DCF Parameters Settings

enable_dcf

Parameter description: Specifies whether to enable the DCF mode.

Parameter type: Boolean.

Unit: none

Value range:

• on: The current log replication mode is DCF.
• off: The current log replication mode is not DCF.

Default value: off

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

Setting suggestion: To use the DCF log replication mode, set enable_dcf to on.

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

dcf_ssl

Parameter description: This parameter is no longer used. The DCF reuses the GUC parameter ssl. For details, see Security and Authentication.

Parameter type: Boolean.

Unit: none

Value range:

• on: SSL is used.
• off: SSL is not used.

Default value: on

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

Setting suggestion: Retain the default value.

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

dcf_config

Parameter description: Specifies the DCF database instance configuration information, which is configured by the OM during installation and cannot be modified after installation.

Parameter type: string.

Unit: none

Value range: a string.

Default value: configured by the OM during installation.

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

Setting suggestion: This parameter can only be viewed.

Risks and impacts of improper settings: none

dcf_data_path

Parameter description: Specifies the DCF data path, which is configured by the OM during installation and cannot be modified after installation.

Parameter type: string.

Unit: none

Value range: valid path of a directory.

Default value: dcf_data in the DN data directory

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

Setting suggestion: This parameter can only be viewed.

Risks and impacts of improper settings: none

dcf_log_path

Parameter description: Specifies the DCF log path, which is configured by the OM during installation and cannot be modified after installation.

Parameter type: string.

Unit: none

Value range: valid path of a directory.

Default value: dcf_log in the DN data directory

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

Setting suggestion: This parameter can only be viewed.

Risks and impacts of improper settings: none

dcf_node_id

Parameter description: Specifies the ID of the DN where the DCF is located. This parameter is defined by the user during installation and mode switching.

Parameter type: integer.

Unit: none

Value range: 1 to 2147483647

Default value: specified by users during installation.

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

Setting suggestion: Retain the default value.

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

dcf_max_workers

Parameter description: Specifies the largest number of DCF callback function threads. The DCF needs to apply for the shared memory and semaphore before it calls the function registered by the DN with the DCF through the callback function.

Parameter type: integer.

Unit: none

Value range: 0 to 262143

Default value: 40

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

Setting suggestion: Retain the default value.

Risks and impacts of improper settings: If this parameter is set to a large value, resources may be insufficient and the cluster installation may fail.

dcf_truncate_threshold

Parameter description: Specifies the threshold for a DN to truncate DCF logs.

Parameter type: integer.

Unit: none

Value range: 1 to 2147483647

Default value: 100000

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

Setting suggestion: Retain the default value.

Risks and impacts of improper settings: If the threshold is too large, logs may not be truncated for a long time, occupying memory.

dcf_election_timeout

Parameter description: Specifies the timeout interval for selecting the DCF leader and follower. The election timeout interval depends on the status of the network between DNs. If the timeout interval is short and the network quality is poor, timeout occurs. After the network recovers, the election becomes normal. You are advised to set a proper timeout interval based on the current network status. Restriction on the DCF node clock: The maximum clock difference between DCF nodes is less than half of the election timeout interval. In DCF manual election mode, to ensure timely CM election, do not modify this parameter. Instead, use the default election timeout interval.

Parameter type: integer.

Unit: second

Value range: 1 to 600

Default value: 3

Setting method: This is a SIGHUP parameter. Set it based on instructions provided in Table 1. For example, if the value is 60 without a unit, dcf_election_timeout indicates 60s. If the value is 1min, dcf_election_timeout indicates 1 minute. The unit must be second or minute if required.

Setting suggestion: Set a proper timeout interval based on the current network status.

Risks and impacts of improper settings: If the network environment is poor and the timeout period is short, timeout election may occur.

dcf_enable_auto_election_priority

Parameter description: Specifies whether the DCF priority is allowed to be automatically adjusted.

Parameter type: integer.

Unit: none

Value range:

• 0: not allowed.
• 1: allowed.

Default value: 1

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

Setting suggestion: Retain the default value.

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

dcf_election_switch_threshold

Parameter description: Specifies the DCF threshold for preventing frequent switchover to primary. It is recommended that this parameter be set based on the maximum fault duration acceptable for user services.

Parameter type: integer.

Unit: second

Value range: 0 to 2147483647

Default value: 0

Setting method: This is a SIGHUP parameter. Set it based on instructions provided in Table 1. The value cannot contain a unit.

Setting suggestion: Set this parameter based on the maximum fault duration acceptable to services.

