This topic lists the cluster-level parameters and tenant-level parameters of OceanBase Database.
Cluster-level parameters
Security parameters
| Parameter | Description |
|---|---|
| mysql_port | The port number for the SQL service protocol. |
| rpc_port | The remote procedure call (RPC) port. |
| sql_protocol_min_tls_version | The minimum version of the SSL/TLS protocol used by SSL connections for SQL statements. |
| ssl_client_authentication | Specifies whether to enable SSL authentication. |
| ssl_external_kms_info | The information that the SSL feature of OceanBase Database relies on, which is recorded in JSON strings for different SSL modes. Such a JSON string contains at least the ssl_mode field. |
| enable_sql_audit | Specifies whether to enable SQL audit. |
Backup and restore parameters
| Parameter | Description |
|---|---|
| backup_backup_dest | The destination for second backup. |
| backup_backup_dest_option | The parameters for second backup. |
| backup_dest_option | The parameters for backup. |
| backup_concurrency | The concurrency of data writes to the file system during backup. |
| backup_dest | The path for baseline data backup and log archiving. |
| backup_log_archive_option | The options for log archiving during backup. |
| backup_net_limit | The total bandwidth for cluster backup. |
| backup_recovery_window | The time window in which backups can be recovered. |
| backup_region | The region for which backup tasks are run. |
| backup_zone | The zone for which backup tasks are run. |
| log_archive_batch_buffer_limit | The maximum memory available for log archiving on a single server. |
| log_archive_checkpoint_interval | The interval between log archiving checkpoints of cold data. |
| restore_concurrency | The maximum concurrency of tenant data recovery from backups. |
Cgroup parameters
| Parameter | Description |
|---|---|
| enable_cgroup | Specifies whether to enable the control group (cgroup) feature for the OBServer node. |
CPU parameters
| Parameter | Description |
|---|---|
| cpu_count | The total number of CPU cores in the system. If the parameter is set to 0, the system will automatically detect the number of CPU cores. |
| server_balance_cpu_mem_tolerance_percent | The tolerance of CPU and memory resource imbalance in the node load balancing strategy. |
| server_cpu_quota_max | The maximum CPU quota for the system. |
| server_cpu_quota_min | The minimum CPU quota for the system. The system automatically reserves the quota. |
| token_reserved_percentage | The percentage of idle tokens reserved for tenants in the scheduling of CPU resources for the tenants. |
| workers_per_cpu_quota | The number of worker threads allocated to each CPU quota. |
| cpu_reserved | The number of CPUs reserved in the system. The remaining CPUs are exclusively occupied by OceanBase Database. |
| sys_cpu_limit_trigger | The CPU utilization threshold. When CPU utilization reaches the threshold, backend tasks in the system will be suspended. |
| system_cpu_quota | The CPU quota for the sys tenant. |
| tenant_cpu_variation_per_server | The variation allowed for CPU quota scheduling among multiple units of a tenant. |
Read/Write and query parameters
| Parameter | Description |
|---|---|
| weak_read_version_refresh_interval | The version refresh interval for weak consistency reads. This parameter affects the latency of weak consistency reads. |
| large_query_worker_percentage | The percentage of worker threads reserved for large queries. |
| large_query_threshold | The execution time threshold to identify a large query. |
| trace_log_slow_query_watermark | The execution time threshold to identify a slow query. Trace logs of slow queries are written to system logs. |
Load balancing parameters
| Parameter | Description |
|---|---|
| balancer_log_interval | The interval for printing statistical logs generated by the threads of backend tasks such as load balancing. |
| balancer_task_timeout | The timeout period of backend tasks such as load balancing. |
| balancer_tolerance_percentage | The tolerance for disk imbalance among multiple units of a tenant, which is set in the load balancing strategy. If the imbalance is within the range that starts at the average value minus the tolerance and ends at the average value plus the tolerance, no balancing action is triggered. |
| server_balance_critical_disk_waterlevel | The disk usage threshold that triggers disk load balancing. |
| server_balance_disk_tolerance_percent | The tolerance for disk load imbalance among nodes, which is set in the load balancing strategy. |
| resource_hard_limit | The over-allocation percentage of CPU resources. |
| enable_sys_unit_standalone | Specifies whether the unit of the sys tenant exclusively occupies a node. |
| balancer_emergency_percentage | The load threshold of each unit. When the load of a unit exceeds the specified threshold, you can enable replica migration to an external system for load balancing even during a major compaction. |
