- Docs Home
- About TiDB
- Quick Start
- Develop
- Overview
- Quick Start
- Build a TiDB Cluster in TiDB Cloud (Developer Tier)
- CRUD SQL in TiDB
- Build a Simple CRUD App with TiDB
- Example Applications
- Connect to TiDB
- Design Database Schema
- Write Data
- Read Data
- Transaction
- Optimize
- Troubleshoot
- Reference
- Cloud Native Development Environment
- Third-party Support
- Deploy
- Software and Hardware Requirements
- Environment Configuration Checklist
- Plan Cluster Topology
- Install and Start
- Verify Cluster Status
- Test Cluster Performance
- Migrate
- Overview
- Migration Tools
- Migration Scenarios
- Migrate from Aurora
- Migrate MySQL of Small Datasets
- Migrate MySQL of Large Datasets
- Migrate and Merge MySQL Shards of Small Datasets
- Migrate and Merge MySQL Shards of Large Datasets
- Migrate from CSV Files
- Migrate from SQL Files
- Migrate from One TiDB Cluster to Another TiDB Cluster
- Migrate from TiDB to MySQL-compatible Databases
- Advanced Migration
- Integrate
- Overview
- Integration Scenarios
- Maintain
- Monitor and Alert
- Troubleshoot
- TiDB Troubleshooting Map
- Identify Slow Queries
- Analyze Slow Queries
- SQL Diagnostics
- Identify Expensive Queries Using Top SQL
- Identify Expensive Queries Using Logs
- Statement Summary Tables
- Troubleshoot Hotspot Issues
- Troubleshoot Increased Read and Write Latency
- Save and Restore the On-Site Information of a Cluster
- Troubleshoot Cluster Setup
- Troubleshoot High Disk I/O Usage
- Troubleshoot Lock Conflicts
- Troubleshoot TiFlash
- Troubleshoot Write Conflicts in Optimistic Transactions
- Troubleshoot Inconsistency Between Data and Indexes
- Performance Tuning
- Tuning Guide
- Configuration 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
- Documentation Map
- Overview
- Terminology and Concepts
- Manage TiUP Components
- FAQ
- Troubleshooting Guide
- Command Reference
- Overview
- TiUP Commands
- TiUP Cluster Commands
- Overview
- tiup cluster audit
- tiup cluster check
- tiup cluster clean
- tiup cluster deploy
- tiup cluster destroy
- tiup cluster disable
- tiup cluster display
- tiup cluster edit-config
- tiup cluster enable
- tiup cluster help
- tiup cluster import
- tiup cluster list
- tiup cluster patch
- tiup cluster prune
- tiup cluster reload
- tiup cluster rename
- tiup cluster replay
- tiup cluster restart
- tiup cluster scale-in
- tiup cluster scale-out
- tiup cluster start
- tiup cluster stop
- tiup cluster template
- tiup cluster upgrade
- TiUP DM Commands
- Overview
- tiup dm audit
- tiup dm deploy
- tiup dm destroy
- tiup dm disable
- tiup dm display
- tiup dm edit-config
- tiup dm enable
- tiup dm help
- tiup dm import
- tiup dm list
- tiup dm patch
- tiup dm prune
- tiup dm reload
- tiup dm replay
- tiup dm restart
- tiup dm scale-in
- tiup dm scale-out
- tiup dm start
- tiup dm stop
- tiup dm template
- tiup dm upgrade
- TiDB Cluster Topology Reference
- DM Cluster Topology Reference
