obcdc parameters|V4.3.5|OceanBase Database| docs|Distributed Database

For boolean parameters, 0 indicates False and 1 indicates True.

Cluster configuration

Metadata configuration

Parameter	Meaning	Default Value	Dynamic Change Allowed	Remarks
init_log_level	Startup log level	ALL.*:INFO;SHARE.SCHEMA:INFO	No	The log level during startup, primarily used to output more detailed logs. It will be adjusted to the configuration of `log_level` after startup.
log_level	Log Level After Startup	ALL.*:INFO;SHARE.SCHEMA:WARN	Yes	None
max_log_file_count	Maximum Number of Log Files	0	No	The value range is greater than or equal to 0. A value of 0 indicates no log limit. To reduce the number of log files, you must restart obcdc.
enable_log_limit	Whether to enable log throttling	1	Yes	1: Enable; 0: Disable
rootserver_list	Specify the server information where the root service resides during startup.	`\|`(English half-width)	Yes	Format:`server_ip:server_rpc_port:server_sql_port`.
cluster_url	Cluster URL specified during startup	`\|`(English half-width)	No	When OceanBase has a cluster URL, obcdc is used to obtain rootserver information, supporting high availability for servers.
cluster_user	Username in the sys tenant	Empty (user-specified, required)	No	You must configure a user in the sys tenant with read permission on internal tables (OceanBase databases).
cluster_password	Password of the above user	Empty (user-specified, required)	No	None
cluster_db_name	Database name where the internal table for obcdc query is located	oceanbase	No	No modification is required. By default, internal tables are stored under the oceanbase database.
tenant_endpoint	List of Machines Where Tenant Resides	`\|` (English half-width)	No	Format:`host:sql_port`, use `\|` separator.
tenant_user	Tenant username	`\|`(English half-width)	No	Format:`user_name@tenant_name`or`user_name@tenant_name#cluster`.
tenant_password	Password corresponding to the above tenant username	`\|`(English half-width)	No	None
config_fpath	Configuration File Dump Path	etc/liboblog.conf	No	All configuration information of obcdc is dumped to this file.
timezone	Time zone of obcdc	+8:00	No	The time zone that affects data formatting output must be consistent with the data source configuration. The default is UTC+8.
timezone_info_path	Specifies the directory where the timezone metadata files are located.	etc/timezone_info.conf	Yes	`meta_data_refresh_mode`Set to`data_dict`When doing so, you need to extract the files from the RPM package.`timezone_info.conf`Files are placed in this directory.
skip_ob_version_compat_check	Whether to skip the OceanBase version compatibility check	0	No	obcdc in OceanBase Database V3.x supports only synchronizing data between OceanBase Database V2.x and V3.x, and the version number of obcdc must be greater than that of OceanBase Database (the major and minor version numbers are compared).
cluster_version_refresh_interval_sec	Query the minimum version number of OBServer nodes in an OceanBase cluster	600	No	Specifies the interval for refreshing the OceanBase cluster version, in seconds.
log_router_background_refresh_interval_sec	Log Stream Metadata Refresh Frequency	10	Yes	The interval at which the backend refreshes the server information corresponding to the log stream, in seconds.

Parameter	Meaning	Default Value	Dynamic Change Allowed	Remarks
working_mode	Working Mode	storage (commercial edition)	No	Try to control the transaction size for your business. If large transactions are present in your business scenario, it is recommended to use the persistent mode. In persistent mode, it is recommended to deploy obcdc on an SSD disk.
store_service_path	Data storage path in obcdc persistent mode	./storage	No	Effective only in persistent mode. Relative path: A relative path stored under the directory where the process calling obcdc resides. Absolute path: Stored under a specified absolute path, for example, store_service_path=/data/1.

Synchronization granularity

obcdc supports synchronizing data in multiple dimensions. A single obcdc instance can synchronize a cluster, one or multiple tenants, several databases, or several tables.

Synchronization Granularity	Single obcdc	Multiple obcdc instances
cluster	Supported (not supported for single OBDC synchronization of multiple clusters)	Supported
Tenant	Supported	Supported
database	Not supported	Not supported
table	Not supported	Not supported (see the multi-instance parameters below).