| balancer_timeout_check_interval | The interval for checking whether backend tasks such as load balancing time out. |
| data_copy_concurrency | The maximum concurrency for data migration and replication in the system. |
| tenant_groups | The tenant groups used in the load balancing strategy. |
| unit_balance_resource_weight | The resource weight used in the unit balancing strategy. Generally, you do not need to set this parameter. |
| resource_soft_limit | Specifies whether to enable unit balancing. |
Replica parameters
| Parameter | Description |
|---|---|
| enable_rereplication | Specifies whether to enable automatic data synchronization to replicas. |
| ls_meta_table_check_interval | The interval at which the background inspection threads inspect the DBA_OB_LS_LOCATIONS or CDB_OB_LS_LOCATIONS view. |
| sys_bkgd_migration_change_member_list_timeout | The timeout period for modifying the Paxos member list during replica migration. |
| sys_bkgd_migration_retry_num | The maximum number of retries after a replica migration task fails. |
| balance_blacklist_failure_threshold | The maximum number of consecutive failures of a backend task such as replica migration. upon which the task is added to the blocklist. |
| balance_blacklist_retry_interval | The retry interval for a backend task such as replica migration that is added to the blacklist. |
| election_cpu_quota | The CPU quota allocated to backend tasks related to replica election. |
| election_blacklist_interval | The interval during which the dismissed leader cannot be re-elected as the leader. |
| enable_auto_leader_switch | Specifies whether to enable automatic leader switchover. |
| enable_smooth_leader_switch | Specifies whether to enable smooth switchover to the leader. |
| global_index_build_single_replica_timeout | The timeout period for creating a replica during global index creation. |
| get_leader_candidate_rpc_timeout | The timeout period of an internal request for obtaining the leader candidate in the automatic leader switchover strategy. |
| migrate_concurrency | The maximum concurrency for internal data migration. |
| rebuild_replica_data_lag_threshold | The threshold of the size difference of transaction logs between the leader and a follower. When the difference reaches the threshold, replica reconstruction is triggered. |
| server_data_copy_out_concurrency | The maximum concurrency for data migration from a single node. |
| server_data_copy_in_concurrency | The maximum concurrency for data migration to a single node. |
| replica_safe_remove_time | The retention period of a deleted replica before it can be cleared. |
Cache parameters
| Parameter | Description |
|---|---|
| bf_cache_miss_count_threshold | The number of macroblock misses that triggers the creation of the Bloom filter cache. |
| bf_cache_priority | The priority of the Bloom filter cache. |
| cache_wash_threshold | The remaining 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 for the auto-increment column cache. |
| plan_cache_evict_interval | The eviction interval for the execution plan cache. |
| index_block_cache_priority | The priority of the microblock cache for metadata indexes. |
| 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. |
| index_info_block_cache_priority | The priority of the block index in the cache system. |
| index_cache_priority | The priority of the index cache in the cache system. |
| user_tab_col_stat_cache_priority | The priority of the statistics cache in the cache system. |
| plan_cache_high_watermark | The memory threshold to trigger plan cache eviction. Automatic eviction is triggered when the memory occupied by the plan cache reaches the specified threshold. |
| plan_cache_low_watermark | The memory threshold to stop plan cache eviction. The eviction is stopped when the memory occupied by the plan cache decreases to the specified threshold. |
Partition parameters
| Parameter | Description |
|---|---|
| tablet_meta_table_check_interval | The interval at which the background inspection threads inspect the DBA_OB_TABLET_REPLICAS or CDB_OB_TABLET_REPLICAS view. |
| tablet_meta_table_scan_batch_count | The number of tablets cached in memory when the tablet meta table iterator is working. |
| tablet_size | The size of each shard during intra-partition parallel processing such as parallel compactions and queries. |
| auto_broadcast_location_cache_rate_limit | The maximum number of partitions whose location changes can be broadcast on each OBServer per second. |
| auto_refresh_location_cache_rate_limit | The maximum number of partitions that can be automatically refreshed on each OBServer at a time. |
| enable_pg | Specifies whether to enable the partition group feature. |
| gc_wait_archive | Specifies whether to start garbage collection for a partition until all the logs in the partition have been archived. |