Risks and impacts of improper settings: If this parameter is set to a large value, services may be unavailable for a long time.

dcf_run_mode

Parameter description: Specifies the DCF election mode, including the automatic election mode, manual election mode, and disabling the election mode. Currently, the election mode can be disabled only in minority restoration scenarios. If the election mode is disabled, the database instance will become unavailable.

The working mode of an instance can be switched only when the instance is running properly. The DCF working mode configured in GUC parameters must be the same as that configured by using cm_ctl. That is, both DCF working modes must be set to manual or automatic at the same time.

For example, to set the DCF manual mode, run the following command:

cm_ctl set --param --server -k dn_arbitrate_mode=quorum
cm_ctl reload --param --server
gs_guc reload -Z datanode -I all -N all  -c "dcf_run_mode=1"

To set the DCF automatic mode, run the following command:

cm_ctl set --param --server -k dn_arbitrate_mode=paxos
cm_ctl reload --param --server
gs_guc reload -Z datanode -I all -N all  -c "dcf_run_mode=0"

Parameter type: enumerated type

Unit: none

Value range: 0, 1, and 2

• 0: automatic election mode.
• 1: manual election mode.
• 2: disabling the election mode.

Default value: 1

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

Setting suggestion: Retain the default value.

Risks and impacts of improper settings: Currently, disabling the election mode applies only to minority recovery scenarios. If the election mode is disabled, the database instance will be unavailable.

dcf_log_level

Parameter description: Specifies the DCF log level.

Parameter type: string.

Unit: none

Value range:

• 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 character string.

Default value: "RUN_ERR|RUN_WAR|DEBUG_ERR|OPER|RUN_INF|PROFILE"

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

Setting suggestion: Retain the default value.

Risks and impacts of improper settings: If the log level is too low, log information may be missing.

dcf_log_backup_file_count

Parameter description: Specifies the number of DCF run log backups.

Parameter type: integer.

Unit: none

Value range: 1 to 1000

Default value: 100

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

Setting suggestion: Retain the default value.

Risks and impacts of improper settings: If the value is too small, the number of backup files is small and logs are lost.

dcf_max_log_file_size

Parameter description: Specifies the maximum size of a DCF run log file.

Parameter type: integer.

Unit: MB

Value range: 1 to 1000

Default value: 10

Setting method: This is a SIGHUP parameter. Set it based on instructions provided in Table 1. For example, if the value is 10 without a unit, dcf_max_log_file_size indicates 10 MB. If the value is 10MB, dcf_max_log_file_size indicates 10 MB. The unit must be MB if required.

Setting suggestion: Retain the default value.

Risks and impacts of improper settings: If the value is too large, a single log file may be opened and the query efficiency may decrease.

dcf_socket_timeout

Parameter description: Specifies the timeout interval for the DCF communication module to connect to the socket. This parameter takes effect upon the system restart. In an environment where the network quality is poor, if the timeout interval is set to a small value, a connection may fail to be set up. In this case, you need to increase the value.

Parameter type: integer.

Unit: millisecond

Value range: 10 to 600000 (10 minutes)

Default value: 5000

Setting method: This is a POSTMASTER parameter. Set it based on instructions provided in Table 1. For example, if the value is 5000 without a unit, dcf_socket_timeout indicates 5000 ms. If the value is 1min, dcf_socket_timeout indicates 1 minute (that is, 60000 ms). The unit must be millisecond, second, or minute if required.

Setting suggestion: Retain the default value.

Risks and impacts of improper settings: When the network environment is poor, a small timeout period may cause a connection setup failure.

dcf_connect_timeout

Parameter description: Specifies the timeout interval for the DCF communication module to set up a connection. This parameter takes effect upon the system restart. In an environment where the network quality is poor, if the timeout interval is set to a small value, a connection may fail to be set up. In this case, you need to increase the value.

Parameter type: integer.

Unit: millisecond

Value range: 10 to 600000 (10 minutes)

Default value: 60000

Setting method: This is a POSTMASTER parameter. Set it based on instructions provided in Table 1. For example, if the value is 5000 without a unit, dcf_connect_timeout indicates 5000 ms. If the value is 1min, dcf_connect_timeout indicates 1 minute (that is, 60000 ms). The unit must be millisecond, second, or minute if required.

Setting suggestion: Retain the default value.

Risks and impacts of improper settings: When the network environment is poor, a small timeout period may cause a connection setup failure.

dcf_mec_fragment_size

Parameter description: Specifies the fragment size of the DCF communication module. This parameter takes effect upon the system restart.

Parameter type: integer.

