{ "system_type": "TiDB", "version": "v6.1.0", "knobs": [ { "name": "tidb_distsql_scan_concurrency", "var_type": "INTEGER", "unit": "other", "category": "system_variables", "description": "Set the concurrency of the scan operation.", "scope": "global", "min_val": "1", "max_val": "256", "default": "15", "enum_vals": null, "tunable": true, "resource": "CPU" }, { "name": "tidb_executor_concurrency", "var_type": "INTEGER", "unit": "other", "category": "system_variables", "description": "Set the concurrency of some SQL operators, such as 'index lookup', 'hash join', 'hash aggregation' etc.", "scope": "global", "min_val": "1", "max_val": "256", "default": "5", "enum_vals": null, "tunable": true, "resource": "CPU" }, { "name": "tidb_guarantee_linearizability", "var_type": "ENUM", "unit": "other", "category": "system_variables", "description": "This variable controls the way commit TS is calculated for async commit.", "scope": "global", "min_val": null, "max_val": null, "default": "ON", "enum_vals": "OFF,ON", "tunable": true, "resource": "Other" }, { "name": "tidb_enable_clustered_index", "var_type": "ENUM", "unit": "other", "category": "system_variables", "description": "This variable is used to control whether to create the primary key as a clustered index by default.", "scope": "global", "min_val": null, "max_val": null, "default": "INT_ONLY", "enum_vals": "OFF,ON,INT_ONLY", "tunable": true, "resource": "Other" }, { "name": "tidb_index_serial_scan_concurrency", "var_type": "INTEGER", "unit": "other", "category": "system_variables", "description": "This variable is used to set the concurrency of the serial scan operation.", "scope": "global", "min_val": "1", "max_val": "256", "default": "1", "enum_vals": null, "tunable": true, "resource": "CPU" }, { "name": "tidb_build_stats_concurrency", "var_type": "INTEGER", "unit": "other", "category": "system_variables", "description": "This variable is used to set the concurrency of executing the ANALYZE statement.", "scope": "global", "min_val": "1", "max_val": "256", "default": "4", "enum_vals": null, "tunable": true, "resource": "CPU" }, { "name": "tidb_enable_prepared_plan_cache", "var_type": "ENUM", "unit": "other", "category": "system_variables", "description": "Determines whether to enable 'Prepared Plan Cache'.", "scope": "global", "min_val": null, "max_val": null, "default": "ON", "enum_vals": "OFF,ON", "tunable": true, "resource": "Memory" }, { "name": "tidb_prepared_plan_cache_size", "var_type": "INTEGER", "unit": "other", "category": "system_variables", "description": "The maximum number of plans that can be cached in a session.", "scope": "global", "min_val": "1", "max_val": "100000", "default": "100", "enum_vals": null, "tunable": true, "resource": "Memory" }, { "name": "tidb_committer_concurrency", "var_type": "INTEGER", "unit": "other", "category": "system_variables", "description": "The number of goroutines for requests related to executing commit in the commit phase of the single transaction.", "scope": "global", "min_val": "1", "max_val": "10000", "default": "128", "enum_vals": null, "tunable": true, "resource": "CPU" }, { "name": "tidb.token-limit", "var_type": "INTEGER", "unit": "other", "category": "tidb_variables", "description": "The limit of concurrent executed sessions.", "scope": "global", "min_val": "100", "max_val": "5000", "default": "1000", "enum_vals": null, "tunable": true, "resource": "Other" }, { "name": "tidb.performance.gogc", "var_type": "INTEGER", "unit": "other", "category": "tidb_variables", "description": "The Go GC trigger factor", "scope": "global", "min_val": "100", "max_val": "400", "default": "100", "enum_vals": null, "tunable": true, "resource": "Memory" }, { "name": "tidb.performance.distinct-agg-push-down", "var_type": "ENUM", "unit": "other", "category": "tidb_variables", "description": "Whether support pushing down aggregation with distinct to cop task.", "scope": "global", "min_val": null, "max_val": null, "default": "false", "enum_vals": "false,true", "tunable": true, "resource": "Other" }, { "name": "tidb.tikv-client.grpc-connection-count", "var_type": "INTEGER", "unit": "other", "category": "tidb_variables", "description": "Max gRPC connections that will be established with each tikv-server.", "scope": "global", "min_val": "2", "max_val": "20", "default": "4", "enum_vals": null, "tunable": true, "resource": "Other" }, { "name": "tidb.tikv-client.copr-cache.capacity-mb", "var_type": "REAL", "unit": "other", "category": "tidb_variables", "description": "The capacity in MB of the cache.", "scope": "global", "min_val": "0.0", "max_val": "3000.0", "default": "1000.0", "enum_vals": null, "tunable": true, "resource": "Memory" }, { "name": "tikv.raft-engine.enable", "var_type": "ENUM", "unit": "other", "category": "tikv_variables", "description": "Determines whether to use Raft Engine to store raft logs.", "scope": "global", "min_val": null, "max_val": null, "default": "true", "enum_vals": "false,true", "tunable": true, "resource": "Other" }, { "name": "tikv.raftstore.store-io-pool-size", "var_type": "INTEGER", "unit": "other", "category": "tikv_variables", "description": "Use how many threads to handle raft io tasks.", "scope": "global", "min_val": "0", "max_val": "5", "default": "0", "enum_vals": null, "tunable": true, "resource": "CPU" }, { "name": "tikv.raftstore.store-pool-size", "var_type": "INTEGER", "unit": "other", "category": "tikv_variables", "description": "Use