OceanBase Database Proxy

V4.3.3

What is ODP?
Installation and deployment
- Overview
- Deploy ODP by using obd
- Deploy ODP by using OCP
- Deploy ODP by using the CLI
- Deployment modes
Basic operations
Configuration parameter
- View and modify parameters
- Parameter summary
- Global parameters
  - automatic_match_work_thread
  - block_thread_num
  - cache_cleaner_clean_interval
  - check_tenant_locality_change
  - client_max_connections
  - client_max_memory_size
  - client_session_id_version
  - client_sock_option_flag_out
  - client_tcp_keepcnt
  - client_tcp_keepidle
  - client_tcp_keepintvl
  - client_tcp_user_timeout
  - cluster_count_high_water_mark
  - cluster_expire_time
  - config_server_refresh_interval
  - congestion_fail_window
  - congestion_failure_threshold
  - congestion_retry_interval
  - connection_diagnosis_option
  - connect_observer_max_retries
  - current_local_config_version
  - default_buffer_water_mark
  - default_inactivity_timeout
  - delay_exit_time
  - delay_update_entry_interval
  - detect_server_timeout
  - digest_sql_length
  - enable_abort_conn_info
  - enable_async_log
  - enable_async_pull_location_cache
  - enable_bad_route_reject
  - enable_binlog_service
  - enable_cached_server
  - enable_causal_order_read
  - enable_client_connection_lru_disconnect
  - enable_client_ip_checkout
  - enable_cluster_checkout
  - enable_compression_protocol
  - enable_congestion
  - enable_connection_diagnosis
  - enable_cpu_isolate
  - enable_cpu_topology
  - enable_extra_prometheus_metric
  - enable_flow_control
  - enable_full_link_trace
  - enable_full_username
  - enable_get_rslist_remote
  - enable_global_ps_cache
  - enable_index_route
  - enable_monitor_stat
  - enable_ob_protocol_v2
  - enable_ob_protocol_v2_with_client
  - enable_obproxy_rpc_service
  - enable_partition_table_route
  - enable_performance_mode
  - enable_pl_route
  - enable_primary_zone
  - enable_prometheus
  - enable_proxy_scramble
  - enable_qa_mode
  - enable_qos
  - enable_report_session_stats
  - enable_reroute
  - enable_sequence_prefetch
  - enable_sharding
  - enable_single_leader_node_routing
  - enable_standby
  - enable_stat
  - enable_strict_kernel_release
  - enable_strict_stat_time
  - enable_sync_all_stats
  - enable_syslog_file_compress
  - enable_syslog_wf
  - enable_trace
  - enable_trace_stats
  - enable_trans_detail_stats
  - enable_transaction_internal_routing
  - enable_xa_route
  - fetch_proxy_bin_random_time
  - fetch_proxy_bin_timeout
  - flow_consumer_reenable_threshold
  - flow_event_queue_threshold
  - flow_high_water_mark
  - flow_low_water_mark
  - grpc_client_num
  - grpc_thread_num
  - hot_upgrade_exit_timeout
  - hot_upgrade_failure_retries
  - hot_upgrade_rollback_timeout
  - idc_list_refresh_interval
  - ignore_local_config
  - internal_cmd_mem_limited
  - ip_listen_mode
  - ldg_info_refresh_interval
  - listen_port
  - local_bound_ip
  - local_bound_ipv6_ip
  - log_cleanup_interval
  - log_dir_size_threshold
  - log_file_percentage
  - long_async_task_timeout
  - max_log_file_size
  - max_syslog_file_count
  - max_syslog_file_time
  - mem_leak_check_class_name
  - mem_leak_check_mod_name
  - metadb_server_state_refresh_interval
  - min_congested_connect_timeout
  - min_keep_congestion_interval
  - monitor_cost_ms_unit
  - monitor_item_limit
  - monitor_item_max_idle_period
  - monitor_log_level
  - monitor_stat_dump_interval
  - monitor_stat_high_threshold
  - monitor_stat_low_threshold
  - monitor_stat_middle_threshold
  - need_convert_vip_to_tname
  - net_accept_threads
  - net_config_poll_timeout
  - normal_pl_update_threshold
  - obproxy_config_server_url
  - obproxy_sys_password