If a tenant has a large volume of traffic and it is difficult for a single-instance obcdc to achieve real-time data synchronization for the entire cluster, you can use multiple obcdc instances to synchronize the same cluster to share the load. Each instance synchronizes data from different tenants.

Parameter	Meaning	Default Value	Dynamic Change Allowed	Remarks
enable_white_black_list	Controls whether to enable allowlist and blocklist for obcdc.	1	No	Enabled by default. Blocklist and allowlist configurations take effect. When disabled, data for the entire tenant will be synchronized, limited to the tenants specified in the allowlist.
tb_white_list	Allowlist of Synchronized Tables	..*	No	Format: tenant name.database name.table name (for example, mytenant1.db1.tb1\	mytenant2.db2.*).
tb_black_list	Blacklist of Synchronized Tables	`\|`	No	The format is the same as above.
tablegroup_white_list	Synchronized Tablegroups Allowlist	.	No	Format: tenant name.tablegroup name, for example, (mytenant1.*\	or_tenant.tg).
tablegroup_black_list	Synchronized Tablegroups in Blocklist	`\|`	No	The format is the same as above.
enable_filter_sys_tenant	Whether to filter data synchronized from the sys tenant	0	No	It is enabled when the sys tenant is abnormal but the user tenant is normal.

Note

obcdc provides data filtering capabilities based on table and tablegroup allowlists and blocklists:

Only tables/tablegroups that are in the allowlist and not in the blocklist are synchronized. The default allowlist includes all tables/tablegroups under all tenants, and the blocklist is empty by default. It is recommended to use the allowlist in production environments to synchronize data for specified tenants, rather than using the default values (which will pull redundant data).
The configuration uses fnmatch for regular expression matching. The default match rule is case-insensitive. If enable_oracle_mode_match_case_sensitive=1 is configured, name matching is case-sensitive for tenants in ORACLE-compatible mode.

Parameter	Meaning	Default Value	Dynamic Change Allowed	Remarks
instance_num	Total OBDCs Sharing Traffic	1	No	None
instance_index	Index of the current obcdc in the total count (can be understood as the hash bucket ID)	0	No	The value range is [0, instance_num). Each OBDC only processes`hash(tenant_id, ls_id) % instance_num = instance_idx`of the log stream data.
enable_global_unique_index_belong_to_multi_instance	Whether to allow synchronizing tables with globally unique indexes in multi-instance scenarios	0	Yes	A value of 0 indicates that synchronizing globally unique index tables across multiple instances is not allowed.

Traffic control

To prevent Out-of-Memory (OOM) issues caused by data accumulation in memory under abnormal circumstances, obcdc provides traffic control capabilities. Traffic control is triggered based on the internal state of obcdc, pausing the pulling of new data until the obcdc status recovers. The traffic control feature is controlled by the following parameters. Adjust the corresponding parameters as needed to modify the throttling level.

Parameter	Meaning	Default Value	Dynamic Change Allowed	Remarks
memory_limit	Memory Limit for obcdc When Flow Control Is Triggered	`20G`	Yes	One of the flow control reference parameters, aiming to keep the OBDC memory usage within`memory_limit`Nearby (which OBDC tries to control) does not mean that OBDC uses at most`memory_limit`The minimum memory size is 2 GB.
memory_usage_warn_threshold	Set the memory usage threshold for triggering log pull throttling (compared to memory_limit).	85	Yes	None
system_memory_avail_percentage_lower_bound	Minimum Available System Memory Threshold (Percentage)	10	Yes	Value range: [10, 80].
part_trans_task_active_count_upper_bound	Maximum Active Partition Transactions	200000	Yes	The number of active partition transaction structures in memory (allocated and not reclaimed).
storager_task_count_upper_bound	Throttling threshold for the number of tasks to be persisted by the storager module	1000	Yes	The minimum value is 1.
storager_mem_percentage	Controls the multiple by which the persistence module occupies the relative flow control memory.	1	Yes	A value of 0 indicates automatic adjustment.
part_trans_task_reusable_count_upper_bound	Maximum Number of Partition Transactions to be Reused	10240	Yes	The number of tasks that are waiting to be output to the user queue, waiting for user output, waiting for user return, and not being garbage collected.
ready_to_seq_task_upper_bound	Maximum Number of Pending Tasks	2000	Yes	The maximum number of pending-sequence tasks is: the number of tasks pending parsing + the number of tasks pending formatting + the number of tasks pending persistence.
pause_fetcher	Force Log Pull Suspension	0	Yes	A value of 0 indicates that the result of the flow control computation logic is ignored, and log pulling is forcibly paused.
direct_load_inc_thread_num	Number of threads for reading and parsing incremental direct load logs	0	Yes	The automatic configuration parameter for memory throttling, which can be set according to the parameters configured in obcdc.`memory_limit`It can be automatically adjusted or manually modified to enable dynamic adjustment. Notice When using the incremental direct load feature, carefully adjust this parameter when synchronizing data via obcdc. Otherwise, it may affect the memory throttling and cause memory limits to be exceeded.
direct_load_inc_queue_backlog_lowest_tolerance	Threshhold for Task Congestion Triggering Rate Limit	0	Yes	The automatic configuration parameter for memory throttling, which can be set according to the parameters configured in obcdc.`memory_limit`It can be automatically adjusted or manually modified to enable dynamic adjustment. Notice When using the incremental direct load feature, carefully adjust this parameter when synchronizing data via obcdc. Otherwise, it may affect the memory throttling and cause memory usage to exceed the limit.

