Overview|V4.2.2|OceanBase Database| docs|Distributed Database

Parameter	Description
enable_ob_ratelimit	Enables bandwidth throttling between regions in RPC connections.
ob_ratelimit_stat_period	The time interval for calculating and updating the maximum bandwidth of an OBServer node.

Parameter name	Description
balancer_log_interval	The interval for the disaster recovery task thread to record statistics logs.
balancer_task_timeout	The timeout period of background tasks such as load balancing.
balancer_tolerance_percentage	The tolerance level for the load balancing strategy within a tenant. Units with disk usage within the range of the mean value plus or minus the tolerance level will not trigger an balancing action.
server_balance_critical_disk_waterlevel	The water level for triggering the disk space load balancing feature.
server_balance_disk_tolerance_percent	The tolerance level for the disk load balancing strategy between nodes.
resource_hard_limit	The overallocation percentage of CPU resources.
enable_sys_unit_standalone	Specifies whether to isolate system tenant units to nodes.

Parameter name	Description
enable_rereplication	Specifies whether to enable the automatic resynchronization feature.
ls_meta_table_check_interval	The check interval of the background inspection thread for the DBA_OB_LS_LOCATIONS/CDB_OB_LS_LOCATIONS view.
sys_bkgd_migration_change_member_list_timeout	The timeout period for changing the Paxos member group during replica migration.
sys_bkgd_migration_retry_num	The maximum number of retries for replica migration.

Parameter name	Description
all_server_list	The IP addresses of all servers in the cluster.
cluster	The name of the OceanBase cluster.
cluster_id	The ID of the OceanBase cluster.
rpc_timeout	The timeout period for internal cluster requests.

Parameter name	Description
sql_login_thread_count	The number of threads for processing SQL login requests.

Parameter name	Description
cpu_count	The total number of CPU cores in the system. If set to 0, the system will automatically detect the number of CPU cores.
server_balance_cpu_mem_tolerance_percent	The tolerance for CPU and memory resource imbalance in node load balancing.
server_cpu_quota_max	The maximum CPU quota available to the system.
server_cpu_quota_min	The minimum CPU quota available to the system. The system will automatically reserve this quota.
token_reserved_percentage	The percentage of idle tokens reserved for a tenant during CPU scheduling in the sys tenant.
workers_per_cpu_quota	The number of worker threads allocated to each CPU quota.

Parameter name	Description
config_additional_dir	Multiple directories for storing additional configuration files for redundancy.

Parameter name	Description
datafile_disk_percentage	The percentage of total space on the disk where data_dir is located. The disk where data_dir is located will be initialized by OceanBase Database for storing data.
data_disk_usage_limit_percentage	The maximum percentage of data files that can be written. After this threshold is reached, data migration is prohibited.
enable_sql_operator_dump	Specifies whether to write intermediate results of SQL processing to the disk to free up memory space.
global_write_halt_residual_memory	The global memory threshold for halting normal tenant writes (`sys` tenant is not affected).
leak_mod_to_check	Specifies the memory leak check module. This parameter is for internal debugging.
memory_chunk_cache_size	The size of memory chunks in the cache of the memory allocator.
memory_limit	The total size of available memory.
memory_limit_percentage	The percentage of total memory size that is available to the system.
memory_reserved	The size of memory reserved for the KVCache.
memstore_limit_percentage	The maximum percentage of memory allowed for MemStores used by a tenant out of its total available memory.
system_memory	The size of memory reserved for tenant ID `500`.
use_large_pages	The management of large pages used by the database.
datafile_maxsize	The maximum size for automatic expansion of disk files.
datafile_next	The incremental step for automatic expansion of disk files.

Parameter name	Description
debug_sync_timeout	Specifies the timeout period of the Debug Sync feature.
enable_rich_error_msg	Specifies whether to add debugging information, such as the server address, timestamp, and trace ID, to client messages.

Parameter name	Description
default_compress_func	Specifies the default compression algorithm for table data. You can also specify a different compression algorithm when you create a table.
default_compress	Specifies the default compression strategy when you create a table in Oracle mode.

