- About TiDB
- Quick Start
- Deploy
- Software and Hardware Requirements
- Environment Configuration Checklist
- Topology Patterns
- Install and Start
- Verify Cluster Status
- Benchmarks Methods
- Migrate
- Maintain
- Monitor and Alert
- Troubleshoot
- TiDB Troubleshooting Map
- Identify Slow Queries
- Analyze Slow Queries
- SQL Diagnostics
- Identify Expensive Queries
- Statement Summary Tables
- Troubleshoot Hotspot Issues
- Troubleshoot Increased Read and Write Latency
- Troubleshoot Cluster Setup
- Troubleshoot High Disk I/O Usage
- Troubleshoot Lock Conflicts
- Troubleshoot TiFlash
- Troubleshoot Write Conflicts in Optimistic Transactions
- Performance Tuning
- System Tuning
- Software Tuning
- SQL Tuning
- Overview
- Understanding the Query Execution Plan
- SQL Optimization Process
- Overview
- Logic Optimization
- Physical Optimization
- Prepare Execution Plan Cache
- Control Execution Plans
- Tutorials
- TiDB Tools
- Overview
- Use Cases
- Download
- TiUP
- TiDB Operator
- Backup & Restore (BR)
- TiDB Binlog
- TiDB Lightning
- TiDB Data Migration
- TiCDC
- Dumpling
- sync-diff-inspector
- Loader
- Mydumper
- Syncer
- TiSpark
- Reference
- Cluster Architecture
- Key Monitoring Metrics
- Secure
- Privileges
- SQL
- SQL Language Structure and Syntax
- SQL Statements
ADD COLUMN
ADD INDEX
ADMIN
ADMIN CANCEL DDL
ADMIN CHECKSUM TABLE
ADMIN CHECK [TABLE|INDEX]
ADMIN SHOW DDL [JOBS|QUERIES]
ALTER DATABASE
ALTER INSTANCE
ALTER TABLE
ALTER USER
ANALYZE TABLE
BACKUP
BEGIN
CHANGE COLUMN
COMMIT
CHANGE DRAINER
CHANGE PUMP
CREATE [GLOBAL|SESSION] BINDING
CREATE DATABASE
CREATE INDEX
CREATE ROLE
CREATE SEQUENCE
CREATE TABLE LIKE
CREATE TABLE
CREATE USER
CREATE VIEW
DEALLOCATE
DELETE
DESC
DESCRIBE
DO
DROP [GLOBAL|SESSION] BINDING
DROP COLUMN
DROP DATABASE
DROP INDEX
DROP ROLE
DROP SEQUENCE
DROP STATS
DROP TABLE
DROP USER
DROP VIEW
EXECUTE
EXPLAIN ANALYZE
EXPLAIN
FLASHBACK TABLE
FLUSH PRIVILEGES
FLUSH STATUS
FLUSH TABLES
GRANT <privileges>
GRANT <role>
INSERT
KILL [TIDB]
LOAD DATA
LOAD STATS
MODIFY COLUMN
PREPARE
RECOVER TABLE
RENAME INDEX
RENAME TABLE
REPLACE
RESTORE
REVOKE <privileges>
REVOKE <role>
ROLLBACK
SELECT
SET DEFAULT ROLE
SET [NAMES|CHARACTER SET]
SET PASSWORD
SET ROLE
SET TRANSACTION
SET [GLOBAL|SESSION] <variable>
SHOW ANALYZE STATUS
SHOW [BACKUPS|RESTORES]
SHOW [GLOBAL|SESSION] BINDINGS
SHOW BUILTINS
SHOW CHARACTER SET
SHOW COLLATION
SHOW [FULL] COLUMNS FROM
SHOW CONFIG
SHOW CREATE SEQUENCE
SHOW CREATE TABLE
SHOW CREATE USER
SHOW DATABASES
SHOW DRAINER STATUS
SHOW ENGINES
SHOW ERRORS
SHOW [FULL] FIELDS FROM
SHOW GRANTS
SHOW INDEX [FROM|IN]
SHOW INDEXES [FROM|IN]
SHOW KEYS [FROM|IN]
SHOW MASTER STATUS
SHOW PLUGINS
SHOW PRIVILEGES
SHOW [FULL] PROCESSSLIST
SHOW PROFILES
SHOW PUMP STATUS
SHOW SCHEMAS
SHOW STATS_HEALTHY
SHOW STATS_HISTOGRAMS
SHOW STATS_META
SHOW STATUS
SHOW TABLE NEXT_ROW_ID
SHOW TABLE REGIONS
SHOW TABLE STATUS
SHOW [FULL] TABLES
SHOW [GLOBAL|SESSION] VARIABLES
SHOW WARNINGS
SHUTDOWN
SPLIT REGION
START TRANSACTION
TRACE
TRUNCATE
UPDATE
USE
- Data Types
- Functions and Operators
- Overview
- Type Conversion in Expression Evaluation
- Operators
- Control Flow Functions
- String Functions
- Numeric Functions and Operators
- Date and Time Functions
- Bit Functions and Operators
- Cast Functions and Operators
- Encryption and Compression Functions
- Information Functions
- JSON Functions
- Aggregate (GROUP BY) Functions
- Window Functions
- Miscellaneous Functions
- Precision Math
- List of Expressions for Pushdown
- Constraints
- Generated Columns
- SQL Mode
- Transactions
- Garbage Collection (GC)
- Views
- Partitioning
- Character Set and Collation
- System Tables
mysql
- INFORMATION_SCHEMA
- Overview
ANALYZE_STATUS
CHARACTER_SETS
CLUSTER_CONFIG
CLUSTER_HARDWARE
CLUSTER_INFO
CLUSTER_LOAD
CLUSTER_LOG
CLUSTER_SYSTEMINFO
COLLATIONS
COLLATION_CHARACTER_SET_APPLICABILITY
COLUMNS
DDL_JOBS
ENGINES
INSPECTION_RESULT
INSPECTION_RULES
INSPECTION_SUMMARY
KEY_COLUMN_USAGE
METRICS_SUMMARY
METRICS_TABLES
PARTITIONS
PROCESSLIST
SCHEMATA
SEQUENCES
SESSION_VARIABLES
SLOW_QUERY
STATISTICS
TABLES
TABLE_CONSTRAINTS
TABLE_STORAGE_STATS
TIDB_HOT_REGIONS
TIDB_INDEXES
TIDB_SERVERS_INFO
TIFLASH_REPLICA
TIKV_REGION_PEERS
