CM Server Parameters

log_dir

Parameter description: Specifies the directory where CM Server logs are stored. The value can be an absolute path, or 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 the 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: 16 MB

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 CM Server thread pool. If the value 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.

Value range: an integer ranging from 2 to 1000. Any modification of this parameter takes effect only after CM Server is restarted. For details about how to modify the parameter, see Table 2.

Default value: 1000

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 the system_alarm log. In this case, the value of alarm_component is /opt/huawei/snas/bin/snas_cm_cmd.
• If --alarm-type in the gs_preinstall script is set to 1, a third-party component is connected. In this case, the value of alarm_component is the absolute path of the executable program of the third-party component.

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

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. When adjusting this parameter, you are advised to adjust the max_size_for_xlog_retention parameter of the DN to prevent the cluster read-only threshold from being triggered by backup operations.

Value range: an integer ranging from 1 to 99, in percentage. The modification of this parameter takes effect after reloading. For details about how to modify the parameter, see Table 2.

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. 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. 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 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, cm_krb_server_keyfile 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 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 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.

Value range: Boolean. The modification of this parameter takes effect after reloading. For details about how to modify the parameter, see Table 2.

• off: disabled.
• on: enabled.

Default value: off

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 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 time are shortened. The CM can reach the E2E RTO indicator (RTO for a single instance ≤ 10s; RTO for combined faults ≤ 30s).

Value range: 0 or 1. The value 1 indicates enabled, while the value 0 indicates disabled. The modification of this parameter takes effect after reloading. For details about how to modify the parameter, see Table 2.

Default value:

Independent deployment: 1

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 the 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 the 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 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 alerting 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 the 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 the 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 [1 MB, 1000 MB]. The modification of this parameter takes effect after reloading. For details about how to modify the parameter, see Table 2.

Default value: 10 MB

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 the 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.

Value range: Boolean. If this function is enabled, the copies are reduced to one primary and zero standby. If this parameter is incorrectly set, the default value is used. The modification of this parameter takes effect after reloading. For details about how to modify parameters, see the Set cm parameter table in section "Unified Database Management Tool > cm_ctl Tool Introduction" in Tool Reference.

• off: indicates that this function is disabled.
• on: indicates that this function is enabled.

Default value: off