| partition_table_check_interval | The interval at which OBServer deletes non-existent replicas from a partitioned table. |
Background execution thread parameters
| Parameter | Description |
|---|---|
| sql_net_thread_count | The number of I/O threads for the MySQL cluster, that is, the number of global_sql_nio_server threads. The default value 0 indicates that the value of the parameter is the same as that of net_thread_count. |
| auto_leader_switch_interval | The working interval of the backend thread for automatic leader switchover. |
| switchover_process_thread_count | The size of the thread pool for primary/standby cluster switchover. |
I/O parameters
| Parameter | Description |
|---|---|
| rdma_io_thread_count | The number of RDMA I/O threads for Libeasy. |
| syslog_io_bandwidth_limit | The maximum I/O bandwidth available for system logs. If this value is reached, the remaining system logs are discarded. |
| disk_io_thread_count | The number of disk I/O threads. The value must be an even number. |
| net_thread_count | The number of network I/O threads. |
| data_storage_error_tolerance_time | The tolerance period after which the status of an abnormal data disk is set to ERROR. |
| sys_bkgd_io_high_percentage | The highest percentage of disk bandwidth that can be used by backend I/O operations. |
| sys_bkgd_io_low_percentage | The lowest percentage of traffic for backend I/O operations. |
| user_iort_up_percentage | The I/O latency threshold for the user disk. When the I/O latency of the user disk reaches this threshold, the traffic of backend I/O operations will be throttled. |
| ob_esi_rpc_port | The communication port between the obesi process and the observer process. |
| enable_ob_esi_process | Specifies whether to enable the obesi process (external storage API). |
| ob_esi_session_timeout | The timeout period of the active session resources for the obesi process. |
| ob_esi_io_concurrency | The I/O concurrency for the obesi process. |
| ob_esi_syslog_level | The current log level for the obesi process. |
| ob_esi_max_syslog_file_count | The maximum number of log files that can be retained for the obesi process. |
| multiblock_read_gap_size | The size of multiple block caches from which data can be read in one I/O operation. |
| multiblock_read_size | The I/O aggregate throughput in data access. |
Cluster parameters
| Parameter | Description |
|---|---|
| all_server_list | The IP addresses of all servers in the cluster. |
| cluster | The name of the current OceanBase cluster. |
| cluster_id | The ID of the current OceanBase cluster. |
| rpc_timeout | The timeout period of an internal request in the cluster. |
| all_cluster_list | The list of servers that access the same URL specified for config_url. |
| enable_election_group | Specifies whether to enable the election group strategy. |
| local_ip | The IP address of the server where OceanBase Database is installed. |
| observer_id | The unique identifier that RootService assigns to the OBServer node in the cluster. |
| min_observer_version | The earliest OBServer node version in the cluster. |
Bandwidth parameters
| Parameter | Description |
|---|---|
| enable_ob_ratelimit | Specifies whether to enable rate limiting between regions in an RPC connection. |
| ob_ratelimit_stat_period | The time interval at which an OBServer node calculates and updates the maximum bandwidth. |
Location cache parameters
| Parameter | Description |
|---|---|
| virtual_table_location_cache_expire_time | The validity period of the location cache of the virtual table. |
| location_cache_refresh_rpc_timeout | The timeout period for refreshing the location cache through RPC. |
| location_cache_refresh_sql_timeout | The timeout period for refreshing the location cache through SQL. |
| location_cache_refresh_min_interval | The minimum interval for sending location cache refresh requests, which prevents excessive refresh requests from overloading the system. |
| location_cache_cpu_quota | The CPU quota for the location cache module. |
| location_fetch_concurrency | The maximum number of concurrent requests for refreshing the location cache on a single server. |
| location_refresh_thread_count | The number of threads used by the OBServer node to obtain partition location information from RootService. |
| enable_auto_refresh_location_cache | Specifies whether to enable automatic refresh of the location cache. |
Directory parameters
| Parameter | Description |
|---|---|
| config_additional_dir | The local directories for storing multiple copies of configuration files for redundancy. |
| data_dir | The directory for storing SSTables and other data. |
Memory parameters
| Parameter | Description |
|---|---|
| datafile_disk_percentage | The percentage of used space to the total space of the disk where the data_dir directory is located. This disk will be initialized for data storage by the OceanBase Database system. |
