This topic describes the cluster-level and tenant-level parameters of OceanBase Database.
Cluster-level parameters
Security
Parameter |
Description |
|---|---|
| mysql_port | Specifies the port number for the SQL service protocol. |
| rpc_port | Specifies the port number for remote access. |
| sql_protocol_min_tls_version | Specifies the minimum version of the SSL/TLS protocol used for SSL connections to execute SQL statements. |
| ssl_client_authentication | Specifies whether to enable the SSL connection feature. |
| ssl_external_kms_info | Records information required for the operation of the SSL feature in OceanBase Database. This information is stored in a JSON string that contains at least the ssl_mode field. |
| enable_sql_audit | Specifies whether to enable the SQL audit feature. |
Backup and restore
Parameter |
Description |
|---|---|
| backup_backup_dest | Specifies the destination for backup data backup. |
| backup_backup_dest_option | Controls parameters related to backup backup. |
| backup_dest_option | Controls parameters related to backup. |
| backup_concurrency | Specifies the number of concurrent writes to the file system during backup. |
| backup_dest | Specifies the path for baseline backup and log archiving. |
| backup_log_archive_option | Defines the archiving options for backup logs. |
| backup_net_limit | Specifies the total bandwidth for cluster backup. |
| backup_recovery_window | Specifies the time period during which backup data can be restored. |
| backup_region | Specifies the region for executing the backup. |
| backup_zone | Specifies the zone for executing the backup. |
| log_archive_batch_buffer_limit | Controls the maximum memory usage for log archiving on a single server. |
| log_archive_checkpoint_interval | Specifies the time interval for cold data log archiving checkpoints. |
| restore_concurrency | Specifies the maximum concurrency level for restoring tenant data from a backup. |
cgroup
Parameter |
Description |
|---|---|
| enable_cgroup | Controls whether to enable the cgroup feature on OBServer nodes. |
CPU-related parameters
Parameter |
Description |
|---|---|
| cpu_count | Specifies the total number of CPU cores. If you set this parameter to 0, the system automatically detects the number of CPU cores. |
| server_balance_cpu_mem_tolerance_percent | Specifies the tolerance for CPU and memory resource imbalance in the node load balancing strategy. |
| server_cpu_quota_max | Specifies the maximum CPU quota available to the system. |
| server_cpu_quota_min | Specifies the minimum CPU quota available to the system. The system automatically reserves the quota. |
| token_reserved_percentage | Specifies the percentage of idle tokens reserved for each tenant in the CPU scheduling of a tenant. |
| workers_per_cpu_quota | Specifies the number of worker threads allocated to each CPU quota. |
| cpu_reserved | Specifies the number of CPU cores reserved for the system. The remaining CPU cores are exclusively used by OceanBase Database. |
| sys_cpu_limit_trigger | Specifies the CPU utilization threshold. If the CPU utilization exceeds this threshold, the system pauses the execution of background tasks. |
| system_cpu_quota | Specifies the CPU quota available to the system tenant. |
| tenant_cpu_variation_per_server | Specifies the allowed deviation in CPU quota scheduling among multiple units of a tenant. |
Read/write/query-related parameters
Parameter |
Description |
|---|---|
| weak_read_version_refresh_interval | Specifies the refresh cycle of the weak-consistency read version number, which affects the latency of weak-consistency read data. |
| large_query_worker_percentage | Specifies the percentage of worker threads reserved for processing large queries. |
| large_query_threshold | Specifies the threshold for query execution time. |
| trace_log_slow_query_watermark | Specifies the query execution time threshold. If the query execution time exceeds this threshold, the query is considered a slow query, and the trace log of the slow query is printed to the system log. |
Load balancing
Parameter |
Description |
|---|---|
| balancer_log_interval | Specifies the interval at which the statistics logs of the disaster recovery task threads are printed. |
| balancer_task_timeout | Specifies the timeout period for background tasks such as load balancing. |
| balancer_tolerance_percentage | Specifies the tolerance for disk imbalance between multiple Units of a tenant in the load balancing strategy. If the disk imbalance is within the range of the mean value plus or minus the tolerance, no load balancing action is triggered. |
| server_balance_critical_disk_waterlevel | Specifies the water level for disk space load balancing. |
| server_balance_disk_tolerance_percent | Specifies the tolerance for disk imbalance in the load balancing strategy between nodes. |
| resource_hard_limit | Specifies the over-provisioning percentage of CPU resources. |
| enable_sys_unit_standalone | Specifies whether to enable exclusive node allocation for the system tenant. |
| balancer_emergency_percentage | Specifies the unit load threshold. When the unit load exceeds this threshold, replica migration is allowed, and load balancing is performed even during major compactions. |
| balancer_timeout_check_interval | Specifies the interval at which the timeout of background tasks such as load balancing is checked. |
| data_copy_concurrency | Specifies the maximum number of concurrent data migration and replication tasks that can be executed in the system. |
| tenant_groups | Specifies the tenant groups used in the load balancing strategy. |
| unit_balance_resource_weight | Specifies the resource weights used in the unit load balancing strategy. This parameter is usually not manually configured. |
| resource_soft_limit | Specifies whether to enable unit load balancing. |
Replica-related
Parameter |
Description |
|---|---|
| unit_gc_wait_time | The maximum wait time for unit GC. If the wait time exceeds the maximum, the GC is forcibly triggered. |