Parameter name	Description
log_disk_size	The size of the redo log disk.
log_disk_percentage	The maximum percentage of space that redo logs can occupy on a disk.
clog_sync_time_warn_threshold	The warning threshold for the time required to synchronize transaction logs. A WARN log is generated when the synchronization time exceeds the threshold.
dtl_buffer_size	The size of the cache used by the SQL data transmission module.
ignore_replay_checksum_error	Specifies whether to ignore checksum errors that occur during transaction log replay.
trx_2pc_retry_interval	The interval for automatic retries after a failure in two-phase commit.
standby_fetch_log_bandwidth_limit	The maximum bandwidth, in bytes per second, allowed for fetching logs from the primary tenant to the standby tenant.
log_storage_warning_tolerance_time	The time allowed after I/O failures on the log disk occur before the disk is marked as failed and the primary tenant is switched.

Parameter name	Description
enable_major_freeze	Specifies whether to enable the automatic global freeze feature.
micro_block_merge_verify_level	The verification level of macroblocks during a minor compaction.
row_compaction_update_limit	The number of modifications triggering a minor compaction of in-memory row-based data.

Parameter name	Description
px_workers_per_cpu_quota	The proportion of parallel execution worker threads.
px_task_size	The amount of data processed per task by the SQL parallel query engine.
max_px_worker_count	The maximum number of threads used by the SQL parallel query engine.

Parameter name	Description
bf_cache_miss_count_threshold	The number of times a macroblock must fail to be found in the cache before creating a Bloom filter cache.
bf_cache_priority	The priority of the Bloom filter cache.
cache_wash_threshold	The capacity threshold that triggers cache cleanup.
fuse_row_cache_priority	The priority of the fuse row cache in the cache system.
user_row_cache_priority	The priority of the baseline data row cache in the cache system.
autoinc_cache_refresh_interval	The refresh interval of the auto-increment column cache.
plan_cache_evict_interval	The interval at which the system eliminates execution plans from the cache.
index_block_cache_priority	The priority of the metadata index microblock cache.
opt_tab_stat_cache_priority	The priority of the statistics cache.
tablet_ls_cache_priority	The priority of the tablet mapping cache.
user_block_cache_priority	The priority of the data block cache in the cache system.

Parameter	Description
virtual_table_location_cache_expire_time	The expiration time of the location information cache for virtual tables.
location_cache_refresh_rpc_timeout	The RPC timeout period for refreshing the `location_cache`.
location_cache_refresh_sql_timeout	The SQL timeout period for refreshing the `location_cache`.
location_cache_refresh_min_interval	The minimum interval for refreshing the location cache, to prevent excessive refresh requests from causing high system pressure.
location_cache_cpu_quota	The CPU quota for the location cache module.
location_fetch_concurrency	The maximum number of concurrent refreshes of the location cache on a single server.
location_refresh_thread_count	The number of threads on an OBServer node for requesting partition location information from the Root Service.

Parameter name	Description
enable_record_trace_log	Specifies whether to record trace logs.
enable_async_syslog	Specifies whether to enable asynchronous write of system logs.
enable_syslog_recycle	Specifies whether to enable the recycle switch for old logs before startup. It is used in conjunction with `max_syslog_file_count` to determine whether the recycle logic applies to old log files.
enable_syslog_wf	Specifies whether to write WARN-level and higher system logs to a separate log file.
max_string_print_length	The maximum length of a line of text in trace logs.
max_syslog_file_count	The maximum number of log files that can be accommodated before the recycle logic is triggered.
syslog_level	The system log level.
trace_log_sampling_interval	The time interval for periodic recording of trace logs.
diag_syslog_per_error_limit	The maximum number of DIAG system logs that are allowed per error code within one second. Logs exceeding this threshold are not recorded.

Parameter name	Description
tablet_meta_table_check_interval	The check interval for the background inspection thread of the DBA_OB_TABLET_REPLICAS or CDB_OB_TABLET_REPLICAS view.
tablet_meta_table_scan_batch_count	The number of tablets cached in memory during the iteration of the tablet meta table.
tablet_size	The size of each shard for internal parallel processing (such as major compaction and query) in a partition.

Parameter name	Description
weak_read_version_refresh_interval	The refresh interval for weak-consistency read versions, which affects the latency of weak-consistency read data.
large_query_worker_percentage	The percentage of worker threads reserved for handling large queries.
large_query_threshold	The execution time threshold.
trace_log_slow_query_watermark	The execution time threshold. A slow query whose execution time exceeds the threshold has its trace logs printed to system logs.

