CM Parameters

You can view cm_agent parameters in the cm_agent.conf file in the cm_agent data directory and cm_server parameters in the cm_server.conf file in the cm_server data directory.

Parameters Related to cm_agent

log_dir

Parameter description: Specifies the directory where cm_agent logs are stored. It can be specified as an absolute path, or a path relative to $GAUSSLOG. When you set an absolute path using cm_ctl, the path must be included in quotation marks, for example, cm_ctl set –param –agent -k log_dir=“'/log/dir'”.

Value range: a string with up to 1024 characters. Any modification of this parameter takes effect only after cm_agent is restarted. For details about how to modify the parameter, see Parameters for set cm.

Default value: log, indicating that the cm_agent logs are generated in the CM directory in $GAUSSLOG.

log_file_size

Parameter description: Specifies the size of a log file. If the size of the cm_agent-xx-current.log file exceeds the specified size, a new log file is created to record log information.

Value range: an integer, in the range [0,2047]. The actual value range is [1,2047]. The unit is MB. Any modification of this parameter takes effect only after cm_agent is restarted. For details about how to modify the parameter, see Parameters for set cm.

Default value: 16 MB

log_min_messages

Parameter description: Specifies which message levels are written to the cm_agent log. A higher level covers the messages of all the lower levels. The lower the level is, the fewer messages will be written into the log.

Value range: enumerated type. Valid values are debug5, debug1, warning, error, log, and fatal (case-insensitive). Any modification of this parameter takes effect only after cm_agent is restarted. For details about how to modify the parameter, see Parameters for set cm.

Default value: warning

incremental_build

Parameter description: Specifies whether a standby node is incrementally built. If this parameter is enabled, a standby node is incrementally rebuilt. Otherwise, a standby node is fully rebuilt.

Value range: Boolean. Any modification of this parameter takes effect only after cm_agent is restarted. For details about how to modify the parameter, see Parameters for set cm.

• on, yes, true, or 1: A standby node is incrementally rebuilt.
• off, no, false, or 0: A standby node is fully rebuilt.

Default value: on

security_mode

Parameter description: Specifies whether nodes are started in secure mode. If this parameter is enabled, nodes are started in secure mode. Otherwise, nodes are started in non-secure mode.

Value range: Boolean. The modification of this parameter takes effect dynamically. For details about how to modify the parameter, see Parameters for set cm.

• on, yes, true, or 1: Nodes are started in secure mode.
• off, no, false, or 0: Nodes are started in non-secure mode.

Default value: off

upgrade_from

Parameter description: Specifies the internal version number of the database before an in-place upgrade. Do not modify the value of this parameter.

Value range: a non-negative integer, in the range [0,4294967295]. Any modification of this parameter takes effect only after cm_agent is restarted. For details about how to modify the parameter, see Parameters for set cm.

Default value: 0

alarm_component

Parameter description: Specifies the position of the alarm component that handles alarms if the first mode is used. When you set an absolute path using cm_ctl, the path must be included in quotation marks (””), for example, cm_ctl set –param –agent -k alarm_component=“'/alarm/dir'”.

Value range: a string with up to 1024 characters. Any modification of this parameter takes effect only after cm_agent is restarted. For details about how to modify the parameter, see Parameters for set cm.

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

alarm_report_interval

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

Value range: a non-negative integer, in the range [0,2147483647] (unit: second). The modification of this parameter takes effect after reloading. For details about how to modify the parameter, see Parameters for set cm.

Default value: 1

agent_heartbeat_timeout

Parameter description: Specifies the time to wait before the cm_server heartbeat times out.

Value range: an integer, in the range [2,2147483647] (unit: second). Any modification of this parameter takes effect only after cm_agent is restarted. For details about how to modify the parameter, see Parameters for set cm.

Default value: 5

agent_connect_timeout

Parameter description: Specifies the time to wait before the attempt of cm_agent to connect to cm_server times out.

Value range: an integer, in the range [0,2147483647] (unit: second). Any modification of this parameter takes effect only after cm_agent is restarted. For details about how to modify the parameter, see Parameters for set cm.

Default value: 1

agent_connect_retries

Parameter description: Specifies the number of times cm_agent tries to connect to cm_server.