| enable_rereplication | Specifies whether to enable automatic migration and replication of log stream replicas. |
| ls_meta_table_check_interval | Specifies the interval at which the background thread checks the DBA_OB_LS_LOCATIONS and CDB_OB_LS_LOCATIONS views. |
| sys_bkgd_migration_change_member_list_timeout | Specifies the timeout period for changing the Paxos member group during replica migration. |
| sys_bkgd_migration_retry_num | Specifies the maximum number of retries for replica migration. |
| balance_blacklist_failure_threshold | Specifies the threshold for the number of consecutive failures of background tasks such as replica migration. If the number of consecutive failures exceeds the threshold, the replica is added to the blacklist. |
| balance_blacklist_retry_interval | Specifies the retry interval for background tasks such as replica migration after they are added to the blacklist. |
| election_cpu_quota | Specifies the CPU quota allocated to background tasks related to replica election. |
| election_blacklist_interval | Specifies the interval during which a former leader cannot be elected as the leader again. |
| enable_auto_leader_switch | Specifies whether to enable automatic leader switching. |
| enable_smooth_leader_switch | Specifies whether to enable smooth leader switching. |
| global_index_build_single_replica_timeout | Specifies the timeout period for building a global index on each replica. |
| get_leader_candidate_rpc_timeout | Specifies the timeout period for internal requests to obtain leader candidates for automatic leader switching. |
| migrate_concurrency | Specifies the maximum number of concurrent internal data migrations. |
| rebuild_replica_data_lag_threshold | Specifies the threshold for the transaction log gap between the standby replica and the leader. If the gap exceeds the threshold, the replica is rebuilt. |
| server_data_copy_out_concurrency | Specifies the maximum number of concurrent data migrations from a single node. |
| server_data_copy_in_concurrency | Specifies the maximum number of concurrent data migrations to a single node. |
| replica_safe_remove_time | Specifies the safe retention period for deleted replicas. |
Cache-related parameters
Parameter |
Description |
|---|---|
| bf_cache_miss_count_threshold | Specifies the number of macroblock misses that triggers the creation of a Bloomfilter cache. |
| bf_cache_priority | Specifies the priority of the Bloom filter cache. |
| cache_wash_threshold | Specifies the capacity threshold that triggers cache cleanup. |
| fuse_row_cache_priority | Specifies the priority of the fused row cache in the cache system. |
| user_row_cache_priority | Specifies the priority of the baseline data row cache in the cache system. |
| autoinc_cache_refresh_interval | Specifies the refresh interval of the auto-increment column cache. |
| plan_cache_evict_interval | Specifies the eviction interval of the plan cache. |
| index_block_cache_priority | Specifies the priority of the metadata index microblock cache. |
| opt_tab_stat_cache_priority | Specifies the priority of the statistics cache. |
| tablet_ls_cache_priority | Specifies the priority of the tablet mapping cache. |
| user_block_cache_priority | Specifies the priority of the data block cache in the cache system. |
| index_info_block_cache_priority | Specifies the priority of the block index in the cache system. |
| index_cache_priority | Specifies the priority of the index in the cache system. |
| user_tab_col_stat_cache_priority | Specifies the priority of the statistics cache in the cache system. |
| plan_cache_high_watermark | Specifies the memory threshold occupied by the plan cache. When this threshold is exceeded, the cache is automatically evicted. |
| plan_cache_low_watermark | Specifies the memory threshold occupied by the plan cache. When this threshold is exceeded, the cache is automatically evicted. |
Partition-related
Parameter name |
Description |
|---|---|
| tablet_meta_table_check_interval | Specifies the interval at which the background thread of the DBA_OB_TABLET_REPLICAS/CDB_OB_TABLET_REPLICAS view performs inspections. |
| tablet_meta_table_scan_batch_count | Specifies the number of tablets cached in memory by the tablet meta table iterator. |
| tablet_size | Specifies the size of each tablet during parallel processing (such as major compactions and queries) in a partition. |
| auto_broadcast_location_cache_rate_limit | Specifies the maximum number of partitions whose location information changes per second that can be broadcast by each OBServer node. |
| auto_refresh_location_cache_rate_limit | Specifies the maximum number of partitions that can be automatically refreshed per second on each OBServer node. |
| enable_pg | Specifies whether to enable the partition group feature. |
| gc_wait_archive | Specifies whether to wait for all logs in a partition to be archived during partition garbage collection. |
| partition_table_check_interval | Specifies the interval at which an OBServer node deletes non-existent replicas from a partition table. |
Background execution thread-related
Parameter name |
Description |
|---|---|
| sql_net_thread_count | Specifies the number of MySQL cluster I/O threads, that is, the number of global_sql_nio_server threads. The default value of 0 indicates that the value is the same as that of the net_thread_count parameter. |
| auto_leader_switch_interval | Specifies the working interval of the background thread for automatic leader switching. |
| switchover_process_thread_count | Specifies the size of the thread pool for primary-standby database switching. |
I/O related
Parameter |
Description |
|---|---|
| sync_io_thread_count | The number of threads for synchronous I/O requests. |
| syslog_io_bandwidth_limit | The maximum disk I/O bandwidth that system logs can occupy. System logs exceeding this 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. |
| data_storage_error_tolerance_time | The maximum tolerance time for the data disk status to be set to ERROR. |
| sys_bkgd_io_high_percentage | The maximum percentage of system background I/O. |
