details about how to modify this parameter, see Table 2.
Default value: "log", indicating that CM Server logs are generated in the CM Server data directory.
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 log information.
Value range: an integer ranging from 0 to 2047. The unit is MB. The modification of this parameter takes effect after reloading. For details about how to modify the parameter, see Table 2.
Default value: 16MB
log_min_messages
Parameter description: Specifies the level of messages to be written to the CM Server log. Each level covers all the levels following it. The lower the level is, the fewer messages will be written into the log.
Value range: enumerated type. Valid values are debug5, debug1, log, warning, error, and fatal. The modification of this parameter takes effect after reloading. For details about how to modify the parameter, see Table 2.
Default value: warning
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.
If the value of worker_thread_count, namely the number of AgentWorker threads, is greater than the sum of the number of cluster nodes and the number of threads for processing cm_ctl requests (if the number of cluster nodes is less than 32, one thread is used by default; otherwise, four threads are used), the value that takes effect is the sum of the number of cluster nodes and the number of threads for processing cm_ctl requests.
Default value: "(1000,1)"
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. 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.
alarm_component
Parameter description: Specifies the location of the alarm component that processes alarms.
Value range: a string. The modification of this parameter takes effect after reloading. For details about how to modify the parameter, see Table 2.
- 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
instance_failover_delay_timeout
Parameter description: Specifies the delay in the CM Server failover when the primary CM Server breakdown is detected.
Value range: an integer. The unit is s. The modification of this parameter takes effect after reloading. For details about how to modify the parameter, see Table 2.
Default value: 0
instance_heartbeat_timeout
Parameter description: Specifies the time to wait before the instance heartbeat times out.
Value range: an integer. The unit is s. The modification of this parameter takes effect after reloading. For details about how to modify the parameter, see Table 2.
Default value: 6
coordinator_heartbeat_timeout
Parameter description: Specifies the heartbeat timeout that triggers the automatic removal of faulty CNs. The setting of this parameter takes effect immediately, and you do not need to restart CM Server. If this parameter is set to 0, faulty CNs are not automatically removed.
Value range: an integer. The unit is s. The modification of this parameter takes effect after reloading. For details about how to modify the parameter, see Table 2.
Default value: 25
cmserver_ha_connect_timeout
Parameter description: Specifies the time to wait before the connection between the primary and standby CM Servers times out.
Value range: an integer. The unit is s. The modification of this parameter takes effect after reloading. For details about how to modify the parameter, see Table 2.
Default value: 2
cmserver_ha_heartbeat_timeout
Parameter description: Specifies the time to wait before the heartbeat between the primary and standby CM Servers times out.
Value range: an integer. The unit is s. The modification of this parameter takes effect after reloading. For details about how to modify the parameter, see Table 2.
Default value: 6
phony_dead_effective_time
Parameter description: Specifies the maximum number of times CN, DN, or GTM 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 as a zombie process and will be restarted.
Value range: an integer. The modification of this parameter takes effect after reloading. For details about how to modify the parameter, see Table 2.
Default value: 5
enable_transaction_read_only
Parameter description: Specifies whether to enable the automatic 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.
Value range: Boolean values on, off, true, false, yes, no, 1, and 0. The modification of this parameter takes effect after reloading. For details about how to modify the parameter, see Table 2.
Default value: on
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.
Value range: an integer. The unit is s. The modification of this parameter takes effect after reloading. For details about how to modify the parameter, see Table 2.
Default value: 10
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. Pay attention to the cluster 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 quickly restored.
Parameter type: integer.
Unit: percentage
Value range: 1 to 99
Default value: 85
Setting method: The modification of this parameter takes effect after reloading. For details about how to modify the parameter, see 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 cluster read-only threshold from being triggered by backup operations.
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.
Value range: an integer. The unit is s. The modification of this parameter takes effect after reloading. For details about how to modify the parameter, see Table 2.
Default value: 43200
cmserver_ha_status_interval
Parameter description: Specifies the interval between synchronizations of primary and standby CM Server status.
Value range: an integer. The unit is s. The modification of this parameter takes effect after reloading. For details about how to modify the parameter, see Table 2.
Default value: 1
cmserver_self_vote_timeout
Parameter description: Specifies the time to wait before the CM Server self-voting times out.
Value range: an integer. The unit is s. The modification of this parameter takes effect after reloading. For details about how to modify the parameter, see Table 2.
Default value: 6
alarm_report_interval
Parameter description: Specifies the interval at which an alarm is reported.
Value range: a non-negative integer. The unit is s. The modification of this parameter takes effect after reloading. For details about how to modify the parameter, see Table 2.
Default value: 3
alarm_report_max_count
Parameter description: Specifies the maximum number of times an alarm is reported.
Value range: a non-negative integer. The modification of this parameter takes effect after reloading. For details about how to modify the parameter, see Table 2.
Default value: 1
enable_az_auto_switchover
Parameter description: Specifies whether to enable automatic AZ switchover. If it is set to 1, CM Server automatically switches over services among 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.