Value range: an integer, in the range [0,2147483647]. Any modification of this parameter takes effect only after cm_agent is restarted. For details about how to modify the parameter, see Parameters for set cm.

Default value: 15

agent_kill_instance_timeout

Parameter description: Specifies the interval from the time when cm_agent fails to connect to the primary cm_server to the time when cm_agent kills all instances on the node.

Value range: an integer, in the range [0,2147483647]. Any modification of this parameter takes effect only after cm_agent is restarted. For details about how to modify the parameter, see Parameters for set cm.

Default value: 0, indicating that the operation of killing all instances on the node is not initiated.

agent_report_interval

Parameter description: Specifies the interval at which cm_agent reports the instance status.

Value range: an integer, in the range [0,2147483647] (unit: second). Any modification of this parameter takes effect only after cm_agent is restarted. For details about how to modify the parameter, see Parameters for set cm.

Default value: 1

alarm_report_max_count

Parameter description: Specifies the maximum number of times an alarm is reported.

Value range: a non-negative integer, in the range [1,2592000]. The modification of this parameter takes effect after reloading. For details about how to modify the parameter, see Parameters for set cm.

Default value: 1

agent_check_interval

Parameter description: Specifies the interval at which cm_agent queries the status of instances.

Value range: an integer, in the range [0,2147483647] (unit: second). Any modification of this parameter takes effect only after cm_agent is restarted. For details about how to modify the parameter, see Parameters for set cm.

Default value: 2

enable_log_compress

Parameter description: Specifies whether to enable log compression.

Value range: Boolean. Any modification of this parameter takes effect only after cm_agent is restarted. For details about how to modify the parameter, see Parameters for set cm.

• on, yes, true, or 1: Log compression is allowed.
• off, no, false, or 0:Log compression is not allowed.

Default value: on

process_cpu_affinity

Parameter description: Specifies whether to bind a primary node process to a CPU core before starting the process. If this parameter is set to 0, core binding is not performed. If it is set to another value, core binding is performed, and the number of physical CPU cores is 2n. Restart the database and cm_agent for any modification of this parameter to take effect. Only ARM is supported. For details about how to modify the parameter, see Parameters for set cm.

Value range: an integer, in the range [0,2].

Default value: 0

enable_xc_maintenance_mode

Parameter description: Specifies whether the pgxc_node system catalog can be modified when the database is in read-only mode.

Value range: Boolean. The modification of this parameter takes effect after reloading. For details about how to modify the parameter, see Parameters for set cm.

• on, yes, true, or 1: The function of modifying the pgxc_node system catalog is enabled.
• off, no, false, or 0: The function of modifying the pgxc_node system catalog is disabled.

Default value: on

log_threshold_check_interval

Parameter description: Specifies the interval for compressing and clearing CM logs. The logs are compressed and cleared every 1800 seconds.

Application scope: $GAUSSLOG**/cm/cm_ctl**, $GAUSSLOG**/cm/cm_server**, files in the $GAUSSLOG**/cm/om_monitor** directory and log files prefixed with cm_agent-, system_call-, and system_alarm- in the $GAUSSLOG**/cm/cm_agent** directory

Value range: an integer, in the range [0,2147483647] (unit: second). Any modification of this parameter takes effect only after cm_agent is restarted. For details about how to modify the parameter, see Parameters for set cm.

Default value: 1800

log_max_size

Parameter description: Specifies the maximum size of CM logs. When the total size of CM logs exceeds (value of log_max_size x 95⁄100) MB, historical compressed logs are deleted in sequence based on the log generation time until the total size is less than (value of log_max_size x 95⁄100) MB.

Application scope: $GAUSSLOG**/cm/cm_ctl**, $GAUSSLOG**/cm/cm_server**, files in the $GAUSSLOG**/cm/om_monitor** directory and log files prefixed with cm_agent-, system_call-, and system_alarm- in the $GAUSSLOG**/cm/cm_agent** directory

Value range: an integer, in the range [0,2147483647] (unit: MB). Any modification of this parameter takes effect only after cm_agent is restarted. For details about how to modify the parameter, see Parameters for set cm.