| sys_bkgd_io_low_percentage | The minimum percentage of system background I/O. |
| user_iort_up_percentage | The threshold for user disk I/O latency. If the user disk I/O latency exceeds this threshold, system background I/O tasks will be throttled. |
| ob_esi_rpc_port | The communication port between the obesi process and the observer process. |
| enable_ob_esi_process | Whether to enable the obesi (external storage interface) process. |
| ob_esi_session_timeout | The timeout period for the obesi process to hold active session resources. |
| ob_esi_io_concurrency | The number of concurrent I/O operations for the obesi process. |
| ob_esi_syslog_level | The current log recording level for the obesi process. |
| ob_esi_max_syslog_file_count | The maximum number of log files that the obesi process can accommodate before recycling them. |
| multiblock_read_gap_size | The maximum capacity of a single I/O aggregation read block cache. |
| multiblock_read_size | The size of I/O aggregation for reading data. |
Cluster-related
Parameter name |
Description |
|---|---|
| all_server_list | Displays the addresses of all servers in the cluster. |
| cluster | Sets the name of the OceanBase cluster. |
| cluster_id | Sets the ID of the OceanBase cluster. |
| rpc_timeout | Sets the timeout for internal cluster requests. |
| all_cluster_list | Displays the list of servers that access the same config_url. |
| enable_election_group | Sets whether to enable the election group strategy. |
| local_ip | The IP address of the machine where the ObServer is installed. |
| observer_id | The unique identifier assigned to the OBServer node by the RS in the cluster. |
| min_observer_version | Displays the lowest application version number of the OBServer nodes in the cluster. |
Bandwidth-related
Parameter name |
Description |
|---|---|
| enable_ob_ratelimit | Enables rate limiting between regions in RPC connections. |
| ob_ratelimit_stat_period | Sets the interval for OBServer nodes to calculate and update the maximum bandwidth. |
Location Cache-related
Parameter name |
Description |
|---|---|
| virtual_table_location_cache_expire_time | Sets the expiration time for virtual table location information cache. |
| location_cache_refresh_rpc_timeout | The timeout for refreshing location_cache via RPC. |
| location_cache_refresh_sql_timeout | The timeout for refreshing location_cache via SQL. |
| location_cache_refresh_min_interval | Sets the minimum interval for location cache refresh requests to prevent excessive refresh requests from causing excessive system pressure. |
| location_cache_cpu_quota | Sets the CPU quota for the location cache module. |
| location_fetch_concurrency | Sets the maximum concurrency for single-machine location_cache refresh. |
| location_refresh_thread_count | Sets the number of threads for OBServer nodes to obtain partition location information from the Root Service. |
| enable_auto_refresh_location_cache | Sets whether to enable automatic refresh of location cache information. |
Directory path-related parameters
Parameter |
Description |
|---|---|
| config_additional_dir | Specifies multiple directories for storing local configuration files to ensure redundancy. |
| data_dir | Specifies the directory for storing data such as SSTables. |
Memory space related
Parameter |
Description |
|---|---|
| datafile_disk_percentage | The percentage of the total space of the disk where the data_dir directory is located. |
| data_disk_usage_limit_percentage | The maximum percentage of the disk space that can be used for data files. If this threshold is exceeded, data migration is prohibited. |
| enable_sql_operator_dump | Specifies whether to allow intermediate results of SQL processing to be written to disk to release memory. |
| global_write_halt_residual_memory | The global remaining memory threshold that triggers a pause of write operations for ordinary tenants (write operations for the sys tenant are not affected). |
| leak_mod_to_check | Used for memory leak checks. It is an internal debugging feature. |
| memory_chunk_cache_size | The size of the memory blocks cached by the memory allocator. |
| memory_limit | The total available memory size. |
| memory_limit_percentage | The percentage of the total available memory size to the total memory size. |
| memory_reserved | The memory size reserved for the KVCache. |
| memstore_limit_percentage | The percentage of the tenant's total available memory that can be used for MemStore. |
| system_memory | The memory size reserved for the tenant with tenant ID 500. |
| use_large_pages | Manages the use of large pages for database memory. |
| datafile_maxsize | The maximum size to which disk files can automatically expand. |
| datafile_next | The incremental size for disk file auto-expansion. |
| storage_meta_cache_priority | The priority of the storage Meta Cache in the KVCache. |
PX
Parameter |
Description |
|---|---|
| px_task_size | Specifies the amount of data processed by each task of the SQL parallel query engine. |
| max_px_worker_count | Specifies the maximum number of threads used by the SQL parallel query engine. |
Other
Parameter |
Description |
|---|---|
| builtin_db_data_verify_cycle | The data block verification cycle, in days. A value of 0 indicates that no verification is performed. |
| data_storage_warning_tolerance_time | The time during which the data disk is allowed to be in the WARNING state. |
| dead_socket_detection_timeout | The time interval for detecting a failed socket. |
| migration_disable_time | The maximum time during which data migration is suspended when data migration fails due to a full disk. |
| schema_history_expire_time | The time during which metadata history data is retained. |
| datafile_size | The size of a data file. This parameter is not required. |
| devname | The name of the network interface card (NIC) to which the service process is bound. |
| enable_perf_event | Specifies whether to enable the collection of performance event information. |