Parameter name	Description
rootservice_async_task_queue_size	The size of the asynchronous task queue in Root Service.
rootservice_async_task_thread_count	The size of the thread pool for asynchronous tasks in Root Service.
rootservice_list	The list of servers where Root Service and its replicas reside.
rootservice_ready_check_interval	The time interval for checking the cluster status after Root Service starts.
rootservice_memory_limit	The maximum memory capacity allowed to Root Service.
lease_time	The lease duration for heartbeats.
server_check_interval	The time interval for checking the consistency of the server table.
server_permanent_offline_time	The time threshold for determining a permanently offline node. After a node's heartbeat is interrupted for this period of time, the node is considered to be permanently offline, and the data replicas on the node need to be automatically supplemented.
ob_event_history_recycle_interval	The interval for recycling historical events.

Parameter	Description
rdma_io_thread_count	The number of RDMA I/O threads for Libreasy.
syslog_io_bandwidth_limit	The maximum disk I/O bandwidth allowed for system logs. System logs exceeding the bandwidth limit will be discarded.
disk_io_thread_count	The number of disk I/O threads. It must be an even number.
net_thread_count	The number of network I/O threads.

Parameter	Description
sql_net_thread_count	The number of I/O threads for a MySQL cluster, which is also the number of `global_sql_nio_server` threads. The default value of 0 indicates to use the value of the `net_thread_count` parameter.

Parameter	Description
enable_tcp_keepalive	Specifies whether to enable the keepalive mechanism for client connections.
tcp_keepidle	The time interval in seconds after a client connection is established with the server before a keepalive probe packet is sent if no data is being transmitted.
tcp_keepintvl	The time interval in seconds between two keepalive probes after the keepalive mechanism is enabled.
tcp_keepcnt	The maximum number of retries before a non-active connection is closed.

Parameter	Description
rpc_client_authentication_method	The security authentication method for RPC clients.
rpc_server_authentication_method	The security authentication method for RPC servers.

Parameter	Description
ob_startup_mode	The startup mode of OBServer nodes. This parameter can be modified only during the first startup.

Parameter name	Description
builtin_db_data_verify_cycle	The cycle for self-inspection of bad data blocks, in days. If the value is 0, the self-inspection is disabled.
data_storage_warning_tolerance_time	The tolerance time for the data disk status to be set to the WARNING state.
dead_socket_detection_timeout	The interval for detecting failed sockets.
enable_sys_table_ddl	Specifies whether to allow manual creation of system tables.
internal_sql_execute_timeout	The interval for system internal DML requests.
migration_disable_time	The period of time to suspend data migration for a node after data migration fails due to a full disk or other reasons.
schema_history_expire_time	The expiration time of metadata history data.
datafile_size	The size of data files. Generally, you do not need to specify this parameter.
devname	The name of the network card that the service process binds to.
enable_perf_event	Specifies whether to enable the collection of performance events.
enable_record_trace_id	Specifies whether to record the trace ID set by the application.
enable_upgrade_mode	Specifies whether to enable upgrade mode. In upgrade mode, some system background features are suspended.
enable_ddl	Specifies whether to allow DDL operations.
high_priority_net_thread_count	The number of high-priority network threads. The value `0` indicates that this feature is disabled.
mysql_port	The port number for the SQL service protocol.
obconfig_url	The URL address of the OBConfig service.
rpc_port	The port number for remote access.
sql_protocol_min_tls_version	The minimum version number of the SSL/TLS protocol used for an SSL connection for SQL statements.
ssl_client_authentication	Specifies whether to enable the SSL connection feature.
stack_size	The size of the call stack for program functions.
tenant_task_queue_size	The size of the request queue for each tenant.
zone	The name of the zone to which the node belongs. Generally, you do not need to specify this parameter.
ssl_external_kms_info	Records some information on which the SSL feature of OceanBase Database depends. The information is recorded in a JSON string and includes relevant configurations for different SSL usage scenarios. The JSON string must contain a `ssl_mode` field.
recyclebin_object_expire_time	Automatically purges expired schema objects from the recycle bin.
default_row_format	The default row format used when creating a table in MySQL mode.
enable_sql_audit	Specifies whether to enable SQL auditing.
min_observer_version	The application version number of the minimum OBServer node in the cluster.
sys_bkgd_net_percentage	The percentage of network bandwidth available to background system tasks.
schema_history_recycle_interval	The interval for recycling `schema` multi-version records in the system.
enable_asan_for_memory_context	When ob_asan is used, specifies whether to allow ObAsanAllocator (default) as the MemoryContext allocator.