Traffic control reference conditions:

Condition 1: The number of active partitions exceeds the upper threshold (part_trans_task_active_count_upper_bound) || The memory held by obcdc exceeds the upper threshold (memory_limit) || The system available memory is lower than the lower threshold (system_memory_avail_percentage_lower_bound).
Condition 2: The number of partition transaction structures pending reuse exceeds the upper threshold (part_trans_task_reusable_count_upper_bound) || The number of tasks ready for sequencing exceeds the upper threshold (ready_to_seq_task_upper_bound).
Condition 3 (since 3.x): The number of tasks pending persistence exceeds the threshold (storager_task_count_upper_bound) && The memory held by obcdc exceeds the flow control trigger memory (memory_limit) * The ratio of the memory occupied by the persistence module to the flow control memory (storager_mem_percentage).

The conditions for triggering flow control are: ((Condition 1 && Condition 2)|| Condition 3) || (pause-fetcher != 0).

The automatic adjustment strategies for the direct_load_inc_thread_num and direct_load_inc_queue_backlog_lowest_tolerance parameters are as follows:

memory_limit	2G	4G	8G	16G	32G	128G
direct_load_inc_thread_num	1	1	1	2	3	5
direct_load_inc_queue_backlog_lowest_tolerance	4096	8192	16384	32768	65536	131072

When memory is sufficient, you can appropriately increase the value of direct_load_inc_thread_num to improve the speed of reading and parsing incremental direct load data, and appropriately increase the task congestion threshold that triggers throttling (direct_load_inc_queue_backlog_lowest_tolerance). When memory is insufficient, you can appropriately decrease the values of direct_load_inc_thread_num and direct_load_inc_queue_backlog_lowest_tolerance, or keep their default values.

Monitoring information output

Parameter	Meaning	Default Value	Dynamic Change Allowed	Remarks
enable_dump_pending_trans_info	Controls whether to periodically collect statistics on and print the status of distributed transactions held by OBDC	0	Yes	A value of 0 indicates that the status of distributed transactions held by OBDCD is not periodically collected and printed. If configured as`1`Then it will be printed every 10 seconds.
print_fetcher_slowest_ls_num	Print the number of partitions with the slowest log pulling	10	Yes	None
print_rpc_handle_info	Controls whether to print RPC-related information.	0	Yes	A value of 0 indicates not to print RPC-related information.
print_stream_dispatch_info	Controls whether to print log stream pull information	0	Yes	A value of 0 indicates not to print log stream pull information.
print_ls_heartbeat_info	Controls whether to print partition heartbeat information	0	Yes	A value of 0 indicates not to print partition heartbeat information.
print_ls_serve_info	Controls whether to print partition service information (partition status, number of partition transactions).	0	Yes	A value of 0 indicates not to print partition service information (partition status, number of partition transactions).
print_participant_not_serve_info	Controls whether to print partition transaction information for all distributed transactions that are not serving (do not output data).	0	Yes	A value of 0 indicates not to print the partition transaction information for all distributed transactions that are not serving (do not output data).
print_ls_server_list_update_info	Controls whether to print detailed information about the server list when updating it.	0	Yes	A value of 0 indicates that detailed information about the server list is printed when the partition server list is not updated.
enable_formatter_print_log	Controls whether to allow the formatter to log data that is partially ignored during formatting.	0	Yes	A value of 0 indicates that the formatter is not allowed to output logs when partial unformatted data is ignored.