Unit: KB

Value range: 32 to 10240

Default value: 64

Setting method: This is a POSTMASTER parameter. Set it based on instructions provided in Table 1. The value cannot contain a unit.

Setting suggestion: Retain the default value.

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

dcf_stg_pool_max_size

Parameter description: Specifies the maximum size of the memory pool of the DCF storage module. This parameter takes effect upon the system restart.

Parameter type: integer.

Unit: MB

Value range: 32 to 2147483647

Default value: 2048

Setting method: This is a POSTMASTER parameter. Set it based on instructions provided in Table 1. For example, if the value is 2048 without a unit, dcf_stg_pool_max_size indicates 2048 MB. If the value is 5GB, dcf_stg_pool_max_size indicates 5 GB (that is, 5120 MB). The unit must be MB or GB if required.

Setting suggestion: Retain the default value.

Risks and impacts of improper settings: If the value is too large, memory resources may be insufficient. If the value is too small, storage module resources may be insufficient.

dcf_stg_pool_init_size

Parameter description: Specifies the minimum size of the memory pool of the DCF storage module. This parameter takes effect upon the system restart.

Parameter type: integer.

Unit: MB

Value range: 32 to 2147483647

Default value: 32

Setting method: This is a POSTMASTER parameter. Set it based on instructions provided in Table 1. For example, if the value is 2048 without a unit, dcf_stg_pool_init_size indicates 2048 MB. If the value is 5GB, dcf_stg_pool_init_size indicates 5 GB (that is, 5120 MB). The unit must be MB or GB if required.

Setting suggestion: Retain the default value.

Risks and impacts of improper settings: If the value is too large, memory resources may be insufficient. If the value is too small, storage module resources may be insufficient.

dcf_mec_pool_max_size

Parameter description: Specifies the maximum size of the memory pool of the DCF communication module. This parameter takes effect upon the system restart.

Parameter type: integer.

Unit: MB

Value range: 32 to 2147483647

Default value: 200

Setting method: This is a POSTMASTER parameter. Set it based on instructions provided in Table 1. For example, if the value is 2048 without a unit, dcf_mec_pool_max_size indicates 2048 MB. If the value is 5GB, dcf_mec_pool_max_size indicates 5 GB (that is, 5120 MB). The unit must be MB or GB if required.

Setting suggestion: Retain the default value.

Risks and impacts of improper settings: If the value is too large, memory resources may be insufficient. If the value is too small, communications module resources may be insufficient.

dcf_flow_control_disk_rawait_threshold

Parameter description: Specifies the disk waiting threshold for DCF flow control.

Parameter type: integer.

Unit: μs

Value range: 0 to 2147483647

Default value: 100000

Setting method: This is a SIGHUP parameter. Set it based on instructions provided in Table 1. The value cannot contain a unit.

Setting suggestion: Retain the default value.

Risks and impacts of improper settings: If this parameter is set to a large value, the performance may deteriorate and the memory usage may increase.

dcf_flow_control_net_queue_message_num_threshold

Parameter description: Specifies the threshold for the number of messages in a network queue for DCF flow control.

Parameter type: integer.

Unit: none

Value range: 0 to 2147483647

Default value: 1024

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

Setting suggestion: Retain the default value.

Risks and impacts of improper settings: If this parameter is set to a small value, the performance may deteriorate severely.

dcf_flow_control_cpu_threshold

Parameter description: Specifies the threshold for DCF CPU flow control.

Parameter type: integer.

Unit: none

Value range: 0 to 2147483647

Default value: 100

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

Setting suggestion: Retain the default value.

Risks and impacts of improper settings: If this parameter is set to a small value, the performance may deteriorate severely.

dcf_mec_batch_size

Parameter description: Specifies the number of batch messages for DCF communication. When the value is 0, the DCF automatically adjusts the value based on the network and the amount of data to be written. This parameter takes effect upon the system restart.

Parameter type: integer.

Unit: none

Value range: 0 to 1024

Default value: 0

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

Setting suggestion: Retain the default value.

Risks and impacts of improper settings: If this parameter is set to a small value, the communications efficiency between nodes decreases.

dcf_mem_pool_max_size

Parameter description: Specifies the maximum DCF memory. This parameter takes effect upon the system restart.

Parameter type: integer.

Unit: MB

Value range: 32 to 2147483647

Default value: 2048

Setting method: This is a POSTMASTER parameter. Set it based on instructions provided in Table 1. For example, if the value is 2048 without a unit, dcf_mem_pool_max_size indicates 2048 MB. If the value is 5GB, dcf_mem_pool_max_size indicates 5 GB (that is, 5120 MB). The unit must be MB or GB if required.