Default value: 10240

log_max_count

Parameter description: Specifies the maximum number of CM log files that can be stored. When the total number of CM log files exceeds the value of this parameter, compressed logs that have been stored for days longer than those specified by log_saved_days are deleted based on the name of the compressed log file.

Application scope: $GAUSSLOG**/cm/cm_ctl**, $GAUSSLOG**/cm/cm_server**, files in the $GAUSSLOG**/cm/om_monitor** directory and log files prefixed with cm_agent-, system_call-, and system_alarm- in the $GAUSSLOG**/cm/cm_agent** directory

Value range: an integer, in the range [0,10000]. Any modification of this parameter takes effect only after cm_agent is restarted. For details about how to modify the parameter, see Parameters for set cm.

Default value: 10000

log_saved_days

Parameter description: Specifies the number of days for storing compressed CM log files. If the number of compressed CM log files exceeds the value of this parameter and the total number of CM log files exceeds the value of log_max_count, the compressed log files are deleted.

Application scope: $GAUSSLOG**/cm/cm_ctl**, $GAUSSLOG**/cm/cm_server**, files in the $GAUSSLOG**/cm/om_monitor** directory and log files prefixed with cm_agent-, system_call-, and system_alarm- in the $GAUSSLOG**/cm/cm_agent** directory

Value range: an integer, in the range [0,1000]. (unit: day). Any modification of this parameter takes effect only after cm_agent is restarted. For details about how to modify the parameter, see Parameters for set cm.

Default value: 90

agent_phony_dead_check_interval

Parameter description: Specifies the interval at which cm_agent checks whether a process is suspended.

Value range: an integer, in the range [0,2147483647] (unit: second). Any modification of this parameter takes effect only after cm_agent is restarted. For details about how to modify the parameter, see Parameters for set cm.

Default value: 10

unix_socket_directory

Parameter description: Specifies the directory location of the Unix socket. When you set an absolute path using cm_ctl, the path must be included in quotation marks (””), for example, cm_ctl set –param –agent -k unix_socket_directory=“'/unix/dir'”.

Value range: a string with up to 1024 characters. Any modification of this parameter takes effect only after cm_agent is restarted. For details about how to modify the parameter, see Parameters for set cm.

Default value: “

dilatation_shard_count_for_disk_capacity_alarm

Parameter description: Specifies the number of shards to be added in the scale-out scenario. This parameter is used to calculate the threshold for reporting a disk capacity alarm.

Value range: an integer, in the range [0,2147483647]. If this parameter is set to 0, the disk scale-out alarm is not reported. If this parameter is set to a value greater than 0, the disk scale-out alarm is reported and the threshold is calculated based on the number of shards specified by this parameter. Any modification of this parameter takes effect only after cm_agent is restarted. For details about how to modify the parameter, see Parameters for set cm.

Default value: 1

enable_dcf

Parameter description: Specifies the status of the DCF mode.

Value range: Boolean. Any modification of this parameter takes effect only after cm_agent is restarted. For details about how to modify the parameter, see Parameters for set cm.

• on, yes, true, or 1: The DCF function is enabled.
• off, no, false, or 0:The DCF function is disabled.

Default value: off

disaster_recovery_type

Parameter description: Specifies the type of the DR relationship between primary and standby databases.

Value range: an integer, in the range [0,2]. Any modification of this parameter takes effect only after cm_agent is restarted. For details about how to modify the parameter, see Parameters for set cm.

• 0 indicates that no DR relationship is established.
• 1 indicates that the OBS DR relationship is established.
• 2 indicates that the streaming DR relationship is established.

Default value: 0

agent_backup_open

Parameter description: Specifies whether to enable the DR mode. After the DR mode is enabled, the CM runs in DR mode.

Value range: an integer, in the range [0,2]. Any modification of this parameter takes effect only after cm_agent is restarted. For details about how to modify the parameter, see Parameters for set cm.

• 0 indicates that no DR relationship is established.
• 1 indicates that the OBS DR relationship is established (not supported later versions).
• 2 indicates that the streaming DR relationship is established.

Default value: 0

Parameters Related to cm_server

log_dir

Parameter description: Specifies the directory where cm_server logs are stored. It can be specified as an absolute path, or a path relative to $GAUSSLOG. When you set an absolute path using cm_ctl, the path must be included in quotation marks, for example, cm_ctl set –param –server -k log_dir=“'/log/dir'”.