  - partition_location_expire_relative_time
  - prometheus_cost_ms_unit
  - prometheus_listen_port
  - prometheus_sync_interval
  - protocol_diagnosis_level
  - proxy_hot_upgrade_check_interval
  - proxy_id
  - proxy_info_check_interval
  - proxy_local_cmd
  - proxy_mem_limited
  - qa_mode_mock_public_cloud_slb_addr
  - qos_stat_clean_interval
  - qos_stat_item_limit
  - refresh_idc_list
  - refresh_json_config
  - refresh_rslist
  - request_buffer_length
  - rootservice_list
  - routing_cache_mem_limited
  - rpc_async_task_thread_num
  - rpc_enable_congestion
  - rpc_enable_direct_expire_route_entry
  - rpc_enable_global_index
  - rpc_enable_force_srv_black_list
  - rpc_enable_parallel_handler
  - rpc_enable_reroute
  - rpc_enable_retry_request_info_log
  - rpc_force_srv_black_list
  - rpc_listen_port
  - rpc_max_request_batch_size
  - rpc_max_response_batch_size
  - rpc_net_timeout_base
  - rpc_max_server_table_entry_num
  - rpc_redis_operation_timeout
  - rpc_redis_default_database_name
  - rpc_period_task_interval
  - rpc_redis_default_user_name
  - rpc_request_timeout
  - rpc_server_entry_expire_time
  - rpc_request_timeout_delta
  - rpc_server_net_invalid_time_us
  - rpc_server_net_handler_expire_time
  - rpc_server_net_max_pending_request
  - rpc_srv_session_pool_inactive_timeout
  - rpc_service_mode
  - rpc_sub_request_isolation_mode
  - rpc_support_key_partition_shard_request
  - rpc_sub_request_weight
  - sequence_entry_expire_time
  - sequence_fail_retry_count
  - sequence_prefetch_threshold
  - server_detect_fail_threshold
  - server_detect_mode
  - server_detect_refresh_interval
  - server_routing_mode
  - server_state_refresh_interval
  - server_tcp_init_cwnd
  - server_tcp_keepcnt
  - server_tcp_keepidle
  - server_tcp_keepintvl
  - server_tcp_user_timeout
  - shard_scan_thread_num
  - short_async_task_timeout
  - skip_proxy_sys_private_check
  - skip_proxyro_check
  - slow_proxy_process_time_threshold
  - slow_transaction_time_threshold
  - sock_option_flag_out
  - sock_packet_mark_out
  - sock_packet_tos_out
  - sock_recv_buffer_size_out
  - sock_send_buffer_size_out
  - sql_table_cache_expire_relative_time
  - sql_table_cache_mem_limited
  - sqlaudit_mem_limited
  - stack_size
  - stat_dump_interval
  - stat_table_sync_interval
  - syslog_io_bandwidth_limit
  - syslog_level
  - task_thread_num
  - tenant_location_valid_time
  - tunnel_request_size_threshold
  - username_separator
  - work_thread_num
  - xflush_log_level
- Multi-level parameters
  - binlog_service_ip
  - compression_algorithm
  - enable_check_cluster_name
  - enable_client_ssl
  - enable_cloud_full_username
  - enable_read_write_split
  - enable_rpc_throttle
  - enable_server_ssl
  - enable_standby_read_write_split
  - enable_transaction_split
  - enable_weak_reroute
  - mysql_version
  - ob_max_read_stale_time
  - obproxy_force_parallel_query_dop
  - obproxy_read_consistency
  - obproxy_read_only
  - observer_query_timeout_delta
  - observer_sys_password
  - observer_sys_password1
  - proxy_idc_name
  - proxy_primary_zone_name
  - proxy_route_policy
  - proxy_tenant_name
  - query_digest_time_threshold
  - read_stale_retry_interval
  - rootservice_cluster_name
  - route_diagnosis_level
  - rpc_request_throttle_waiting_time
  - rpc_throttle_limit_qps_qa
  - route_target_replica_type
  - rpc_throttle_trigger_percentage
  - slow_query_time_threshold
  - sql_firewall_config
  - ssl_attributes
  - target_db_server
  - weakread_weight_zone
Connection management
- Principles
- Session status synchronization
- Configure a globally unique client session ID
- Client session
- Server session
- Network connection
Data routing