| enable_record_trace_id | Specifies whether to record the trace ID set by the application. |
| enable_upgrade_mode | Specifies whether to enable the upgrade mode. In the 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. A value of 0 indicates that this feature is disabled. |
| obconfig_url | The URL address of the OBConfig service. |
| rpc_port | The port number for remote access. |
| stack_size | Specifies the size of the function call stack. |
| tenant_task_queue_size | Specifies the size of the request queue for each tenant. |
| zone | Specifies the name of the zone where the node is located. This parameter is generally not required. |
| recyclebin_object_expire_time | Specifies the time at which to automatically purge expired schema objects in the recycle bin. |
| default_row_format | Specifies the default row format used when creating tables in MySQL mode. |
| sys_bkgd_net_percentage | Specifies the percentage of network bandwidth that can be occupied by background system tasks. |
| schema_history_recycle_interval | Specifies the interval at which to execute the schema multi-version record recycling task. |
| enable_asan_for_memory_context | When using ob_asan, specifies whether to allow ObAsanAllocator (the default ObAllocator) as the memory context allocator. |
| ofs_list | Stores the OceanBase File System (OFS) connection URLs for each zone. OFS is a distributed storage system designed by OceanBase Database. This parameter is mainly used in OFS deployment mode to allow RootService to access files across zones. |
Root Service
Parameter |
Description |
|---|---|
| rootservice_async_task_queue_size | Specifies the size of the internal asynchronous task queue of the Root Service. |
| rootservice_async_task_thread_count | Specifies the size of the thread pool used for internal asynchronous tasks of the Root Service. |
| rootservice_list | Displays the list of machines where the Root Service and its replicas are located. |
| rootservice_ready_check_interval | Specifies the interval at which the Root Service waits and checks the cluster status after it is started. |
| rootservice_memory_limit | Specifies the maximum memory capacity limit of the Root Service. |
| lease_time | Specifies the duration of the heartbeat lease. |
| server_check_interval | Specifies the interval at which the server table consistency is checked. |
| server_permanent_offline_time | Specifies the threshold for node heartbeat interruption. After this threshold is exceeded, the node is considered permanently offline, and data replicas on permanently offline nodes need to be automatically replenished. |
| ob_event_history_recycle_interval | Controls the interval for recycling historical events. |
| enable_rootservice_standalone | Specifies whether to allow the system tenant and RootService to exclusively use the OBServer node. |
| fast_recovery_concurrency | Controls the number of concurrent fast recovery tasks scheduled by the RootService on the OBServer node. |
| wait_leader_batch_count | Specifies the maximum number of partitions to be switched at a time for the RootService. |
RPC authentication-related parameters
Parameter |
Description |
|---|---|
| rpc_client_authentication_method | Specifies the security authentication method for the RPC client. |
| rpc_server_authentication_method | Specifies the security authentication method for the RPC server. |
SQL-related parameters
Parameter |
Description |
|---|---|
| sql_login_thread_count | Specifies the number of threads for handling SQL login requests. |
| sql_audit_memory_limit | Specifies the maximum memory that can be occupied by SQL audit data. |
| enable_sys_table_ddl | Specifies whether to allow manual creation of system tables. |
| internal_sql_execute_timeout | Specifies the time interval for internal DML requests. |
Transaction and transaction log related
Parameter |
Description |
|---|---|
| log_disk_size | Specifies the size of the redo log disk. |
| log_disk_percentage | Specifies the percentage of the total space occupied by the redo log on the disk. |
| dtl_buffer_size | Specifies 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 | Specifies the time interval for automatic retries after a two-phase commit fails. |
| standby_fetch_log_bandwidth_limit | Specifies the maximum bandwidth that can be occupied by the total log synchronization traffic from all servers in the standby tenant cluster to the primary tenant. |
| log_storage_warning_tolerance_time | Specifies the time from when a disk I/O failure occurs on the log disk to when the disk is marked as a bad disk. |
| clog_disk_utilization_threshold | Specifies the water level for reusing clog or ilog disk space. |
| clog_expire_days | Specifies the expiration time of a clog file. When the last modification time of a clog file exceeds the expiration time, the file is deleted. |
| clog_cache_priority | Specifies the priority of the transaction log cache. |
| clog_disk_usage_limit_percentage | Specifies the maximum percentage of the available disk space for transaction logs. |
| clog_sync_time_warn_threshold | Specifies the transaction log synchronization time threshold for generating a warning log. |
| clog_transport_compress_func | Specifies the compression algorithm used for internal transaction log transmission. |
| enable_one_phase_commit | Specifies whether to enable the one-phase commit optimization feature. |
| enable_separate_sys_clog | Specifies whether to store system transaction logs separately from user transaction logs. |
| flush_log_at_trx_commit | Specifies the strategy for writing transaction logs when a transaction is committed. |
| ignore_replay_checksum_error | Specifies whether to ignore checksum errors that occur during transaction log replay. |
| index_clog_cache_priority | Specifies the priority of the transaction log index in the cache system. |
| ilog_index_expire_time | Specifies the maximum time for which an OBServer node can provide Ilog files for reading. |
| trx_force_kill_threshold | Specifies the maximum waiting time for killing a transaction when it is frozen or needs to be killed due to a primary-standby switch. |