TIKV_REGION_STATUS
TIKV_STORE_STATUS
USER_PRIVILEGES
VIEWS
METRICS_SCHEMA
- UI
- TiDB Dashboard
- Overview
- Maintain
- Access
- Overview Page
- Cluster Info Page
- Key Visualizer Page
- Metrics Relation Graph
- SQL Statements Analysis
- Slow Queries Page
- Cluster Diagnostics
- Search Logs Page
- Profile Instances Page
- Session Management and Configuration
- FAQ
- CLI
- Command Line Flags
- Configuration File Parameters
- System Variables
- Storage Engines
- Telemetry
- Errors Codes
- Table Filter
- Schedule Replicas by Topology Labels
- FAQs
- Release Notes
- All Releases
- v4.0
- v3.1
- v3.0
- v2.1
- v2.0
- v1.0
- Glossary
Daily Check
As a distributed database, TiDB is more complicated than the stand-alone database in terms of the mechanism, and monitoring items. To help operate and maintain TiDB in a more convenient way, this document introduces some key performance indicators.
Key indicators of TiDB Dashboard
Starting from v4.0, TiDB provides a new operation and maintenance management tool, TiDB Dashboard. This tool is integrated into the PD component. You can access TiDB Dashboard at the default address http://${pd-ip}:${pd_port}/dashboard
.
TiDB Dashboard simplifies the operation and maintenance of the TiDB database. You can view the running status of the entire TiDB cluster through one interface. The following are descriptions of some performance indicators.
Instance panel
- Status: This indicator is used to check whether the status is normal. For an online node, this can be ignored.
- Up Time: The key indicator. If you find that the
Up Time
is changed, you need to locate the reason why the component is restarted. - Version, Deployment Directory, Git Hash: These indicators need to be checked to avoid inconsistent or even incorrect version/deployment directory.
Host panel
You can view the usage of CPU, memory, and disk. When the usage of any resource exceeds 80%, it is recommended to scale out the capacity accordingly.
SQL analysis panel
You can locate the slow SQL statement executed in the cluster. Then you can optimize the specific SQL statement.
Region panel
miss-peer-region-count
: The number of Regions without enough replicas. This value is not always greater than0
.extra-peer-region-count
: The number of Regions with extra replicas. These Regions are generated during the scheduling process.empty-region-count
: The number of empty Regions, generated by executing theTRUNCATE TABLE
/DROP TABLE
statement. If this number is large, you can consider enablingRegion Merge
to merge Regions across tables.pending-peer-region-count
: The number of Regions with outdated Raft logs. It is normal that a few pending peers are generated in the scheduling process. However, it is not normal if this value is large for a period of time.down-peer-region-count
: The number of Regions with an unresponsive peer reported by the Raft leader.offline-peer-region-count
: The number of Regions during the offline process.
Generally, it is normal that these values are not 0
. However, it is not normal that they are not 0
for quite a long time.
KV Request Duration
The KV request duration 99 in TiKV. If you find nodes with a long duration, check whether there are hot spots, or whether there are nodes with poor performance.
PD TSO Wait Duration
The time it takes for TiDB to obtain TSO from PD. The following are reasons for the long wait duration:
- High network latency from TiDB to PD. You can manually execute the ping command to test the network latency.
- High load for the TiDB server.
- High load for the PD server.
Overview panel
You can view the load, memory available, network traffic, and I/O utilities. When a bottleneck is found, it is recommended to scale out the capacity, or to optimize the cluster topology, SQL, cluster parameters, etc.
Exceptions
You can view the errors triggered by the execution of SQL statements on each TiDB instance. These include syntax error, primary key conflicts, etc.
GC status
You can check whether the GC (Garbage Collection) status is normal by viewing the time when the last GC happens. If the GC is abnormal, it might lead to excessive historical data, thereby decreasing the access efficiency.