| data_disk_usage_limit_percentage | The percentage of data write space to the total space of the disk. When the data write space reaches the threshold, data can no longer be written to the disk. |
| enable_sql_operator_dump | Specifies whether to allow intermediate SQL processing results to be written to the disk to release the memory. |
| global_write_halt_residual_memory | The global available memory threshold that triggers the suspension of write operations of user tenants. (The sys tenant is not affected.) |
| leak_mod_to_check | The internal debugging feature used for memory leakage check. |
| memory_chunk_cache_size | The total cache size of the memory allocator. |
| memory_limit | The total size of available memory. |
| memory_limit_percentage | The percentage of available memory to total memory in the system. |
| memory_reserved | The memory size reserved by the system for the KV cache. |
| memstore_limit_percentage | The percentage of the memory that can be occupied by the MemStore to the total available memory of a tenant. |
| system_memory | The memory size reserved by the system for the sys500 tenant. |
| use_large_pages | Manages the use of large memory pages by the database. |
| datafile_maxsize | The maximum space allowed in automatic scaling for disk files. |
| datafile_next | The step size of automatic scaling for disk files. |
| storage_meta_cache_priority | The priority of the storage meta cache in KVCache. |
PX parameters
| Parameter | Description |
|---|---|
| px_workers_per_cpu_quota | The proportion of Parallel eXecution (PX) worker threads. |
| px_task_size | The amount of data processed by the SQL parallel query engine in each task. |
| max_px_worker_count | The maximum number of threads for the SQL parallel query engine. |
Other parameters
| Parameter | Description |
|---|---|
| builtin_db_data_verify_cycle | The cycle of a bad block check in the unit of days. When the value is set to 0, bad block checks are not performed. |
| data_storage_warning_tolerance_time | The tolerance period after which the data disk is set to the WARNING state. |
| dead_socket_detection_timeout | The interval for detecting invalid sockets. |
| migration_disable_time | The period during which data migration is suspended for a node after data migration to the node fails due to reasons such as full disk usage. |
| schema_history_expire_time | The validity period of history metadata. |
| datafile_size | The size of a data file. This parameter is generally left unspecified. |
| devname | The name of the network interface card (NIC) to which the service process is bound. |
| enable_perf_event | Specifies whether to enable the information collection feature for performance events. |
| enable_record_trace_id | Specifies whether to record the trace ID configured by the application. |
| enable_upgrade_mode | Specifies whether to enable the upgrade mode. In upgrade mode, some backend system features are suspended. |
| enable_ddl | Specifies whether to allow the execution of DDL statements. |
| high_priority_net_thread_count | The number of network threads with a high priority. When this parameter is set to 0, this feature is disabled. |
| obconfig_url | The URL of the OBConfig service. |
| rpc_port | The RPC port. |
| stack_size | The size of the function call stack for programs. |
| tenant_task_queue_size | The request queue size of each tenant. |
| zone | The name of the zone where the node is located. This parameter is generally left unspecified. |
| recyclebin_object_expire_time | The period during which a schema object can be retained in the recycle bin. After the period elapses, the object will be purged from the recycle bin. |
| default_row_format | The default row format used in table creation in MySQL mode. |
| sys_bkgd_net_percentage | The maximum percentage of network bandwidth for backend system tasks. |
| schema_history_recycle_interval | The interval for recycling schema multi-version history files. |
| enable_asan_for_memory_context | Specifies whether to enable ObAsanAllocator when ob_asan is working. By default, ObAllocator is the allocator of MemoryContext. |
| ofs_list | The list of URLs for connecting to the OceanBase File System (OFS) of all the zones so that RootService can access files across zones in OFS deployment mode. OFS is a distributed storage system independently designed for OceanBase Database. |
RootService parameters
| Parameter | Description |
|---|---|
| rootservice_async_task_queue_size | The size of the internal asynchronous task queue for RootService. |
| rootservice_async_task_thread_count | The size of the thread pool for internal asynchronous tasks of RootService. |
| rootservice_list | The list of servers where the RootService and its replicas are deployed. |
| rootservice_ready_check_interval | The wait time after the RootService is started, during which the cluster status is checked. |
| rootservice_memory_limit | The maximum memory available to RootService. |