Lock related
Parameter |
Description |
|---|---|
| trx_try_wait_lock_timeout | Specifies the maximum wait time for a row lock during statement execution. |
Debugging
Parameter |
Description |
|---|---|
| debug_sync_timeout | Specifies the timeout period for the Debug Sync feature. |
| enable_rich_error_msg | Specifies whether to add debugging information, such as the server address, time, and trace ID, to client messages. |
TCP
Parameter |
Description |
|---|---|
| enable_tcp_keepalive | Specifies whether to enable the keepalive mechanism for client connections. |
| tcp_keepidle | Specifies the time interval, in seconds, after which a keepalive probe is sent to a client connection that has been idle for the specified period. |
| tcp_keepintvl | Specifies the time interval, in seconds, between two consecutive keepalive probes. |
| tcp_keepcnt | Specifies the maximum number of retries before closing an inactive client connection. |
System log-related parameters
Parameter |
Description |
|---|---|
| alert_log_level | Specifies the alert log level. |
| enable_record_trace_log | Specifies whether to record trace logs. |
| enable_async_syslog | Specifies whether to enable asynchronous system log writing. |
| enable_syslog_recycle | Specifies whether to record old logs before the OBServer node starts. This parameter, together with max_syslog_file_count, determines whether the recycling logic considers old log files. |
| enable_syslog_wf | Specifies whether to print system logs of WARN level and above to a separate log file. |
| max_string_print_length | Specifies the maximum length of a single line of system log. |
| max_syslog_file_count | Specifies the maximum number of log files that can be retained before log files are recycled. |
| syslog_level | Specifies the system log level. |
| trace_log_sampling_interval | Specifies the interval at which trace logs are periodically printed. |
| diag_syslog_per_error_limit | Specifies the maximum number of DIAG system logs that can be printed per second for each error code. If this threshold is exceeded, logs will no longer be printed. |
| enable_log_archive | Specifies whether to enable the log archiving feature. |
| system_trace_level | Specifies the log printing level for system trace logs. |
Compression algorithm-related parameters
Parameter |
Description |
|---|---|
| default_compress_func | Specifies the default compression algorithm for table data. You can also specify a different compression algorithm when creating a table. |
| default_compress | Specifies the default compression strategy for tables in Oracle mode. |
| tableapi_transport_compress_func | Specifies the compression algorithm used for transmitting query results in OBKV-Table. |
| default_transport_compress_func | Specifies the RPC compression algorithm for the entire cluster. |
Dumps and major compactions
Parameter |
Description |
|---|---|
| enable_major_freeze | Specifies whether to enable automatic global freezing. |
| micro_block_merge_verify_level | Specifies the verification level for macroblocks during compaction. |
| row_compaction_update_limit | Specifies the number of modifications required to trigger in-memory row compaction. |
| enable_global_freeze_trigger | Specifies whether to enable automatic global freezing. |
| enable_merge_by_turn | Specifies whether to enable the round-robin compaction strategy. |
| enable_manual_merge | Specifies whether to enable manual compaction. |
| global_major_freeze_residual_memory | Specifies the residual memory threshold for triggering global freezing. That is, global freezing is triggered when the residual memory is less than this percentage. |
| minor_deferred_gc_time | Specifies the interval for delayed SSTable garbage collection after compaction. |
| zone_merge_concurrency | Specifies the number of zones that can be merged concurrently. If the value is 0, the system automatically selects the optimal concurrency based on deployment. |
| zone_merge_order | Specifies the order for round-robin zone compaction. If not specified, the system automatically determines the order. |
| zone_merge_timeout | Specifies the timeout for a single zone's compaction. |
| minor_freeze_times | Specifies the number of freezes required to trigger a compaction. |
| minor_merge_concurrency | Specifies the number of concurrent threads for compaction. |
| minor_warm_up_duration_time | Specifies the pre-warm time for generating new compaction files. |
| row_purge_thread_count | Specifies the maximum number of working threads for in-memory row compaction. |
Arbitration service
Parameter |
Description |
|---|---|
| arbitration_degradation_policy | Specifies the automatic degradation strategy. |
| ob_startup_mode | Specifies the startup mode of the OBServer node, which can be modified only during the first startup. |
Resource isolation
Parameter |
Description |
|---|---|
| clog_io_isolation_mode | Specifies whether to isolate I/O requests on the clog disk based on whether the clog and data disks are independent. |
| enable_global_background_resource_isolation | Enables global foreground and background resource isolation. |
| global_background_cpu_quota | Specifies the CPU quota for background tasks when global foreground and background resource isolation is enabled. |
Tenant-level parameters
Security
Parameter name |
Description |
|---|---|
| sts_credential | Specifies the credentials for accessing the STS service provided by OCP. |
| external_kms_info | Stores key management information. |
| tde_method | Specifies the method for transparent tablespace encryption. |
| audit_sys_operations | Specifies whether to track the operations of system users. |
| audit_trail | Specifies whether to enable database auditing. |
Storage
Parameter name |
Description |
|---|---|
| default_table_organization | Specifies the default table organization mode for newly created tables. |
| default_table_merge_engine | Specifies the merge_engine for newly created tables in the user tenant.