Parameter	Meaning	Default Value	Dynamic Change Allowed	Remarks
enable_direct_load_inc	Controls whether to synchronize incremental data for direct load	0	No	By default, incremental data is not synchronized for direct load in V4.3.1.
enable_output_virtual_generated_column	Controls whether to output virtual generated columns.	0	No	With`enable_output_by_table_def`together. Note For OceanBase Database V4.3.x, this parameter is available starting with V4.3.5 BP5. That is, when OceanBase Database is V4.3.5 BP5 or later in the V4.3.x series, CDC supports outputting virtual generated columns.

Metadata management

obcdc version 4.1 supports obtaining metadata (such as schema/log stream information) from a data dictionary, eliminating the need to send RPCs to OBServer nodes to pull logs.

Parameter	Meaning	Default Value	Dynamic Change Allowed	Remarks
meta_data_refresh_mode	Specifies the method for obtaining metadata such as schemas and log streams.	online	No	Online mode: Queries schema information from the server through SchemaService. Access to OBServer nodes is required. Data_dict mode: Parses schema information from the data dictionary in logs.

Tenant management

Parameter	Meaning	Default Value	Dynamic Change Allowed	Remarks
skip_rename_tenant_ddl	Whether to ignore DDL statements for renaming tenants	0	Yes	If a renamed tenant is not within the OBDC synchronization allowlist, no impact occurs. Otherwise, an error is reported and the process exits normally (because the rename operation violates the allowlist restrictions). In this case, it is recommended to modify the allowlist to support both the tenant before and after the rename. When this parameter is set to true, DDL statements for the renamed tenant are skipped, and data synchronization continues.
enable_oracle_mode_match_case_sensitive	Case Sensitivity in Allowlist and Blocklist Matching for OceanBase-Oracle Mode Tenants	0	No	None

Parameter	Meaning	Default Value	Dynamic Change Allowed	Remarks
ls_count_upper_limit	Number of Partition Progresses	2000000	No	Up to 200 million partitions are supported.
check_switch_server_interval_min	Periodically check whether a partition needs to switch the log pulling server	30	Yes	None

Parameter	Meaning	Default Value	Dynamic Change Allowed	Remarks
access_systable_helper_thread_num	Maximum Number of Connections in the Connection Pool for Executing SQL	64	No	Value range: [48, 1024].
rs_sql_connect_timeout_sec	SQL Connection Timeout for Root Service	40	Yes	None
rs_sql_query_timeout_sec	SQL Request Timeout Period for Root Service	30	Yes	None
tenant_sql_connect_timeout_sec	SQL Connection Timeout Period for Tenant	40	Yes	None
tenant_sql_query_timeout_sec	Timeout period for tenant SQL requests	30	Yes	None
sql_server_change_interval_sec	Cycle for switching execution servers of SQL requests	60	Yes	None

Filter data based on cluster_id

obcdc provides data filtering capabilities based on a cluster_id blacklist: OceanBase defines a valid range for cluster_ids, but to prevent synchronization of unwanted data, users can specify a cluster_id when writing data. To configure the cluster_ids for writing data at the source side, refer to ob_org_cluster_id.

Do not synchronize data whose cluster_id is outside the valid range specified by OceanBase and OMS ([1, 4294901759] U [4294901760, 4294967295]).
Do not synchronize data whose cluster_id is in the cluster_id_blacklist.
Each cluster_id in the cluster_id_blacklist must be within the range of cluster_id_value_min and cluster_id_value_max.

Parameter	Meaning	Default Value	Dynamic Change Allowed	Remarks
cluster_id_black_list	Synchronized Cluster ID Blocklist	`\|`	No	Separate multiple cluster IDs with half-width characters `\|`, where each `cluster_id` value is between `cluster_id_value_min` and `cluster_id_value_max`.
cluster_id_black_value_min	Minimum Cluster ID in Synchronization Blocklist	2147473648	No	None
cluster_id_black_value_max	Maximum Synchronized Cluster IDs in Blocklist	2147483647	No	None

Server-level blacklist

obcdc initiates SQL and RPC requests to OBServer nodes. We provide configuration items to block specific machines for SQL execution and RPC execution (applicable to all requests).