Setting suggestion: Retain the default value.

Risks and impacts of improper settings: If this parameter is set to a small value, the cluster installation will fail.

dcf_mem_pool_init_size

Parameter description: Specifies the initial size of the DCF memory. This parameter takes effect upon the system restart.

Parameter type: integer.

Unit: MB

Value range: 32 to 2147483647

Default value: 32

Setting method: This is a POSTMASTER parameter. Set it based on instructions provided in Table 1. For example, if the value is 2048 without a unit, dcf_mem_pool_init_size indicates 2048 MB. If the value is 5GB, dcf_mem_pool_init_size indicates 5 GB (that is, 5120 MB). The unit must be MB or GB if required.

Setting suggestion: Retain the default value.

Risks and impacts of improper settings: If this parameter is set to a small value, the cluster installation will fail.

dcf_compress_algorithm

Parameter description: Specifies the compression algorithm for DCF run log transmission.

Parameter type: integer.

Unit: none

Value range:

• 0: no compression.
• 1: LZ4 compression algorithm.

Default value: 0

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

Setting suggestion: To enable the LZ4 compression algorithm, set dcf_compress_algorithm to 1.

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

dcf_compress_level

Parameter description: Specifies the compression level for DCF log transmission. Before this parameter takes effect, a valid compression algorithm must be configured, that is, the dcf_compress_algorithm parameter is set.

Parameter type: integer.

Unit: none

Value range: 1 to 22. If compression is disabled, the configured compression level does not take effect.

Default value: 1

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

Setting suggestion: Retain the default value.

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

dcf_mec_channel_num

Parameter description: Specifies the number of DCF communication channels. This parameter takes effect upon the system restart.

Parameter type: integer.

Unit: none

Value range: 1 to 64

Default value: 1

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

Setting suggestion: Retain the default value.

Risks and impacts of improper settings: If this parameter is set to a small value, the communications efficiency between nodes may decrease.

dcf_rep_append_thread_num

Parameter description: Specifies the number of DCF log replication threads. This parameter takes effect upon the system restart.

Parameter type: integer.

Unit: none

Value range: 1 to 1000

Default value: 2

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

Setting suggestion: Retain the default value.

Risks and impacts of improper settings: If this parameter is set to a large value, threads may be idle and the resource usage may decrease.

dcf_mec_agent_thread_num

Parameter description: Specifies the number of DCF communication working threads. This parameter takes effect upon the system restart. It is recommended that the value of dcf_mec_agent_thread_num be greater than or equal to 2 x Number of nodes x Value of dcf_mec_channel_num.

Parameter type: integer.

Unit: none

Value range: 1 to 1000

Default value: 10

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

Setting suggestion: It is recommended that the value be greater than or equal to 2 x Number of nodes x dcf_mec_channel_num.

Risks and impacts of improper settings: If this parameter is set to a large value, threads may be idle and the resource usage may decrease.

dcf_mec_reactor_thread_num

Parameter description: Specifies the number of reactor threads used by the DCF. This parameter takes effect upon the system restart. It is recommended that the ratio of the value of dcf_mec_reactor_thread_num to the value of dcf_mec_agent_thread_num be 1:40.

Parameter type: integer.

Unit: none

Value range: 1 to 100

Default value: 1

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

Setting suggestion: It is recommended that the ratio of the value of dcf_mec_reactor_thread_num to the value of dcf_mec_agent_thread_num be 1:40.

Risks and impacts of improper settings: If this parameter is set to a large value, threads may be idle and the resource usage may decrease.

dcf_log_file_permission

Parameter description: Specifies the attribute of the DCF run log file. The parameter setting takes effect after the system is restarted. This parameter is configured during installation and cannot be modified. To allow other users in the same group to access logs, ensure that all parent directories can be accessed by other users in the same group. That is, if dcf_log_path_permission is set to 750, dcf_log_file_permission can only be set to 600 or 640. If dcf_log_path_permission is set to 700, dcf_log_file_permission must be set to 600.

Parameter type: enumerated type.

Unit: none

Value range: 600 and 640

Default value: 600

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

Setting suggestion: The permission of dcf_log_path_permission must be higher than that of dcf_log_file_permission.

Risks and impacts of improper settings: Improper settings may cause user access failures.

dcf_log_path_permission

Parameter description: Specifies the attribute of the DCF run log directory. The parameter setting takes effect after the system is restarted. This parameter is configured during installation and cannot be modified. To allow other users in the same group to access the log path, set this parameter to 750. Otherwise, set this parameter to 700.