- Mirror Reference Guide
- TiUP Components
- PingCAP Clinic Diagnostic Service
- TiDB Operator
- Dumpling
- TiDB Lightning
- TiDB Data Migration
- About TiDB Data Migration
- Architecture
- Quick Start
- Deploy a DM cluster
- Tutorials
- Advanced Tutorials
- Maintain
- Cluster Upgrade
- Tools
- Performance Tuning
- Manage Data Sources
- Manage Tasks
- Export and Import Data Sources and Task Configurations of Clusters
- Handle Alerts
- Daily Check
- Reference
- Architecture
- Command Line
- Configuration Files
- OpenAPI
- Compatibility Catalog
- Secure
- Monitoring and Alerts
- Error Codes
- Glossary
- Example
- Troubleshoot
- Release Notes
- Backup & Restore (BR)
- Point-in-Time Recovery
- TiDB Binlog
- TiCDC
- Dumpling
- sync-diff-inspector
- TiSpark
- Reference
- Cluster Architecture
- Key Monitoring Metrics
- Secure
- Privileges
- SQL
- SQL Language Structure and Syntax
- SQL Statements
ADD COLUMNADD INDEXADMINADMIN CANCEL DDLADMIN CHECKSUM TABLEADMIN CHECK [TABLE|INDEX]ADMIN SHOW DDL [JOBS|QUERIES]ADMIN SHOW TELEMETRYALTER DATABASEALTER INDEXALTER INSTANCEALTER PLACEMENT POLICYALTER TABLEALTER TABLE COMPACTALTER TABLE SET TIFLASH MODEALTER USERANALYZE TABLEBACKUPBATCHBEGINCHANGE COLUMNCOMMITCHANGE DRAINERCHANGE PUMPCREATE [GLOBAL|SESSION] BINDINGCREATE DATABASECREATE INDEXCREATE PLACEMENT POLICYCREATE ROLECREATE SEQUENCECREATE TABLE LIKECREATE TABLECREATE USERCREATE VIEWDEALLOCATEDELETEDESCDESCRIBEDODROP [GLOBAL|SESSION] BINDINGDROP COLUMNDROP DATABASEDROP INDEXDROP PLACEMENT POLICYDROP ROLEDROP SEQUENCEDROP STATSDROP TABLEDROP USERDROP VIEWEXECUTEEXPLAIN ANALYZEEXPLAINFLASHBACK TABLEFLUSH PRIVILEGESFLUSH STATUSFLUSH TABLESGRANT <privileges>GRANT <role>INSERTKILL [TIDB]LOAD DATALOAD STATSMODIFY COLUMNPREPARERECOVER TABLERENAME INDEXRENAME TABLEREPLACERESTOREREVOKE <privileges>REVOKE <role>ROLLBACKSAVEPOINTSELECTSET DEFAULT ROLESET [NAMES|CHARACTER SET]SET PASSWORDSET ROLESET TRANSACTIONSET [GLOBAL|SESSION] <variable>SHOW ANALYZE STATUSSHOW [BACKUPS|RESTORES]SHOW [GLOBAL|SESSION] BINDINGSSHOW BUILTINSSHOW CHARACTER SETSHOW COLLATIONSHOW [FULL] COLUMNS FROMSHOW CONFIGSHOW CREATE PLACEMENT POLICYSHOW CREATE SEQUENCESHOW CREATE TABLESHOW CREATE USERSHOW DATABASESSHOW DRAINER STATUSSHOW ENGINESSHOW ERRORSSHOW [FULL] FIELDS FROMSHOW GRANTSSHOW INDEX [FROM|IN]SHOW INDEXES [FROM|IN]SHOW KEYS [FROM|IN]SHOW MASTER STATUSSHOW PLACEMENTSHOW PLACEMENT FORSHOW PLACEMENT LABELSSHOW PLUGINSSHOW PRIVILEGESSHOW [FULL] PROCESSSLISTSHOW PROFILESSHOW PUMP STATUSSHOW SCHEMASSHOW STATS_HEALTHYSHOW STATS_HISTOGRAMSSHOW STATS_METASHOW STATUSSHOW TABLE NEXT_ROW_IDSHOW TABLE REGIONSSHOW TABLE STATUSSHOW [FULL] TABLESSHOW [GLOBAL|SESSION] VARIABLESSHOW WARNINGSSHUTDOWNSPLIT REGIONSTART TRANSACTIONTABLETRACETRUNCATEUPDATEUSEWITH
- 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
- Locking Functions
- Information Functions
- JSON Functions
- Aggregate (GROUP BY) Functions
- Window Functions