Value range: a string with up to 1024 characters. Any modification of this parameter takes effect only after cm_server is restarted. For details about how to modify the parameter, see Parameters for set cm.

Default value: log, indicating that the cm_server logs are generated in the CM directory in $GAUSSLOG.

log_file_size

Parameter description: Specifies the size of a log file. If the size of the cm_server-xx-current.log file exceeds the specified size, a new log file is created to record log information.

Value range: an integer, in the range [0,2047]. The actual value range is [1,2047]. The unit is MB. Any modification of this parameter takes effect only after cm_server is restarted. For details about how to modify the parameter, see Parameters for set cm.

Default value: 16 MB

log_min_messages

Parameter description: Specifies the message levels to be written to the cm_server log. A higher level covers the messages of all the lower levels. 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 (case-insensitive). Any modification of this parameter takes effect only after cm_server is restarted. For details about how to modify the parameter, see Parameters for set cm.

Default value: warning

thread_count

Parameter description: Specifies the number of threads in the cm_server thread pool.

Value range: an integer, in the range [2,1000]. Any modification of this parameter takes effect only after cm_server is restarted. For details about how to modify the parameter, see Parameters for set cm.

Default value: 1000

instance_heartbeat_timeout

Parameter description: Specifies the time to wait before the instance heartbeat times out.

Value range: an integer, in the range [1,2147483647] (unit: second). Any modification of this parameter takes effect only after cm_server is restarted. For details about how to modify the parameter, see Parameters for set cm.

Default value: 6

instance_failover_delay_timeout

Parameter description: Specifies the delay in cm_server failover after the primary cm_server breakdown is detected.

Value range: an integer, in the range [0,2147483647] (unit: second). Any modification of this parameter takes effect only after cm_server is restarted. For details about how to modify the parameter, see Parameters for set cm.

Default value: 0

cmserver_ha_connect_timeout

Parameter description: Specifies the time to wait before the connection between the primary cm_server and standby cm_server times out.

Value range: an integer, in the range [0,2147483647] (unit: second). Any modification of this parameter takes effect only after cm_server is restarted. For details about how to modify the parameter, see Parameters for set cm.

Default value: 2

cmserver_ha_heartbeat_timeout

Parameter description: Specifies the time to wait before the heartbeat between the primary cm_server and standby cm_server times out.

Value range: an integer, in the range [1,2147483647] (unit: second). Any modification of this parameter takes effect only after cm_server is restarted. For details about how to modify the parameter, see Parameters for set cm.

Default value: 6

cmserver_ha_status_interval

Parameter description: Specifies the interval between synchronizations of primary cm_server and standby cm_server status.

Value range: an integer, in the range [1,2147483647] (unit: second). Any modification of this parameter takes effect only after cm_server is restarted. For details about how to modify the parameter, see Parameters for set cm.

Default value: 1

cmserver_self_vote_timeout

Parameter description: Specifies the timeout interval for cm_server to vote for each other. This parameter is a legacy parameter and does not take effect.

Value range: an integer, in the range [0,2147483647] (unit: second). The modification of this parameter takes effect after reloading. For details about how to modify the parameter, see Parameters for set cm.

Default value: 6

phony_dead_effective_time

Parameter description: Specifies the maximum number of times a database node is detected as a zombie. If the number of times the node is detected as a zombie is greater than the specified value, a process on the node is considered to be a zombie and will be restarted.

Value range: an integer, in the range [1,2147483647]. Any modification of this parameter takes effect only after cm_server is restarted. For details about how to modify the parameter, see Parameters for set cm.

Default value: 5

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, in the range [0,2147483647] (unit: second). Any modification of this parameter takes effect only after cm_server is restarted. For details about how to modify the parameter, see Parameters for set cm.

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, in the range [0,2147483647] (unit: second). Any modification of this parameter takes effect only after cm_server is restarted. For details about how to modify the parameter, see Parameters for set cm.

Default value: 3

alarm_component

Parameter description: Specifies the position of the alarm component that handles alarms if the first mode is used. For details about how to modify the parameter, see Parameters for set cm. When you set an absolute path using cm_ctl, the path must be included in quotation marks (””), for example, cm_ctl set –param –server -k alarm_component=“'/alarm/dir'”.