NoteFor OceanBase Database V4.3.5, this parameter is available starting with V4.3.5 BP3. |
CPU
Parameter name |
Description |
|---|---|
| cpu_quota_concurrency | Specifies the maximum number of concurrent sessions allowed for each CPU quota for the tenant. |
Read/write and query
Parameter name |
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 refresh the information_schema.QUERY_RESPONSE_TIME view and read query_response_time_range_base again. |
| query_response_time_range_base | Specifies the interval for collecting time parameters in the information_schema.QUERY_RESPONSE_TIME view. |
Load balancing
Parameter |
Description |
|---|---|
| unit_gc_wait_time | The maximum wait time for unit garbage collection. If the wait time exceeds the maximum, garbage collection is forced. |
| balancer_idle_time | The interval at which background task threads, such as those for load balancing, are awakened when they are idle. |
| enable_rebalance | Specifies whether to enable automatic load balancing. |
| enable_transfer | Specifies whether to allow transfers within a tenant. This parameter is invalid when enable_rebalance is disabled. |
| partition_balance_schedule_interval | The scheduling cycle for partition balancing. |
Replica
Parameter |
Description |
|---|---|
| replica_parallel_migration_mode | The mode for log stream replica parallel migration. |
| choose_migration_source_policy | The priority strategy for selecting the source replica for migration. |
Backup and restore
Parameter |
Description |
|---|---|
| recover_table_concurrency | Specifies the maximum number of tables that can be restored in parallel during the cross-tenant table import phase of table-level restore. |
| recover_table_dop | Specifies the maximum number of tables that can be restored in parallel during the cross-tenant table import phase of table-level restore. |
| log_restore_concurrency | Specifies the concurrency level for log restore. |
| log_archive_concurrency | Specifies the concurrency level for log archiving. |
| backup_data_file_size | Specifies the maximum size of a single data backup file. |
Partition
Parameter |
Description |
|---|---|
| enable_auto_split | Specifies whether to enable automatic partitioning for a tenant. The default value is OFF. |
| auto_split_tablet_size | The threshold for triggering a split when automatic partitioning is enabled for a tenant. The default value is 128 MB. |
| global_index_auto_split_policy | Specifies whether to enable automatic partitioning for newly created global indexes. The default value is DISTRIBUTED. |
Background execution threads
Parameter |
Description |
|---|---|
| ddl_thread_score | Specifies the number of threads used for DDL operations. |
| compaction_low_thread_score | Specifies the number of threads for low-priority major compactions. |
| compaction_high_thread_score | Specifies the number of threads for high-priority major compactions. |
| compaction_mid_thread_score | Specifies the number of threads for medium-priority major compactions. |
| ha_high_thread_score | Specifies the number of threads for high-priority HA operations. |
| ha_mid_thread_score | Specifies the number of threads for medium-priority HA operations. |
| ha_low_thread_score | Specifies the number of threads for low-priority HA operations. |
| ob_compaction_schedule_interval | Specifies the time interval for major compaction scheduling. |
| compaction_dag_cnt_limit | Specifies the maximum number of DAGs in the Compaction DAG queue. |
| compaction_schedule_tablet_batch_cnt | Specifies the maximum number of partitions scheduled in each batch during major compaction. |
| tenant_sql_login_thread_count | Specifies the number of threads for MySQL tenant login, i.e., the number of mysql_queue threads. The default value of 0 indicates that the value of unit_min_cpu is used. |
| tenant_sql_net_thread_count | Specifies the number of I/O threads for MySQL tenants, i.e., the number of sql_nio_server threads. The default value of 0 indicates that the value of unit_min_cpu is used. |
Cache
Parameter |
Description |
|---|---|
| default_storage_cache_policy | Specifies the default cache strategy. |
| enable_manual_storage_cache_policy | Enables the user-defined hot cache strategy. |
| suspend_storage_cache_task | Specifies whether to suspend background cache tasks. |
| enable_adaptive_plan_cache | Specifies whether to enable the adaptive plan cache (Plan Cache) feature for the tenant. |
| result_cache_max_size | Specifies the maximum memory size that can be used by the result cache module. |
| result_cache_max_result | Specifies the maximum proportion of result_cache_max_size that can be used by a single result cache cache object. |
| ob_result_cache_evict_percentage | Specifies the memory eviction threshold for result cache. |
| ob_deterministic_udf_cache_max_size | Specifies the maximum memory size that can be used by the cache pool for all deterministic UDFs during statement execution. |
I/O related parameters
Parameter name |
Description |
|---|---|
| io_category_config | Configure the percentages of I/O requests of various categories. |
Compatible with
Note
Parameters in the following table take effect only in MySQL mode.