| lease_time | The heartbeat lease period. |
| server_check_interval | The interval at which the server checks the table consistency. |
| server_permanent_offline_time | The time threshold for heartbeat missing at which a server is considered permanently offline. Data replicas on a permanently offline server must be automatically supplemented. |
| ob_event_history_recycle_interval | The interval at which historical events are recycled. |
| enable_rootservice_standalone | Specifies whether to allow the sys tenant and RootService to exclusively occupy an OBServer node. |
| fast_recovery_concurrency | The maximum concurrency for executing fast recovery tasks scheduled by RootService on an OBServer. |
| wait_leader_batch_count | The maximum number of partitions to which RootService can send a command for leader switchover. |
RPC authentication parameters
| Parameter | Description |
|---|---|
| rpc_client_authentication_method | The security authentication method of the RPC client. |
| rpc_server_authentication_method | The security authentication method of the RPC server. |
SQL request parameters
| Parameter | Description |
|---|---|
| sql_login_thread_count | The number of threads for processing SQL logon requests. |
| sql_audit_memory_limit | The maximum memory available for SQL audit data. |
| enable_sys_table_ddl | Specifies whether to enable manual creation of system tables. |
| internal_sql_execute_timeout | The interval of DML requests in the system. |
Transaction and transaction log parameters
| Parameter | Description |
|---|---|
| log_disk_size | The size of the log disk where the REDO logs are stored. |
| log_disk_percentage | The percentage of the total disk space occupied by REDO logs. |
| dtl_buffer_size | The size of the cache allocated to the SQL data transmission module. |
| ignore_replay_checksum_error | Specifies whether to ignore checksum errors that occur during transaction log playback. |
| trx_2pc_retry_interval | The interval for retrying a failed two-phase commit task. |
| standby_fetch_log_bandwidth_limit | The maximum bandwidth per second available for the total traffic of synchronizing logs from the primary tenant by all servers in the cluster where the standby tenant resides. |
| log_storage_warning_tolerance_time | The maximum duration of I/O failures tolerable on the log disk before the log disk is considered damaged and follower-to-leader switchover is triggered. |
| clog_disk_utilization_threshold | The usage of the clog or ilog disk space that triggers log file reuse. |
| clog_expire_days | The retention period of clog files. When the retention period of a clog file expires, it will be deleted. |
| clog_cache_priority | The caching priority of transaction logs. |
| clog_disk_usage_limit_percentage | The maximum percentage of disk space available for transaction logs. |
| clog_sync_time_warn_threshold | The warning threshold of time consumed for synchronizing transaction logs. When the consumed time reaches the threshold, a WARN-level log is generated. |
| clog_transport_compress_func | The algorithm for compressing transaction logs for internal transmission. |
| enable_one_phase_commit | Specifies whether to enable one-phase commit. |
| enable_separate_sys_clog | Specifies whether to separately store system transaction logs and user transaction logs. |
| flush_log_at_trx_commit | The transaction log write strategy adopted when transactions are committed. |
| ignore_replay_checksum_error | Specifies whether to ignore checksum errors that occur during transaction log playback. |
| index_clog_cache_priority | The priority of the transaction log index in the cache system. |
| ilog_index_expire_time | The validity period of ilog files on OBServers. Expired files can no longer be read. |
| trx_force_kill_threshold | The maximum amount of time that the system waits before killing transactions for a freeze or leader switchover. |
Lock parameters
| Parameter | Description |
|---|---|
| trx_try_wait_lock_timeout | The maximum amount of time that a statement waits for a locked row to be unlocked. |
Debugging parameters
| Parameter | Description |
|---|---|
| debug_sync_timeout | The timeout period for a Debug Sync operation. When the value is set to 0, Debug Sync is disabled. |
| enable_rich_error_msg | Specifies whether to add debugging information, such as the server address, error time, and trace ID, to the client message. |
TCP parameters
| Parameter | Description |
|---|---|
| enable_tcp_keepalive | Specifies whether to enable the keepalive mechanism for client connections. |
| tcp_keepidle | The interval in seconds before sending a keepalive probe packet when no data is sent on a client connection. |
| tcp_keepintvl | The interval between two probes in seconds when you enable the keepalive mechanism for client connections. |
| tcp_keepcnt | The maximum number of retries before terminating a non-active connection. |
System log parameters