Value range: a non-negative integer. 0: disabled; 1: enabled. The modification of this parameter takes effect after reloading. For details about how to modify the parameter, see Table 2.
Default value: 1
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 number of times exceeds the value of this parameter, the CM Server delivers a command to the CM Agent to restart the instance.
Value range: an integer. The unit is s. The modification of this parameter takes effect after reloading. For details about how to modify the parameter, see Table 2.
Default value: 40
az_switchover_threshold
Parameter description: If the failure rate of a DN shard in an AZ (Number of faulty DN shards/Total number of DN shards x 100%) exceeds the specified value, automatic AZ switchover is triggered.
Value range: an integer ranging from 0 to 100. The modification of this parameter takes effect after reloading. For details about how to modify the parameter, see Table 2.
Default value: 100
az_check_and_arbitrate_interval
Parameter description: Specifies the interval for checking the AZ status. If the status of an AZ is abnormal, automatic AZ switchover is triggered.
Value range: an integer. The unit is s. The modification of this parameter takes effect after reloading. For details about how to modify the parameter, see Table 2.
Default value: 2
az_connect_check_interval
Parameter description: Specifies the interval at which the network connection between AZs is checked.
Value range: an integer. The unit is s. The modification of this parameter takes effect after reloading. For details about how to modify the parameter, see Table 2.
Default value: 60
az_connect_check_delay_time
Parameter description: Specifies the delay between two retries to check the network connection between AZs.
Value range: an integer. The unit is s. The modification of this parameter takes effect after reloading. For details about how to modify the parameter, see Table 2.
Default value: 150
cmserver_demote_delay_on_etcd_fault
Parameter description: Specifies the interval at which CM Server switches from the primary state to the standby state due to unhealthy ETCD.
Value range: an integer. The unit is s. The modification of this parameter takes effect after reloading. For details about how to modify the parameter, see Table 2.
Default value: 8
instance_phony_dead_restart_interval
Parameter description: Specifies the interval at which the CM Agent process restarts and kills a zombie CN, DN, or GTM 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 commands.
Value range: an integer ranging from 1800 to 231 – 1. The unit is second. The modification of this parameter takes effect after reloading. For details about how to modify the parameter, see Table 2.
Default value: 21600
cm_auth_method
Parameter description: Specifies the port authentication mode of the CM. trust indicates that port authentication is not configured. gss indicates that 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 CM cannot communicate properly, affecting the cluster status.
Value range: gss or trust. The modification of this parameter takes effect after reloading. For details about how to modify the parameter, see Table 2.
Default value: trust
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 cluster. This parameter is used together with cm_auth_method. If the cm_auth_method parameter is changed to gss, this parameter must also be configured as the correct path. Otherwise, the cluster status will be affected.
Value range: a string. The modification of this parameter takes effect after reloading. For details about how to modify the parameter, see Table 2.
Default value: ${GAUSSHOME}/kerberos/{UserName}.keytab. The default value cannot take effect and is used only as a prompt.
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
Value range: an integer. The unit is s. The index should be larger than 0. The modification of this parameter takes effect after reloading. For details about how to modify the parameter, see Table 2.
Default value: 10
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
Value range: an integer. The unit is s. The index should be larger than 0. The modification of this parameter takes effect after reloading. For details about how to modify the parameter, see Table 2.
Default value: 3
force_promote
Parameter description: Specifies whether CM Server enables the forcible startup logic (that is, when the cluster status is unknown, ensure that the basic functions of the cluster are available at the cost of partial data loss). The value 0 indicates that forcible startup is disabled, and the value 1 indicates that forcible startup is enabled. This parameter applies to CNs and DNs.
Value range: 0 or 1. The modification of this parameter takes effect after reloading. For details about how to modify the parameter, see Table 2.
Default value: 0
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 cluster has no primary node, the system starts timing. After the delay, forcible switchover is executed.
Value range: an integer ranging from 0 to 2147483647. The unit is second. The minimum value that takes effect is 60. If this parameter is set to a value less than 60, 60s is used. The modification of this parameter takes effect after reloading. For details about how to modify the parameter, see Table 2.
Default value: 600
enable_finishredo_retrieve
Parameter description: Specifies whether to retrieve data of Xlogs that have been cut off by redo 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:
- off: disabled.
- on: enabled.
Default value: off
Setting method: This is a SIGHUP parameter. Set it based on instructions provided in Table 1.
Setting suggestion: If you can accept the loss of some data caused by forcible service (system) switchover, set this parameter to on when the service recovery has the highest priority.
backup_open
Parameter description: Specifies whether to enable the DR cluster. After the DR cluster is enabled, the CM runs in DR cluster mode.
Value range: an integer ranging from 0 to 1. Any modification of this parameter takes effect only after CM Server is restarted. This parameter cannot be enabled for non-DR clusters. For details about how to modify this parameter, see Table 2.
- 0: disabled.