Additionally, obcdc pulls logs at the partition level. Therefore, it has a built-in partition-level pull-log blacklist. Machines that time out or report errors when pulling partition logs are added to this blacklist. The process of adding a machine to the blacklist and removing it from the blacklist is automatic.

Parameter	Meaning	Default Value	Dynamic Change Allowed	Remarks
server_blacklist	Configure the RPC request machine blacklist. obcdc will not send RPC requests to machines on this list.	`\|`	Yes	The format is`svr_ip:rpc_port`Multiple OBServer nodes are connected by using the `\| Separated by` `. Machines in this list will not be pulled for logs. You can manually add an OBServer node to this list if it cannot provide log service normally (for example, due to network partitioning or excessive latency).
sql_server_blacklist	Configure a blocklist of machines for SQL requests. obcdc will not send SQL requests to machines in this blocklist.	`\|`	Yes	The format is`svr_ip:rpc_port`Multiple OBServer nodes are connected by using the `\| Separated by` .

Partition-level pull-log server blacklist control (typically not modified)

Parameter	Meaning	Default Value	Dynamic Change Allowed	Remarks
blacklist_survival_time_sec	Waiting Time of Machines in the Blocklist	30	No	None
blacklist_survival_time_upper_limit_min	Maximum Time in Blocklist	4	Yes	None
blacklist_survival_time_penalty_period_min	Threshold for Doubling Blocklist Duration When a Machine Repeatedly Gets Added to the Blocklist	1	Yes	None
blacklist_history_overdue_time_min	How long will a machine remain in the blocklist history before being deleted?	30	Yes	Minimum value: 10
blacklist_history_clear_interval_min	Cycle for Cleaning Machine Information from the Blocklist	20	Yes	Minimum value: 10

Parameter	Meaning	Default Value	Dynamic Change Allowed
all_server_cache_update_interval_sec	Cache update cycle for server list information	5	Yes
all_zone_cache_update_interval_sec	Cache update cycle of zone information	5	Yes

Parameter	Meaning	Default Value	Dynamic Change Allowed	Remarks
idle_pool_thread_num	Number of Threads for Processing Pending Partition Log Pull Tasks	4	No	The value range is [1, 32].
dead_pool_thread_num	Number of Threads for Processing Log Pull Tasks from Recycled Partitions	1	No	The value range is [1, 32].
stream_worker_thread_num	Number of threads for distributing partition log pulling tasks	8	No	Value range: [1,64].
start_lsn_locator_thread_num	Number of Threads for Locating the Partition Log Start	4	No	The value range is [1, 32].
lob_data_merger_thread_num	Number of Lobs Processing Threads	2	No	Value range: [1, +∞).
start_lsn_locator_locate_count	Number of Requests for Locating the Start of Logs Completed	1	No	The minimum value is 1. To locate the starting log ID of a partition, you need to ensure that a specified number of partition replicas return the same starting log ID.
skip_start_lsn_locator_result_consistent_check	Skip consistency check for start log IDs	No	No	None
svr_stream_cached_count	Initial Pool Size of Machine Log Stream Objects	16	No	The minimum value is 1.
fetch_stream_cached_count	Initial Size of Partition Log Stream Object Pool	16	No	The minimum value is 1.
start_lsn_locator_rpc_timeout_sec	Timeout Duration for RPC to Locate the Start Log ID of a Partition	60	Yes	The minimum value is 1.
start_lsn_locator_batch_count	RPC Batch Size for Locating the Start Log ID of a Partition	2000	Yes	The minimum value is 1.
heartbeat_interval_sec	Partition Heartbeat RPC Cycle	1	Yes	The minimum value is 1.
fetch_log_rpc_timeout_sec	Pull Partition Log RPC Timeout Period	15	Yes	The minimum value is 1.
progress_limit_sec_for_dml	Maximum DML Data Pull Log Progress	300	Yes	The minimum value is 1. To ensure that the progress of all partitions is roughly consistent (preventing some partitions from pulling logs too quickly), the upper limit for logs provided by the server is set to the minimum progress of all partitions plus progress_limit_sec_for_dml.
ls_fetch_progress_update_timeout_sec	Threshold for RPC Timeout on Partition Log Pull	3	Yes	The minimum value is 1.
ls_fetch_progress_update_timeout_sec_for_lagged_replica	Timeout Threshold for Pulling Logs from Lagging Replicas	15	Yes	The minimum value is 1.
enable_continue_use_cache_server_list	Information about servers using the cache	0	No	It is enabled when the sys tenant is abnormal but the user tenant is normal.
fetching_log_mode	Used to specify the log pull mode.	integrated	No	integrated mode: The default log pull mode. It pulls logs by sending RPCs to OBServer nodes. You must configure the OBServer node address (cluster_url or rootserver_list), and the username (cluster_user) and password (cluster_password) of the system tenant. direct mode: Directly consumes archived logs without sending RPCs to OBServer nodes. You must configure the archive destination (such as an NFS path or OSS information). For details about archive destinations, see Log archiving overview. The machine where obcdc resides must have direct access to the archive destination. Notice obcdc does not support pulling discontinuous archived logs.