Value range: a string with up to 1024 characters. Any modification of this parameter takes effect only after cm_server is restarted.

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

alarm_report_interval

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

Value range: a non-negative integer, in the range [0,2147483647] (unit: second). The modification of this parameter takes effect after reloading. For details about how to modify the parameter, see Parameters for set cm.

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, in the range [1,2592000]. The modification of this parameter takes effect after reloading. For details about how to modify the parameter, see Parameters for set cm.

Default value: 1

instance_keep_heartbeat_timeout

Parameter description: cm_agent periodically checks the instance status and reports the status to 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, cm_server delivers a command to cm_agent to restart the instance.

Value range: an integer, in the range [0,2147483647] (unit: second). The modification of this parameter takes effect after reloading. For details about how to modify the parameter, see Parameters for set cm.

Default value: 40

az_switchover_threshold

Parameter description: If the failure rate of a node shard in an AZ (Number of faulty node shards/Total number of node shards x 100%) exceeds the specified value, automatic AZ switchover is triggered.

Value range: an integer, in the range [1,100]. The modification of this parameter takes effect after reloading. For details about how to modify the parameter, see Parameters for set cm.

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, in the range [1,2147483647] (unit: second). The modification of this parameter takes effect after reloading. For details about how to modify the parameter, see Parameters for set cm.

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, in the range [1,2147483647] (unit: second). The modification of this parameter takes effect after reloading. For details about how to modify the parameter, see Parameters for set cm.

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, in the range [1,2147483647] (unit: second). The modification of this parameter takes effect after reloading. For details about how to modify the parameter, see Parameters for set cm.

Default value: 150

cmserver_demote_delay_on_etcd_fault

Parameter description: Specifies the interval at which cm_server is demoted to standby due to unhealthy ETCD.

Value range: an integer, in the range [1,2147483647] (unit: second). The modification of this parameter takes effect after reloading. For details about how to modify the parameter, see Parameters for set cm.

Default value: 8

instance_phony_dead_restart_interval

Parameter description: Specifies the interval at which cm_agent restarts and kills a zombie database instance. The interval between two consecutive kill operations cannot be less than the value of this parameter. Otherwise, cm_agent does not deliver commands.

Value range: an integer, in the range [1800,2147483647] (unit: second). The modification of this parameter takes effect after reloading. For details about how to modify the parameter, see Parameters for set cm.

Default value: 21600

enable_transaction_read_only

Parameter description: Specifies whether a database is in read-only mode.

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 Parameters for set cm.

Default value: off

datastorage_threshold_check_interval

Parameter description: Specifies the interval for checking the disk usage. This interval is specified by the user.

Value range: an integer, in the range [1,2592000] (unit: second). The modification of this parameter takes effect after reloading. For details about how to modify the parameter, see Parameters for set cm.

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.

Value range: an integer, in the range [1,99]. The modification of this parameter takes effect after reloading. For details about how to modify the parameter, see Parameters for set cm.

Default value: 85

max_datastorage_threshold_check

Parameter description: Specifies the maximum interval for checking the disk usage. After you modify the enable_transaction_read_only parameter, the system automatically checks whether the disk usage reaches the threshold at the specified interval.

Value range: an integer, in the range [1,2592000] (unit: second). The modification of this parameter takes effect after reloading. For details about how to modify the parameter, see Parameters for set cm.

Default value: 43200

enable_az_auto_switchover

Parameter description: Specifies whether to enable automatic AZ switchover. If this parameter is set to 1, cm_server automatically switches over services among AZs. Otherwise, when a node 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. The value 0 indicates that automatic AZ switchover is disabled, and the value 1 indicates that automatic AZ switchover is enabled. The modification of this parameter takes effect after reloading. For details about how to modify the parameter, see Parameters for set cm.

Default value: 1

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 the file extension is 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 value of the cm_auth_method parameter is changed to gss, cm_krb_server_keyfile must also be set to the corresponding path correctly. Otherwise, the cluster status will be affected. When you set an absolute path using cm_ctl, the path must be included in quotation marks (””), for example, cm_ctl set –param –server -k cm_krb_server_keyfile=“'/krb/dir'”.