- Factors affecting data routing
- ODP routing
- Intra-tenant routing
  - Overview
  - IP address-based routing
  - Partitioned table-based routing for strong-consistency reads
  - Global index table-based routing for strong-consistency reads
  - Replicated table-based routing for strong-consistency reads
  - Primary zone-based routing for strong-consistency reads
  - Strategy-based routing
  - Distributed transaction routing
  - Rerouting
  - Forcible routing
  - Weight-based load-balanced routing
- Automatic routing to the primary/standby tenants
- Read/Write separation
- Follower latency threshold
- Function partition key routing
  - Overview
  - String functions
  - Numeric calculation functions
  - Date calculation functions
  - FAQ
- Character set-based routing
- Partitioning key types supported for routing by ODP
Logs
- Overview
- obproxy_diagnosis.log
- obproxy_digest.log
- obproxy_error.log
- obproxy_slow.log
- obproxy_stat.log
- obproxy.log
Commands
- Overview
- Dedicated ODP commands
  - ALTER
  - KILL
  - ping
  - SHOW
    - SHOW
    - SHOW PROXYPS
- Compatible MySQL commands
  - BINLOG
  - KILL
  - SHOW PROCESSLIST
  - SHOW RELAYLOG EVENTS
  - SHOW SLAVE HOSTS
High availability mechanism
- Overview
- High availability of ODP services
- High availability of OceanBase Database
- High availability testing
OBKV
- RPC service port
- Throttling
- OBKV-Redis
Security and protocols
Operation and maintenance
- Troubleshooting logic
- Performance analysis
- Show Trace
- Routing diagnostics
  - Overview
  - Obtain diagnostic information
  - Diagnostic point troubleshooting
    - Overview
    - SQL_PARSE
    - ROUTE_INFO
    - LOCATION_CACHE_LOOKUP
    - ROUTINE_ENTRY_LOOKUP_DONE
    - FETCH_TABLE_RELATED_DATA
    - TABLE_ENTRY_LOOKUP_DONE
    - EXPR_PARSE
    - CALC_ROWID
    - RESOLVE_TOKEN
    - RESOLVE_EXPR
    - CALC_PARTITION_ID
    - PARTITION_ID_CALC_DONE
    - PARTITION_ENTRY_LOOKUP_DONE
    - ROUTE_POLICY
    - CONGESTION_CONTROL
    - RETRY
    - HANDLE_RESPONSE
  - Examples
- Memory leak diagnostics
- Connection diagnostics
- Prometheus monitoring
- SQL firewall
Release Notes
- Versioning rules
- Enterprise Edition
  - V4.3
    - ODP Enterprise Edition V4.3.3
    - ODP Enterprise Edition V4.3.2
    - ODP Enterprise Edition V4.3.1
    - ODP Enterprise Edition V4.3.0
  - V4.2
    - ODP Enterprise Edition V4.2.3
    - ODP Enterprise Edition V4.2.2
    - ODP Enterprise Edition V4.2.1
  - V4.1
    - ODP Enterprise Edition V4.1.0
  - V4.0
    - ODP Enterprise Edition V4.0.0
  - V3.2
    - ODP Enterprise Edition V3.2.11
    - ODP Enterprise Edition V3.2.3.5
- Community Edition
  - V4.3
    - ODP Community Edition V4.3.3
    - ODP Community Edition V4.3.2
    - ODP Community Edition V4.3.1
  - V4.2
    - ODP Community Edition V4.2.3
    - ODP Community Edition V4.2.1
    - ODP Community Edition V4.2.0
  - V4.1
    - ODP Community Edition V4.1.0
  - V4.0
    - ODP Community Edition V4.0.0

Download PDF

OceanBase, A Highly Scalable Database for Transactional, Analytical, and AI Workloads.

Company

About OceanBase Contact Us Partner

Product

OceanBase Cloud OceanBase Enterprise Quick Start Download Pricing

Resources

Docs Blog White Paper Trust Center

Document Feedback

sequence_prefetch_threshold

Last Updated：2025-03-21 09:20:00 Updated

sequence_prefetch_threshold specifies the maximum cost for triggering prefetch. A prefetch is triggered when the cost reaches the specified threshold.

Attribute	Description
Parameter type	Integer
Default value	7000
Value range	[0, 10000]
Effective only after ODP restart	No

Previous topic

sequence_fail_retry_count

Last

Next topic

server_detect_fail_threshold