| Parameter | Description |
|---|---|
| enable_record_trace_log | Specifies whether to record trace logs. |
| enable_async_syslog | Specifies whether to enable asynchronous writing of system logs. |
| enable_syslog_recycle | Specifies whether to enable recycling for system logs. |
| enable_syslog_wf | Specifies whether to print system logs above the WARN level to a separate log file. |
| max_string_print_length | The maximum length of a single row when system logs are printed. |
| max_syslog_file_count | The maximum number of log files that can be retained. |
| syslog_level | The level of syslogs. |
| trace_log_sampling_interval | The interval at which trace logs are printed. |
| diag_syslog_per_error_limit | The number of DIAG system logs allowed for each error code per second. When this threshold is reached, no more logs will be printed. |
| enable_log_archive | Specifies whether to enable log archiving. |
| system_trace_level | The level of system trace logs to be printed. |
Compression algorithm parameters
| Parameter | Description |
|---|---|
| default_compress_func | The default algorithm for compressing table data. You can also specify another compression algorithm when creating a table. |
| default_compress | The default compression strategy used during table creation in Oracle mode. |
| tableapi_transport_compress_func | The algorithm for compressing TableAPI query results for transmission. |
| default_transport_compress_func | The RPC compression algorithm used for the entire cluster. |
Minor and major compaction parameters
| Parameter | Description |
|---|---|
| enable_major_freeze | Specifies whether to enable automatic global freezing. |
| micro_block_merge_verify_level | The verification level of macroblocks in a major compaction. |
| row_compaction_update_limit | The number of data updates that triggers a major compaction of rows in the memory. |
| enable_global_freeze_trigger | Specifies whether to enable automatic triggering of a global freeze. |
| enable_merge_by_turn | Specifies whether to enable the rotating major compaction strategy. |
| enable_manual_merge | Specifies whether to enable manual major compaction. |
| global_major_freeze_residual_memory | The threshold of remaining memory for triggering a global freeze. When the available memory is less than this threshold, a global freeze is triggered. |
| minor_deferred_gc_time | The interval between the time when garbage collection starts for SSTables and the time when the major compaction ends. |
| zone_merge_concurrency | The number of zones supported in a major compaction. If this parameter is set to 0, the system determines the best level of concurrency based on the actual deployment status. |
| zone_merge_order | The order of zones in a rotating major compaction. If you do not specify this parameter, the system will determine its value. |
| zone_merge_timeout | The timeout period for the major compaction of a zone. |
| minor_freeze_times | 25200.minor_freeze_times.md |
| minor_merge_concurrency | The number of concurrent threads in a minor compaction. |
| minor_warm_up_duration_time | The preload time of the new MemTable generated after a minor compaction. |
| row_purge_thread_count | The maximum number of worker threads for a major compaction of rows in the memory. |
Arbitration service parameters
| Parameter | Description |
|---|---|
| ob_startup_mode | The startup mode of the OBServer node. This parameter can be modified only when the OBServer node is started for the first time. |
Tenant-level parameters
Security parameters
| Parameter | Description |
|---|---|
| external_kms_info | The key management information. |
| tde_method | The encryption method for a transparent tablespace. |
| audit_sys_operations | Specifies whether to track the operations of the SYS user. |
| audit_trail | Specifies whether to enable database audit. |
CPU parameters
| Parameter | Description |
|---|---|
| cpu_quota_concurrency | The maximum concurrency allowed for each CPU quota of a tenant. |
Read/Write and query parameters
| Parameter | Description |
|---|---|
| enable_monotonic_weak_read | Specifies whether to enable monotonic reads. |
| query_response_time_stats | Specifies whether to collect the statistics of the information_schema.QUERY_RESPONSE_TIME view. |
| query_response_time_flush | Specifies whether to refresh the information_schema.QUERY_RESPONSE_TIME view and re-read query_response_time_range_base. |
| query_response_time_range_base | The time interval at which the time parameters of the information_schema.QUERY_RESPONSE_TIME view are collected. |
Load balancing parameters
| Parameter | Description |
|---|---|
| balancer_idle_time | The interval for waking up the idle threads of backend tasks such as load balancing. |
| enable_rebalance | Specifies whether to enable automatic load balancing. |
| enable_transfer | Specifies whether to allow transfer within a tenant. This parameter is invalid when enable_rebalance is set to False. |