- 1: enabled.
Default value: 0
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:
- 1: enabled.
- 0: disabled.
Default value:
Independent deployment: 1
Finance edition (standard), enterprise edition, and finance edition (data computing): 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: Retain the default value. You can adjust the value based on the disk space and scenario requirements.
cluster_starting_aribt_delay
Parameter description: Specifies the time that CM Server waits for the static primary DN to be promoted to primary during cluster startup.
Value range: an integer. The unit is s. The modification of this parameter takes effect after reloading. For details about how to modify the parameter, see Table 2.
Default value: 180
enable_dcf
Parameter description: Specifies the status of the DCF mode.
Value range: Boolean. The modification of this parameter takes effect after reloading. For details about how to modify the parameter, see Table 2.
- 0: disabled.
- 1: enabled.
Default value: off
ddb_type
Parameter description: Specifies whether to switch between ETCD and DCC modes.
Value range: an integer. 0: ETCD; 1: DCC. Any modification of this parameter takes effect only after CM Server is restarted. For details about how to modify this parameter, see Table 2.
Default value: 0
enable_ssl
Parameter description: Specifies whether to enable SSL.
Value range: Boolean. After this function is enabled, the SSL certificate is used to encrypt communication. Any modification of this parameter takes effect only after CM Server is restarted. For details about how to modify this parameter, see Table 2.
Default value:
- on indicates that SSL is enabled.
- off indicates that SSL is disabled.
- Default value: off
To ensure security, you are advised not to disable it. After this function is disabled, the CM does not use encrypted communication and all information is transmitted in plaintext, which may bring security risks such as eavesdropping, tampering, and spoofing.
ssl_cert_expire_alert_threshold
Parameter description: Specifies the SSL certificate expiration alarm time.
Value range: an integer. The unit is day. 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. Any modification of this parameter takes effect only after CM Server is restarted. For details about how to modify this parameter, see Table 2.
Default value: 90
ssl_cert_expire_check_interval
Parameter description: Specifies the period for checking whether the SSL certificate expires.
Value range: an integer. The unit is s. Any modification of this parameter takes effect only after CM Server is restarted. For details about how to modify this parameter, see Table 2.
Default value: 86400
ddb_log_level
Parameter description: Sets the DDB log level.
To disable the log function, set this parameter to "NONE", which cannot be used together with the following log levels:
To enable the log function, set this parameter to one or a combination of the following log levels: RUN_ERR|RUN_WAR|RUN_INF|DEBUG_ERR|DEBUG_WAR|DEBUG_INF|TRACE|PROFILE|OPER. If two or more log levels are used together, separate them with vertical bars (|). The log level cannot be set to an empty string.
Value range: a string containing one or a combination of the following log levels: RUN_ERR|RUN_WAR|RUN_INF|DEBUG_ERR|DEBUG_WAR|DEBUG_INF|TRACE|PROFILE|OPER. The modification of this parameter takes effect after reloading. For details about how to modify the parameter, see Table 2.
Default value: RUN_ERR|RUN_WAR|DEBUG_ERR|OPER|RUN_INF|PROFILE
ddb_log_backup_file_count
Parameter description: Specifies the maximum number of log files that can be saved.
Value range: an integer ranging from 1 to 100. The modification of this parameter takes effect after reloading. For details about how to modify the parameter, see Table 2.
Default value: 10
ddb_max_log_file_size
Parameter description: Specifies the maximum number of bytes in a log.
Value range: a string, in the range [1MB,1000MB]. The modification of this parameter takes effect after reloading. For details about how to modify the parameter, see Table 2.
Default value: 10MB
ddb_log_suppress_enable
Parameter description: Specifies whether to enable the log suppression function.
Value range: an integer. 0: disabled; 1: enabled. The modification of this parameter takes effect after reloading. For details about how to modify the parameter, see Table 2.
Default value: 1
ddb_election_timeout
Parameter description: Specifies the DCC election timeout period.
Value range: an integer, in the range [1,600], in seconds. The modification of this parameter takes effect after reloading. For details about how to modify the parameter, see Table 2.
Default value: 3
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.
Value range: an integer, in the range [0,21474836] (unit: second). The modification of this parameter takes effect after reloading. For details about how to modify the parameter, see Table 2.
Default value: 0
install_type
Parameter description: Specifies the settings related to the DR cluster to distinguish the cluster type.
Value range: an integer ranging from 0 to 2. Any modification of this parameter takes effect only after CM Server is restarted. This parameter cannot be enabled for non-DR clusters. For details about how to modify this parameter, see Table 1.
Default value: 0
- 0 indicates the cluster for which no DR relationship is established.
- 1 indicates a Dorado-based cluster.
- 2 indicates a streaming-based cluster.
enable_synclist_single_inst
Parameter description: Specifies whether to reduce copies to one primary and zero standby.
Parameter type: Boolean.
Unit: none
Value range:
- off: This function is disabled.
- on: This function is enabled.
Default value: off
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.
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