Parameter |
Description |
|---|---|
| enable_sql_extension | Enables or disables the SQL extension feature for the tenant. |
| compatible | This parameter specifies the compatibility mode of the tenant. The value cannot be set. |
Routing
Parameter name |
Description |
|---|---|
| ob_proxy_readonly_transaction_routing_policy | Controls whether the Proxy is affected by read-only statements during transaction routing. |
LOB data
Parameter Name |
Description |
|---|---|
| lob_enable_block_cache_threshold | Specifies the threshold for LOB block cache enabled for OUTROW storage. |
Memory-related parameters
Parameter name |
Description |
|---|---|
| ob_vector_memory_limit_percentage | Specifies the threshold for memory usage by the vector index module. The unit is percentage. |
| range_optimizer_max_mem_size | Specifies the maximum amount of memory that can be used by the Query Range module. |
| rpc_memory_limit_percentage | The percentage of total memory occupied by the maximum memory allocated to RPC calls in a tenant. |
| query_memory_limit_percentage | Specify the maximum percentage of tenant memory that can be used for each SQL statement. |
Disk space
| Parameter | Description | Type | Default value | Value range | Modifiable | Effective upon OBServer node restart | | --- | --- | --- | --- | --- | --- | --- | | disk_encryption_config | The encryption method of a disk. Valid values: * AES-NI: the AES-NI mode of the AES-128 encryption algorithm. * AES-256: the AES-256 encryption algorithm. | VARCHAR(256) | AES-NI | The value is one of the two valid values listed in this table. | Yes, the parameter can be modified through the ALTER SYSTEM SET statement. | No. The setting takes effect immediately. | | disk_encryption_password | The password for encrypting a disk. | VARCHAR(256) | "" (empty string) | The value is a string of no more than 256 characters. | Yes, the parameter can be modified through the ALTER SYSTEM SET statement. | No. The setting takes effect immediately. | | max_disk_used_ratio | The maximum percentage of occupied disk space of an OBServer node. A value of 100 indicates that no disk space is available. | INT | 85 | The value is an integer in the range [0, 100]. | Yes, the parameter can be modified through the ALTER SYSTEM SET statement. | No. The setting takes effect immediately. | | minor_free_space | The minimum free space of each OBServer node. The unit is MB. | INT | 512 | The value is an integer in the range [1, 1024]. | Yes, the parameter can be modified through the ALTER SYSTEM SET statement. | No. The setting takes effect immediately. | | max_disk_per_server | The maximum number of disks that can be mounted to an OBServer node. | INT | 2 | The value is an integer in the range [1, 1024]. | Yes, the parameter can be modified through the ALTER SYSTEM SET statement. | No. The setting takes effect immediately. | | disk_size | The total size of disks of an OBServer node. The unit is GB. | INT | 1 | The value is an integer in the range [1, 1024]. | Yes, the parameter can be modified through the ALTER SYSTEM SET statement. | No. The setting takes effect immediately. | | max_disk_used_space | The maximum size of disk space used by an OBServer node. The unit is GB. | INT | 0 | The value is an integer in the range [0, 1024]. | Yes, the parameter can be modified through the ALTER SYSTEM SET statement. | No. The setting takes effect immediately. | | disk_num | The number of disks of an OBServer node. | INT | 1 | The value is an integer in the range [1, 1024]. | Yes, the parameter can be modified through the ALTER SYSTEM SET statement. | No. The setting takes effect immediately. | You can query the parameters for a cluster by running the SHOW PARAMETERS statement. You can also modify the parameters by using the ALTER SYSTEM SET statement. For more information about these parameters, see the following topics:
OBKV related
Parameter name |
Description |
|---|---|
| enable_kv_ttl | Specifies whether to enable the TTL background task. This parameter is applicable to periodic TTL tasks. It does not affect the execution of tenant management commands. Note: The TTL feature is applicable only to the OceanBase KV scenario and is disabled in SQL scenarios to prevent unintended data deletion. |
| kv_ttl_duty_duration | Sets the period for triggering the daily scheduled TTL operation. This TTL operation is triggered once during this period. |
| kv_group_commit_batch_size | Specifies the batch size of a group commit operation in OBKV. |
| kv_group_commit_rw_mode | Configures the read/write mode for group commits. |
| kv_hbase_client_scanner_timeout_period | Specify the timeout period for a streaming query. |
| kv_ttl_history_recycle_interval | The time period for which history records of TTL tasks are retained. |
| ttl_thread_score | Sets the number of worker threads used for TTL tasks. |
PL/SQL
Parameter name |
Description |
|---|---|
| plsql_code_type | Specifies the compilation type of PL/SQL code. |
| plsql_debug | Specifies whether to compile the code into a debug version. |
| plsql_optimize_level | Specifies the compilation optimization level. |
| plsql_v2_compatibility | Controls whether to enable the compilation and persistence of DDL operations for stored procedures. |
| package_state_sync_max_size | Controls the maximum length of a package state that can be serialized. |
Direct load
Parameter name |
Description |
|---|---|
| default_load_mode | Specifies the data import mode in data import scenarios. |
| direct_load_allow_fallback | Specifies whether to fall back to standard import when direct load is not supported in a specified direct load operation. |
Others
Parameter |
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 the SQL work area. |
| open_cursors | Limits the number of cursors that can be opened simultaneously in a single session. |
| ob_ssl_invited_common_names | Records the list of application identities for the current tenant, which are obtained from the cn field (common name) in the subject of the client certificate during SSL mutual authentication. |
| ob_enable_batched_multi_statement | Specifies whether to enable the batched multi-statement execution optimization. |
| job_queue_processes | Specifies the maximum number of concurrent tasks that can be run on each tenant to prevent resource contention. |
| default_auto_increment_mode | Specifies the default auto-increment mode for columns. |
| ob_query_switch_leader_retry_timeout | Specifies the maximum retry time for failed queries, in microseconds (us). |