| partition_balance_schedule_interval | The scheduling interval of partition-level load balancing. |
Backup and restore parameters
| Parameter | Description |
|---|---|
| log_restore_concurrency | The concurrency of log restoration. |
| log_archive_concurrency | The concurrency of log archiving. |
| backup_data_file_size | The size of the backup data files. |
Background execution thread parameters
| Parameter | Description |
|---|---|
| compaction_low_thread_score | The weight of the CPU time slice occupied by the worker threads for low-priority compaction tasks. |
| compaction_high_thread_score | The weight of the CPU time slice occupied by the worker threads for high-priority compaction tasks. |
| compaction_mid_thread_score | The weight of the CPU time slice occupied by the worker threads for medium-priority compaction tasks. |
| ha_high_thread_score | The current number of high-availability high-priority worker threads. |
| ha_mid_thread_score | The current number of high-availability medium-priority worker threads. |
| ha_low_thread_score | The current number of high-availability low-priority worker threads. |
| ob_compaction_schedule_interval | The time interval for compaction scheduling. |
| compaction_dag_cnt_limit | The maximum number of directed acyclic graphs (DAGs) allowed in a compaction DAG queue. |
| compaction_schedule_tablet_batch_cnt | The maximum number of partitions that can be scheduled per batch during batch scheduling for compactions. |
| tenant_sql_login_thread_count | The number of logon threads of a MySQL tenant, that is, the number of mysql_queue threads. The default value 0 indicates that the value of the parameter is the same as that of unit_min_cpu. |
| tenant_sql_net_thread_count | The number of I/O threads of a MySQL tenant, that is, the number of sql_nio_server threads. The default value 0 indicates that the value of the parameter is the same as that of unit_min_cpu. |
I/O parameters
| Parameter | Description |
|---|---|
| io_category_config | The percentages of all types of I/O requests. |
Compatibility parameters
Note
The parameters described in the following table take effect only in MySQL mode.
| Parameter | Description |
|---|---|
| enable_sql_extension | Specifies whether to enable SQL extension for tenants. |
| compatible | Controls the compatibility of related features in a tenant. This parameter cannot be set. |
Routing parameters
| Parameter | Description |
|---|---|
| ob_proxy_readonly_transaction_routing_policy | Specifies whether OceanBase Database Proxy (ODP) routes a transaction based on read-only statements. |
Memory parameters
| Parameter | Description |
|---|---|
| rpc_memory_limit_percentage | The percentage of the maximum RPC memory in the tenant to the total tenant memory. |
| range_optimizer_max_mem_size | The maximum memory space available for the Query Range module. |
OBKV parameters
| Parameter | Description |
|---|---|
| kv_ttl_duty_duration | The time period during which scheduled daily time-to-live (TTL) tasks are to be triggered. |
| kv_ttl_history_recycle_interval | The retention period of historical TTL tasks. |
| enable_kv_ttl | Specifies whether to enable background TTL tasks. This parameter is applicable to periodic TTL tasks. User management commands are not limited by this parameter. |
| ttl_thread_score | The weight for using time slices by threads of TTL tasks. |
PL parameters
| Parameter | Description |
|---|---|
| plsql_code_type | The compilation mode of PL/SQL code. |
| plsql_debug | Specifies whether to compile code for debugging. |
| plsql_optimize_level | The compilation optimization level. |
| plsql_v2_compatibility | Specifies whether compatibility with Oracle 8 is supported. |
Other parameters
| Parameter | Description |
|---|---|
| enable_early_lock_release | Specifies whether to enable the early lock release (ELR) feature. |
| workarea_size_policy | Specifies whether the size of an SQL workarea is manually or automatically adjusted. |
| open_cursors | The maximum number of cursors that can be concurrently opened in a single session. |
| ob_ssl_invited_common_names | The list of identities of applications running under the current tenant. The identity of an application comes from the cn (common name) field of the subject of the client certificate in two-way SSL authentication. |
| ob_enable_batched_multi_statement | Specifies whether to enable group-based execution optimization for the batch processing feature. |
| job_queue_processes | The maximum number of concurrent tasks that can be run under each tenant. You can set this parameter to prevent tenant resources from being excessively occupied by tasks. |
| default_auto_increment_mode | The default auto-increment mode of auto-increment columns. |
| ob_query_switch_leader_retry_timeout | The maximum retry period for failed queries, in us. |