Parameter type: enumerated type.

Unit: none

Value range: 700 and 750

Default value: 700

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

Setting suggestion: To allow other users in the same group to access the log path, set this parameter to 750. Otherwise, set this parameter to 700.

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

dcf_majority_groups

Parameter description: Sets the DCF policy-based majority function. For a group that requires this parameter, at least one standby node in the group receives logs. That is, there is a synchronous standby node in the group. If nodes are added to or deleted from the DCF instance or the group value of a node in the instance is changed, you need to modify the configuration accordingly. When modifying this parameter, ensure that the value of group exists and is valid.

Parameter type: string.

Unit: none

Value range:

• To disable the policy-based majority function, enter an empty string "".
• To enable the function, configure valid group values separated by commas (,). The group values must exist in dcf_config. For example, if the group values 1 and 2 are added to the DCF policy-based majority configuration, you can set this parameter to "1,2". If the group value does not exist in dcf_config or other characters are configured, the DCF considers the configured group invalid.

Default value: ""

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

Setting suggestion: Retain the default value.

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

If all nodes in a group are faulty after the parameter is configured, you need to remove the group from the parameter list when performing node build operations (node recovery or node replacement without changing the IP address) on a node. After the node recovers, you can configure the group again.

dcf_node_id_map

Parameter description: Specifies the dictionary mapping between standby DN names and DCF node IDs. The parameter setting takes effect after the system is restarted. This parameter is configured during installation and cannot be modified. This parameter is used in DCF database instance installation, upgrade, and node replacement scenarios. The value of standby_name configured in the GUC parameter synchronous_standby_names must be included in this dictionary.

Parameter type: string.

Unit: none

Value range: The setting format is 'standby_name1:dcf_node_id1,standby_name2:dcf_node_id2'. The values of standby DN names and the corresponding DCF node IDs are separated by commas (,).

Default value: ""

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

Setting suggestion: Retain the default value.

Risks and impacts of improper settings: Improper settings may cause cluster installation and upgrade failures.

dcf_candidate_names

Parameter description: Specifies the DCF candidate list. That is, names of DNs that may be selected as the primary node. In DCF automatic mode, the election policy is controlled by this parameter. DNs not in the list cannot be elected as a primary node.

Parameter type: string.

Unit: none

Value range: a value in the format of 'dn_name1,dn_name2,dn_name3'. The parameter depends on dcf_node_id_map. DN names must be in dcf_node_id_map and separated by commas (,).

Default value: ""

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

Setting suggestion: Retain the default value.

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

dcf_thread_effective_time

Parameter description: Specifies the effective time of the DCF flushing thread. This parameter is used to determine whether the disk I/O hangs. If the DCF control log cannot update and I/O resources cannot be accessed within the period specified by this parameter, the DCF considers that the thread I/O hangs and the switchover is triggered. If this parameter is set to 0, the I/O hang detection is disabled.

Parameter type: integer.

Unit: second

Value range: 0 to 1000

Default value: 160

Setting method: This is a SIGHUP parameter. Set it based on instructions provided in Table 1. The value cannot contain a unit.

Setting suggestion: Retain the default value.

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

dcf_pri_leader_timeout

Parameter description: Specifies the timeout interval for priority-based leader election. In DCF automatic mode, after priority-based leader election is enabled, the backup node triggers priority-based leader election. If the backup node is not elected as the leader within the timeout interval, the election is canceled. If this parameter is set to 0, the priority-based selection of the primary node waits until the election is successful.

Parameter type: integer.

Unit: second

Value range: 0 to 3600

Default value: 60

Setting method: This is a SIGHUP parameter. Set it based on instructions provided in Table 1. The value cannot contain a unit.

Setting suggestion: Retain the default value.

Risks and impacts of improper settings: If this parameter is set to a large value, the cluster may be in the no-primary state for a long time.

dcf_static_leader_timeout

Parameter description: Specifies the timeout interval for preferentially electing the old leader. In DCF automatic mode, after the database instance is restarted, the old leader is preferentially elected. If the election fails within the timeout interval, the election is canceled.

Parameter type: integer.

Unit: second

Value range: 0 to 600

Default value: 60

Setting method: This is a POSTMASTER parameter. Set it based on instructions provided in Table 1. The value cannot contain a unit.

Setting suggestion: Retain the default value.

Risks and impacts of improper settings: If this parameter is set to a large value, the cluster may be in the no-primary state for a long time.