Parameter name	Description
plan_cache_high_watermark	The threshold of memory usage of the execution plan cache. When the memory usage exceeds this threshold, automatic plan eviction is triggered.
plan_cache_low_watermark	The threshold of memory usage of the execution plan cache. When the memory usage falls below this threshold, plan eviction is stopped.
tenant_cpu_variation_per_server	The allowed deviation of CPU quota scheduling among multiple units of a tenant.
system_trace_level	The log level of system tracing logs.

Parameter	Description
connection_control_failed_connections_threshold	The threshold of failed login attempts.
connection_control_min_connection_delay	The minimum duration of account lockout after the failed login attempt threshold is reached.
connection_control_max_connection_delay	The maximum duration of account lockout. When the maximum duration is reached, the duration does not increase even if the login attempt fails again.

Parameter	Description
balancer_idle_time	The interval for waking up idle load balancing and background tasks threads.
enable_rebalance	Specifies whether to enable automatic load balancing.
enable_transfer	Specifies whether to allow transfer within a tenant. This parameter is ineffective when `enable_rebalance` is disabled.
partition_balance_schedule_interval	The scheduling cycle of partition balancing.

Parameter name	Description
log_restore_concurrency	The maximum number of concurrent log restore threads.
log_archive_concurrency	The maximum number of concurrent log archive threads.

Parameter name	Description
audit_sys_operations	Specifies whether to track the operations of system users.
audit_trail	Specifies whether to enable database audit.

Parameter name	Description
rpc_memory_limit_percentage	The maximum memory usage allowed for RPCs, which is the percentage of the total memory of the tenant.

Parameter name	Description
log_disk_utilization_limit_threshold	The threshold of log disk utilization for limiting log write. When the usage of the log disk exceeds the total size of the log disk space for the tenant multiplied by this threshold, log write is no longer allowed.
log_disk_utilization_threshold	The threshold of log disk utilization for log file reuse. When the usage of the log disk exceeds the total size of the log disk space for the tenant multiplied by this threshold, log file reuse is performed.
writing_throttling_maximum_duration	The time required for allocating the remaining MemStore memory after write throttling is triggered, in seconds. This parameter controls the write speed.
writing_throttling_trigger_percentage	The threshold of write speed, specified as a percentage.
standby_db_fetch_log_rpc_timeout	The RPC timeout period for pulling logs from the primary database, in seconds. This parameter is used to control the log transmission service in the standby database. When this service detects that a server in the primary database is unavailable, it will switch to another server after a period of time.
log_disk_throttling_percentage	The percentage of unrecoverable log disk space. When this parameter is reached, write throttling is triggered.
log_transport_compress_all	Specifies whether to compress logs during transmission.
log_transport_compress_func	The compressor for log transmission.

Parameter name	Description
default_progressive_merge_num	The default number of minor compactions for a newly created table.
major_freeze_duty_time	The time when the daily scheduled freeze and major compaction are triggered.
major_compact_trigger	The number of freezes that trigger a global major compaction.
minor_compact_trigger	The threshold of the number of SSTables that triggers a minor compaction.
undo_retention	The system-retained version data range, in seconds, for minor compaction.
merger_check_interval	The scheduling interval of the threads that check the status of minor compactions.
freeze_trigger_percentage	The memory usage threshold of tenants that triggers a global freeze.

Parameter name	Description
cpu_quota_concurrency	The maximum number of concurrent operations allowed for each CPU quota.

Parameter name	Description
external_kms_info	Stores some key management information.
tde_method	Specifies the method for transparently encrypting tablespaces.

Parameter name	Description
plsql_code_type	Specifies the compilation type of PL/SQL code.
plsql_debug	Specifies whether to compile a debug version.
plsql_optimize_level	Specifies the optimization level during compilation.
plsql_v2_compatibility	Specifies Oracle compatibility features of PL/SQL. Notice This parameter applies only to Oracle mode and is currently not in effect.

Configuration item	Description
enable_sql_extension	Specifies whether to enable SQL extensions for the tenant.
compatible	Controls the compatibility behavior of related features in the tenant. This configuration item cannot be set.