| default_enable_extended_rowid | Specifies whether to create tables in Extended ROWID mode. |
| dump_data_dictionary_to_log_interval | Controls the persistence cycle of the tenant data dictionary. |
| enable_user_defined_rewrite_rules | Controls whether to enable user-defined rewrite rules. |
| storage_rowsets_size | Controls the number of rows processed in a single vectorized batch for the columnar engine. |
| approx_count_distinct_precision | Configures the result precision of the approx_count_distinct function. |
| enable_ps_parameterize | Controls whether to parameterize PS statements during parsing. |
| default_skip_index_level | Controls the mechanism for generating Skip Indexes in incremental SSTables for the tenant. |
Transaction and transaction log parameters
Parameter name |
Description |
|---|---|
| log_disk_utilization_limit_threshold | This parameter specifies the utilization threshold of log disk storage space at the tenant level. Once the log disk utilization of the tenant exceeds this threshold, log write operations are prohibited. |
| log_disk_utilization_threshold | The log disk utilization threshold for tenants. When the tenant log disk usage exceeds this threshold, log files are reused. |
| writing_throttling_maximum_duration | Specifies the time required for the remaining MemStore memory to be fully allocated after write throttling is triggered. In other words, this parameter specifies the maximum duration for which write throttling is applied. |
| writing_throttling_trigger_percentage | Specifies the write-throughput threshold. |
| standby_db_fetch_log_rpc_timeout | The maximum time allowed for the standby database to fetch logs from the primary database. It controls the service to detect an unavailable server of the primary database and switch the server to a new one. |
| log_disk_throttling_percentage | The percentage of non-reclaimable log disk space that triggers throttling of log writes. |
| log_transport_compress_all | Indicates whether to use compression for log transport. |
| log_transport_compress_func | The compressor for log transmission. |
| clog_max_unconfirmed_log_count | The maximum number of unconfirmed logs in the transaction module. |
| clog_persistence_compress_func | Specifies the compression algorithm for persisting transaction logs. |
| enable_clog_persistence_compress | Whether to enable transaction log persistence compression. |
Data types
Parameter |
Description |
|---|---|
| json_document_max_depth | This parameter specifies the maximum number of allowed nesting levels of a JSON document. |
Lock-related
Parameter |
Description |
|---|---|
| enable_lock_priority | The lock priority switch. |
System logs
Parameter |
Description |
|---|---|
| log_disk_throttling_maximum_duration | This parameter specifies the maximum time during which log disks are available after log throttling is triggered. |
| ls_gc_delay_time | The time during which a log stream in the current tenant will be delay-deleted. |
| standby_db_preferred_upstream_log_region | Configures the preferred log synchronization region for standby tenants. |
| archive_lag_target | The value determines the amount of time for which to retain logs in the tenant. |
Materialized views
Parameter |
Description |
|---|---|
| enable_mlog_auto_maintenance | Specifies whether to enable the automatic maintenance feature for materialized view logs.
NoteFor V4.3.5, this parameter is available starting with V4.3.5 BP4. |
| mlog_trim_interval | Specifies the scheduling cycle for the background automatic trimming task of materialized view logs (mlogs).
NoteFor V4.3.5, this parameter is available starting with V4.3.5 BP4. |
| enable_mv_binlog_minimal_mode | Specifies whether to enable the minimal mode for materialized views.
NoteFor V4.3.5, this parameter is available starting with V4.3.5 BP5. |
User login
Note
The following parameters are effective only in MySQL mode.
Parameter |
Description |
|---|---|
| connection_control_failed_connections_threshold | Specifies the threshold for failed login attempts. |
| connection_control_min_connection_delay | Specifies the minimum lock duration after the threshold for failed login attempts is exceeded. |
| connection_control_max_connection_delay | Specifies the maximum lock duration for failed login attempts. The lock duration will not increase beyond this value. |
Compression algorithms
Parameter |
Description |
|---|---|
| spill_compression_codec | Specifies the compression algorithm for data spilling during SQL execution. |
| ob_encoding_granularity | Specifies the maximum number of rows in a microblock encoding. |
Dumps and major compactions
Parameter |
Description |
|---|---|
| default_progressive_merge_num | Specifies the default number of progressive major compactions for a new table. |
| major_freeze_duty_time | Specifies the time at which to trigger daily major compactions. |
| major_compact_trigger | Specifies the number of major compactions to trigger. |
| minor_compact_trigger | Specifies the number of SSTables to trigger a minor compaction. |
| undo_retention | Specifies the range of data versions to be retained in the system, in seconds. During a major compaction, the system recycles data versions based on this parameter. |
| merger_check_interval | Specifies the interval at which to check the status of major compactions. |
| freeze_trigger_percentage | Specifies the memory usage threshold of a tenant that triggers a global major compaction. |
| max_kept_major_version_number | Specifies the number of major compaction versions to be retained. |
| merge_stat_sampling_ratio | Specifies the sampling rate of data column statistics during a major compaction. |
| merge_thread_count | Specifies the number of threads for daily major compactions. |
| merger_completion_percentage | Specifies the percentage of replicas that are completed in a major compaction. When this threshold is reached, the current major compaction is considered complete. |
| merger_switch_leader_duration_time | Specifies the interval at which to batch switch leaders during daily major compactions. |
| merger_warm_up_duration_time | Specifies the warm-up time for new baseline data during a major compaction. |
Arbitration service
Parameter |
Description |
|---|---|
| arbitration_timeout | Specifies the timeout period for automatic downgrade. |
Unsupported parameters
Parameter |
Description |
|---|---|
| sql_work_area | Specifies the tenant working area memory. |
| max_stale_time_for_weak_consistency | Specifies the maximum number of versions that can be read in a weak-consistency read. |