Parameter	Meaning	Default Value	Dynamic Change Allowed	Remarks
region	Configure the region for which OBDC prioritizes log pulling	default_region	Yes	Regions need to be retrieved from the internal tables of OceanBase Database. obcdc will preferentially pull logs from the OBServer nodes within the configured regions.

RPC module configuration (not recommended for modification)

Parameter	Meaning	Default Value	Value range	Dynamic Change Allowed
io_thread_num	Number of RPC IO Threads	4	[1, +∞)	No
rpc_result_cached_count	Initial Size of Log Pull RPC Result Object Pool	16	[1, +∞)	No
rpc_process_handler_time_upper_limit_msec	Maximum RPC Processing Time	200	[1, +∞)	Yes
rpc_result_count_per_rpc_upper_limit	Maximum number of outstanding log pull RPCs in a single log stream. Once this limit is reached, the log pull RPC will be suspended.	16	[1, +∞)	Yes

Parameter	Meaning	Default Value	Dynamic Change Allowed	Remarks
ssl_client_authentication	Whether to enable secure communication	0	No	The default value is 0, which indicates that secure communication is not enabled.
ssl_external_kms_info	Secure communication method	file	No	For external use, only the file mode is supported. The key files are placed in the wallet directory under the obcdc startup directory (please create your own wallet directory). The following key files are placed there: ca.pem/client-cert.pem/client-key.pem.

Parameter	Meaning	Default Value	Value range	Dynamic Change Allowed
sequencer_thread_num	Distributed Transaction Scheduling Thread Pool Size	5	[1, +∞)	No
sequencer_queue_length	Pending Partition Transaction Queue	102400	[1, +∞)	No

REDO read control module

Parameter	Meaning	Default Value	Value range	Dynamic Change Allowed
redo_dispatched_memory_limit_exceed_ratio	When enable_output_trans_order_by_sql_operation=1 is set, it specifies the maximum size of redos that can be processed in memory (i.e., the allowed size is redo_dispatched_memory_limit_exceed_ratio * redo_dispatcher_memory_limit).	2	[1, +∞)	Yes
redo_dispatcher_memory_limit	Limit the Redo Size for Control Distribution Processing	512M	[128M, +∞)	Yes
extra_redo_dispatch_memory_size	A REDO balance allocated to participants with data skew to prevent OBDC from not outputting data due to deadlock.	4M	[0M, 512M]	Yes

Row data sorting module

Parameter	Meaning	Default Value	Value range	Dynamic Change Allowed
msg_sorter_task_count_upper_limit	Maximum Number of Tasks for Row Data Sorting Module in a Transaction	200000	[1, +∞)	No
msg_sorter_thread_num	Number of Threads for Row Data Sorting in a Transaction	1	[1, 32]	No

Configuration effective in persistent mode

Parameter	Meaning	Default Value	Dynamic Change Allowed
storager_thread_num	Thread Pool Size of the Persistence Module	10	No
storager_queue_length	Number of Pending Persistence Tasks	102400	No

Parameter	Meaning	Default Value	Dynamic Change Allowed
reader_thread_num	Thread Pool Size for Reading Data from the Persistence Module	10	No
reader_queue_length	Number of Tasks Awaiting Deserialization	102400	No