Configuration item	Description
enable_monotonic_weak_read	Specifies whether to enable monotonic reads.
query_response_time_stats	Specifies whether to enable statistics collection for the `information_schema.QUERY_RESPONSE_TIME` view.
query_response_time_flush	Specifies whether to flush the `information_schema.QUERY_RESPONSE_TIME` view and re-read `query_response_time_range_base`.
query_response_time_range_base	The interval for the time parameter in the `information_schema.QUERY_RESPONSE_TIME` view to collect statistics.

Configuration item	Description
ob_proxy_readonly_transaction_routing_policy	Controls whether the Proxy's routing of transactions is affected by read-only statements.

Parameter	Description
io_category_config	Specifies the percentage of I/O requests for each category.

Parameter	Description
compaction_low_thread_score	The number of worker threads for minor compaction.
compaction_high_thread_score	The number of worker threads for major compaction.
compaction_mid_thread_score	The number of worker threads for incremental major compaction.
ha_high_thread_score	The number of worker threads for high-priority threads in high availability.
ha_mid_thread_score	The number of worker threads for medium-priority threads in high availability.
ha_low_thread_score	The number of worker threads for low-priority threads in high availability.
ob_compaction_schedule_interval	The interval for scheduling compactions.
compaction_dag_cnt_limit	The maximum number of DAGs in the compaction DAG queue.
compaction_schedule_tablet_batch_cnt	The maximum number of partitions scheduled in each batch for compaction.
tenant_sql_login_thread_count	The number of threads for MySQL tenant logins, which is the number of `mysql_queue` threads. The default value of 0 means to use the value of `unit_min_cpu`.
tenant_sql_net_thread_count	The number of I/O threads for MySQL tenants, which is the number of `sql_nio_server` threads. The default value of 0 means to use the value of `unit_min_cpu`.

Parameter	Description

Parameter name	Description
enable_early_lock_release	Specifies whether to enable the early lock release feature.
workarea_size_policy	Specifies the strategy for manually or automatically adjusting the size of an SQL workspace.
open_cursors	Specifies the maximum number of cursors that can be opened simultaneously in a session.
ob_ssl_invited_common_names	Records the application identities of the tenant, which are obtained from the `cn` field (common name) of the `subject` field of the client-side certificate during two-way SSL authentication.
ob_enable_batched_multi_statement	Specifies whether to enable the group execution optimization for the batch processing feature.
job_queue_processes	Specifies the maximum number of jobs that can run simultaneously on a tenant, to control the jobs from monopolizing the tenant's resources. Notice This parameter takes effect only in Oracle mode.
default_auto_increment_mode	Specifies the default auto-increment mode.
ob_query_switch_leader_retry_timeout	The maximum retry duration for failed queries, in microseconds (us).
default_enable_extended_rowid	Specifies whether to create a table in the extended ROWID mode by default.
dump_data_dictionary_to_log_interval	The interval for persisting the data dictionary of a tenant to logs.
enable_user_defined_rewrite_rules	Specifies whether to enable user-defined rewrite rules.

Configuration item name	Description
sql_work_area	The amount of memory available for tenant workspaces.
max_stale_time_for_weak_consistency	The maximum allowed staleness for weak-consistency read operations.

Customer Stories

Documentation

Overview

Cluster-level configurations

Minor compaction and major compaction

PX

Background execution threads

Others

Unsupported parameters

Tenant-level parameters

Note

Backup and restore

Audit

Memory space

Minor compaction and major compaction

CPU

PL

Note

Others

Not supported configuration items

Customer Stories

Documentation

Overview

Cluster-level configurations

Bandwidth-related

Load balancing-related

Replica-related

Cluster-related

SQL-related

CPU related

Directory path related

Memory space-related

Debugging-related

Compression algorithm-related

Transaction and transaction log-related

Minor compaction and major compaction

PX

Cache-related

Location cache-related

Log-related

Partition-related

Read/write and query-related

Root Service-related

I/O-related

Background execution threads

TCP-related

RPC authentication-related

Arbitration service-related

Others

Unsupported parameters

Tenant-level parameters

User login-related

Note

Load balancing-related

Backup and restore

Audit

Memory space

Transaction and transaction log-related

Minor compaction and major compaction

CPU

Encryption-related

PL

Compatibility-related

Note

Read/write and query-related

Routing-related

I/O-related

Background thread-related

Arbitration service-related

Others

Not supported configuration items