Value range: a string. Any modification of this parameter takes effect only after cm_server is restarted. For details about how to modify the parameter, see Parameters for set cm.

Default value: ${GAUSSHOME}/kerberos/{Username}.keytab. The default value does not take effect and is used only for reference.

switch_rto

Parameter description: Specifies the delay for the forcible startup of cm_server. When force_promote is set to 1 and a shard in the cluster does not have primary cm_server, the system starts timing. After the delay, the forcible startup logic starts to be executed.

Value range: an integer, in the range [60,2147483647] (unit: second). Any modification of this parameter takes effect only after cm_server is restarted. For details about how to modify the parameter, see Parameters for set cm.

Default value: 600

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 data loss). The value 0 indicates that forcible startup is disabled, and the value 1 indicates that forcible startup is enabled.

Value range: an integer, 0 or 1. Any modification of this parameter takes effect only after cm_server is restarted. For details about how to modify the parameter, see Parameters for set cm.

Default value: 0

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, 0 or 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 the parameter, see Parameters for set cm.

• 0: The DR cluster is disabled.
• 1: The DR cluster is enabled.

Default value: 0

enable_dcf

Parameter description: Specifies the status of the DCF mode.

Value range: Boolean. Any modification of this parameter takes effect only after cm_server is restarted. For details about how to modify the parameter, see Parameters for set cm.

• on, yes, true, or 1: The DCF function is enabled.
• off, no, false, or 0: The DCF function is disabled.

Default value: off

ddb_type

Parameter description: Specifies whether to switch between ETCD and DCC modes.

Value range: an integer. 0: specifies the ETCD mode; 1: specifies the DCC mode. Any modification of this parameter takes effect only after cm_server is restarted. For details about how to modify the parameter, see Parameters for set cm.

Default value: 1

NOTE: (MogDB supports only the DCC mode.)

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 the parameter, see Parameters for set cm.

Default value:

• on, yes, true, or 1: SSL is enabled.

• off, no, false, or 0: SSL is disabled.

• Default value: off

  NOTICE: To ensure security, you are not advised 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, in the range [7,180] (unit: 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. The modification of this parameter takes effect after reloading. For details about how to modify the parameter, see Parameters for set cm.

Default value: 90

ssl_cert_expire_check_interval

Parameter description: Specifies the period for checking whether the SSL certificate expires.

Value range: an integer, in the range [0,2147483647] (unit: second). The modification of this parameter takes effect after reloading. For details about how to modify the parameter, see Parameters for set cm.

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 Parameters for set cm.

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, in the range [1,100]. The modification of this parameter takes effect after reloading. For details about how to modify the parameter, see Parameters for set cm.

Default value: 10

ddb_max_log_file_size

Parameter description: Specifies the maximum number of bytes in a log.

Value range: a string with up to 1024 characters, in the range [1 MB,1000 MB]. The modification of this parameter takes effect after reloading. For details about how to modify the parameter, see Parameters for set cm.

Default value: 10M

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 Parameters for set cm.

Default value: 1

ddb_election_timeout

Parameter description: Specifies the DCC election timeout period.

Value range: an integer, in the range [1,600] (unit: second). The modification of this parameter takes effect after reloading. For details about how to modify the parameter, see Parameters for set cm.

Default value: 3

delay_arbitrate_timeout

Parameter description: Specifies the time for waiting for the redo log replay of a node in the same AZ as the primary DN. The node in the same AZ as the primary DN is preferentially promoted to primary.

Value range: an integer, in the range [0,2147483647] (unit: second). For details about how to modify the parameter, see Parameters for set cm.

Default value: 0

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 database status.

Value range: gss or trust. Any modification of this parameter takes effect only after cm_server is restarted. For details about how to modify the parameter, see Parameters for set cm.

Default value: trust

dn_arbitrate_mode

Parameter description: Specifies the DN arbitration mode.

Value range: a string. The modification of this parameter takes effect after reloading. For details about how to modify parameters, see Parameters for set cm. In share_disk mode, you are not advised to change the arbitration mode.

• quorum
• paxos
• share_disk

Default value: quorum