Parameter	Meaning	Default Value	Value range	Dynamic Change Allowed
batch_buf_count	Number of Memory Buffers for Redo Batch Persistence	10	[5, +∞)	No
batch_buf_size	Aggregate Buffer Size for Redo Batch Persistence	20MB	[2MB, +∞)	No

Parameter	Meaning	Default Value	Dynamic Change Allowed	Remarks
dml_parser_thread_num	Thread Pool Size for Parsing DML Statements	5	No	The minimum value is 1.
ddl_parser_thread_num	Thread Pool Size for Parsing DDL Statements	1	No	The minimum value is 1.
skip_reversed_schema_version	Ignore schema version rollback exception	0	No	The DDL processing is generally a process of monotonically increasing the schema version. If the schema version reverts, it indicates an exception. This feature allows you to configure the system to skip such exceptions.

Parameter	Meaning	Default Value	Dynamic Change Allowed	Remarks
formatter_thread_num	Data Formatting Thread Pool Size	10	No	The minimum value is 1.
skip_dirty_data	Skip outlier data	0	Yes	Current exception: Non-full-column logging (where only the information of changed columns is recorded in the CLOG. Parameter: binlog_row_image). Abnormal DDL operations on a tenant restored from physical backup.

Parameter	Meaning	Default Value	Dynamic Change Allowed	Remarks
enable_output_trans_order_by_sql_operation	Whether to output row data within a transaction in the order of SQL execution	0	No	The internal data modification order in OceanBase Database may not exactly match the SQL execution order sent by the client.
sort_trans_participants	Sort by Distributed Transaction Participant	1	No	It refers to sorting by the partitioning key. When combined with enable_output_trans_order_by_sql_operation, it can result in a stable output order of statements.
enable_output_hidden_primary_key	Whether to output the hidden primary key for tables without a primary key	0	No	For tables without a primary key, you can set enable_output_hidden_primary_key=1 to include the hidden primary key in the output.
enable_convert_timestamp_to_unix_timestamp	Whether to convert the timestamp to a UNIX integer time	0	No	None
enable_output_invisible_column	Output Hidden Columns	0	No	None
enable_output_by_table_def	Controls whether to output columns in the user-defined column order.	0	No	None
output_heartbeat_interval_msec	Output Safety Point Information Interval	1000	Yes	None

Resource recycling configuration (not recommended for modification)

Parameter	Meaning	Default Value	Dynamic Change Allowed	Remarks
resource_collector_thread_num	Resource Recycling Thread Pool Size	10	No	The minimum value is 1.
resource_collector_thread_num_for_br	Thread Pool Size for Binlog Record Recycling	7	No	It must be greater than resource_collector_thread_num.

Notice

Modifications to configurations not described in this topic are not recommended.

OceanBase

Customer Stories

Documentation

obcdc parameters

Cluster configuration

Metadata configuration

Synchronization granularity

Note

Traffic control

Notice

Notice

Monitoring information output

Note

Metadata management

Tenant management

Filter data based on cluster_id

Server-level blacklist

Partition-level pull-log server blacklist control (typically not modified)

Notice

RPC module configuration (not recommended for modification)

REDO read control module

Row data sorting module

Configuration effective in persistent mode

Resource recycling configuration (not recommended for modification)

Notice

OceanBase

Customer Stories

Documentation

obcdc parameters

Cluster configuration

Metadata configuration

Working mode related

Synchronization granularity

Allowlist and blocklist related configuration

Note

Multi-instance related configuration

Monitoring related configuration

Traffic control

Notice

Notice

Monitoring information output

Feature control related configurations

Note

Metadata management

Tenant management

Fetcher module related configurations

SQL query related configurations

Filter data based on cluster_id

Server-level blacklist

Partition-level pull-log server blacklist control (typically not modified)

Server cache information related configuration

Log pull related configuration

Notice

Log pull priority related

RPC module configuration (not recommended for modification)

Secure communication related

Sequencer module related configuration

REDO read control module

Row data sorting module

Configuration effective in persistent mode

Storager module related configuration

Data Processor module related configuration

Configuration related to redo batch persistence

Configuration related to the parser module

Configuration related to the formatter module

Configuration related to outputting binlog records

Resource recycling configuration (not recommended for modification)

Notice