how many threads to handle raft messages.", "scope": "global", "min_val": "1", "max_val": "16", "default": "2", "enum_vals": null, "tunable": true, "resource": "CPU" }, { "name": "tikv.raftstore.apply-pool-size", "var_type": "INTEGER", "unit": "other", "category": "tikv_variables", "description": "Use how many threads to handle log apply.", "scope": "global", "min_val": "2", "max_val": "16", "default": "2", "enum_vals": null, "tunable": true, "resource": "CPU" }, { "name": "tikv.raftstore.apply-max-batch-size", "var_type": "INTEGER", "unit": "other", "category": "tikv_variables", "description": "Raft state machines process data write requests in batches by the BatchSystem.", "scope": "global", "min_val": "1", "max_val": "10240", "default": "256", "enum_vals": null, "tunable": true, "resource": "Other" }, { "name": "tikv.raftstore.local-read-batch-size", "var_type": "INTEGER", "unit": "other", "category": "tikv_variables", "description": "The maximum number of read requests processed in one batch.", "scope": "global", "min_val": "1", "max_val": "4096", "default": "1024", "enum_vals": null, "tunable": true, "resource": "Other" }, { "name": "tikv.raftstore.store-max-batch-size", "var_type": "INTEGER", "unit": "other", "category": "tikv_variables", "description": "Raft state machines process requests for flushing logs into the disk in batches by the BatchSystem.", "scope": "global", "min_val": "1", "max_val": "10240", "default": "256", "enum_vals": null, "tunable": true, "resource": "Other" }, { "name": "tikv.storage.scheduler-worker-pool-size", "var_type": "INTEGER", "unit": "other", "category": "tikv_variables", "description": "The number of threads in the Scheduler thread pool.", "scope": "global", "min_val": "2", "max_val": "8", "default": "4", "enum_vals": null, "tunable": true, "resource": "CPU" }, { "name": "tikv.raftdb.max-background-jobs", "var_type": "INTEGER", "unit": "other", "category": "tikv_variables", "description": "The number of background threads in RocksDB.", "scope": "global", "min_val": "2", "max_val": "16", "default": "4", "enum_vals": null, "tunable": true, "resource": "CPU" }, { "name": "tikv.raftdb.max-sub-compactions", "var_type": "INTEGER", "unit": "other", "category": "tikv_variables", "description": "The number of concurrent sub-compaction operations performed in RocksDB.", "scope": "global", "min_val": "1", "max_val": "16", "default": "2", "enum_vals": null, "tunable": true, "resource": "CPU" }, { "name": "tikv.readpool.unified.min-thread-count", "var_type": "INTEGER", "unit": "other", "category": "tikv_variables", "description": "The minimal working thread count of the unified read pool.", "scope": "global", "min_val": "1", "max_val": "4", "default": "1", "enum_vals": null, "tunable": true, "resource": "CPU" }, { "name": "tikv.readpool.unified.max-thread-count", "var_type": "INTEGER", "unit": "other", "category": "tikv_variables", "description": "The maximum working thread count of the unified read pool or the UnifyReadPool thread pool.", "scope": "global", "min_val": "4", "max_val": "8", "default": "4", "enum_vals": null, "tunable": true, "resource": "CPU" }, { "name": "tikv.rocksdb.max-background-jobs", "var_type": "INTEGER", "unit": "other", "category": "tikv_variables", "description": "The number of background threads in RocksDB.", "scope": "global", "min_val": "2", "max_val": "32", "default": "7", "enum_vals": null, "tunable": true, "resource": "CPU" }, { "name": "tikv.rocksdb.max-sub-compactions", "var_type": "INTEGER", "unit": "other", "category": "tikv_variables", "description": "The number of sub-compaction operations performed concurrently in RocksDB.", "scope": "global", "min_val": "1", "max_val": "16", "default": "3", "enum_vals": null, "tunable": true, "resource": "CPU" }, { "name": "tikv.server.grpc-concurrency", "var_type": "INTEGER", "unit": "other", "category": "tikv_variables", "description": "The number of gRPC worker threads.", "scope": "global", "min_val": "1", "max_val": "16", "default": "5", "enum_vals": null, "tunable": true, "resource": "CPU" }, { "name": "tikv.server.grpc-raft-conn-num", "var_type": "INTEGER", "unit": "other", "category": "tikv_variables", "description": "The maximum number of links among TiKV nodes for Raft communication.", "scope": "global", "min_val": "1", "max_val": "16", "default": "1", "enum_vals": null, "tunable": true, "resource": "CPU" }, { "name": "tikv.storage.block-cache.shared", "var_type": "ENUM", "unit": "other", "category": "tikv_variables", "description": "Enables or disables the sharing of block cache.", "scope": "global", "min_val": null, "max_val": null, "default": "true", "enum_vals": "false,true", "tunable": true, "resource": "Memory" }, { "name": "tikv.storage.block-cache.capacity", "var_type": "INTEGER", "unit": "bytes", "category": "tikv_variables", "description": "Size of the shared block cache", "scope": "global", "min_val": "0", "max_val": "68719476736", "default": "0", "enum_vals": null, "tunable": true, "resource": "Memory" } ], "metrics": [ { "name":"tidb.tidb_qps", "var_type": "REAL", "unit": "other", "description": "The throughput of the tidb server", "metric_type": "STATISTICS", "scope": "global" }, { "name":"tidb.tidb_query_duration", "var_type": "REAL", "unit": "seconds", "description": "The query duration of the tidb server", "metric_type": "STATISTICS", "scope": "global" } ] }