| default_enable_extended_rowid | default_enable_extended_rowid specifies whether to create the table in Extended ROWID mode. |
| dump_data_dictionary_to_log_interval | The interval of data dictionary persistence for the tenant. |
| enable_user_defined_rewrite_rules | Specifies whether to enable user-defined rules. |
Transaction and transaction log parameters
| Parameter | Description |
|---|---|
| log_disk_utilization_limit_threshold | The maximum usage of the tenant log disk. When the occupied space of the tenant log disk exceeds its total space multiplied by the specified value, log write is not allowed. |
| log_disk_utilization_threshold | The usage threshold of the tenant log disk. When the occupied space of the tenant log disk exceeds its total space multiplied by the specified value, log files are reused. |
| writing_throttling_maximum_duration | The time required for allocating the remaining memory of the MemStore after the write speed is limited. This parameter controls the write speed by controlling the memory allocation progress. |
| writing_throttling_trigger_percentage | The upper limit of the write speed. |
| standby_db_fetch_log_rpc_timeout | The timeout period of RPC requests sent by a standby cluster for pulling logs. If the specified timeout period is elapsed, the log transfer service of the standby cluster determines that the requested server in the primary cluster is unavailable and switches to another server. |
| log_disk_throttling_percentage | The percentage of unrecyclable disk space that triggers log write throttling. |
| log_transport_compress_all | Specifies whether to compress logs for transmission. |
| log_transport_compress_func | The algorithm for compressing logs for transmission. |
| clog_max_unconfirmed_log_count | The maximum number of unconfirmed logs allowed in the transaction module. |
| clog_persistence_compress_func | The algorithm for compressing transaction logs for storage. |
| enable_clog_persistence_compress | Specifies whether to compress transaction logs for storage. |
System log parameters
| Parameter | Description |
|---|---|
| log_disk_throttling_maximum_duration | The maximum available duration of the log disk after log throttling is triggered. |
| ls_gc_delay_time | The delay time before the log stream of a tenant is deleted. |
| standby_db_preferred_upstream_log_region | The preferred region for the standby tenant to synchronize upstream logs in a Physical Standby Database scenario. |
| archive_lag_target | The delay time of log archiving in a tenant. |
User logon parameters
Note
The parameters described in the following table take effect only in MySQL mode.
| Parameter | Description |
|---|---|
| connection_control_failed_connections_threshold | The threshold of failed logon attempts. |
| connection_control_min_connection_delay | The minimum lock period for an account whose number of failed logon attempts reaches the specified threshold. |
| connection_control_max_connection_delay | The maximum lock period for an account whose number of failed logon attempts reaches the specified threshold. |
Minor and major compaction parameters
| Parameter | Description |
|---|---|
| default_progressive_merge_num | The default number of progressive major compactions during table creation. |
| major_freeze_duty_time | The time to trigger a freeze and a major compaction every day. |
| major_compact_trigger | The number of minor compactions for triggering a global major compaction. |
| minor_compact_trigger | The threshold for triggering the next-level compaction in hierarchical minor compactions. |
| undo_retention | The time range in seconds of data versions to be retained by the system. This variable is used to control the collection of data of multiple versions in minor compactions. |
| merger_check_interval | The interval for scheduling the thread for checking the major compaction status. |
| freeze_trigger_percentage | The threshold of memory used by tenants for triggering a global freeze. |
| max_kept_major_version_number | The number of frozen data versions to be retained. |
| merge_stat_sampling_ratio | The sampling rate of data column statistics in a major compaction. |
| merge_thread_count | The number of worker threads for daily major compactions. |
| merger_completion_percentage | The percentage of compacted replicas at which the major compaction task is considered completed. |
| merger_switch_leader_duration_time | The interval for a batch leader switchover in a daily major compaction. |
| merger_warm_up_duration_time | The preload time of new baseline data in a major compaction. |
Arbitration service parameters
| Parameter | Description |
|---|---|
| arbitration_timeout | The timeout period for triggering an automatic downgrade. |
Unsupported parameters
| Parameter | Description |
|---|---|
| sql_work_area | The workarea memory of a tenant. |
| max_stale_time_for_weak_consistency | The maximum latency allowed in weak consistency reads. |