- Miscellaneous Functions
- Precision Math
- Set Operations
- List of Expressions for Pushdown
- TiDB Specific Functions
- Clustered Indexes
- Constraints
- Generated Columns
- SQL Mode
- Table Attributes
- Transactions
- Garbage Collection (GC)
- Views
- Partitioning
- Temporary Tables
- Cached Tables
- Character Set and Collation
- Placement Rules in SQL
- System Tables
mysql- INFORMATION_SCHEMA
- Overview
ANALYZE_STATUSCLIENT_ERRORS_SUMMARY_BY_HOSTCLIENT_ERRORS_SUMMARY_BY_USERCLIENT_ERRORS_SUMMARY_GLOBALCHARACTER_SETSCLUSTER_CONFIGCLUSTER_HARDWARECLUSTER_INFOCLUSTER_LOADCLUSTER_LOGCLUSTER_SYSTEMINFOCOLLATIONSCOLLATION_CHARACTER_SET_APPLICABILITYCOLUMNSDATA_LOCK_WAITSDDL_JOBSDEADLOCKSENGINESINSPECTION_RESULTINSPECTION_RULESINSPECTION_SUMMARYKEY_COLUMN_USAGEMETRICS_SUMMARYMETRICS_TABLESPARTITIONSPLACEMENT_POLICIESPROCESSLISTREFERENTIAL_CONSTRAINTSSCHEMATASEQUENCESSESSION_VARIABLESSLOW_QUERYSTATISTICSTABLESTABLE_CONSTRAINTSTABLE_STORAGE_STATSTIDB_HOT_REGIONSTIDB_HOT_REGIONS_HISTORYTIDB_INDEXESTIDB_SERVERS_INFOTIDB_TRXTIFLASH_REPLICATIKV_REGION_PEERSTIKV_REGION_STATUSTIKV_STORE_STATUSUSER_PRIVILEGESVARIABLES_INFOVIEWS
METRICS_SCHEMA
- UI
- TiDB Dashboard
- Overview
- Maintain
- Access
- Overview Page
- Cluster Info Page
- Top SQL Page
- Key Visualizer Page
- Metrics Relation Graph
- SQL Statements Analysis
- Slow Queries Page
- Cluster Diagnostics
- Monitoring Page
- Search Logs Page
- Instance Profiling
- 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
- Release Timeline
- TiDB Versioning
- TiDB Installation Packages
- v6.2
- v6.1
- v6.0
- v5.4
- v5.3
- v5.2
- v5.1
- v5.0
- v4.0
- v3.1
- v3.0
- v2.1
- v2.0
- v1.0
- Glossary
TiDB Dashboard Cluster Diagnostics Page
Diagnostics in TiDB Dashboard is still an experimental feature. It is NOT recommended that you use it in the production environment.
The cluster diagnostics feature in TiDB Dashboard diagnoses the problems that might exist in a cluster within a specified time range, and summarizes the diagnostic results and the cluster-related load monitoring information into a diagnostic report. This diagnostic report is in the form of a web page. You can browse the page offline and circulate this page link after saving the page from a browser.
The cluster diagnostics feature depends on Prometheus deployed in the cluster. For details about how to deploy this monitoring component, see the TiUP deployment document. If no monitoring component is deployed in the cluster, the generated diagnostic report will indicate a failure.
Access the page
You can use one of the following methods to access the cluster diagnostics page:
After logging into TiDB Dashboard, click Cluster Diagnostics on the left navigation menu:

Visit
http://127.0.0.1:2379/dashboard/#/diagnosein your browser. Replace127.0.0.1:2379with the actual PD address and port number.
Generate diagnostic report
To diagnose a cluster within a specified time range and check the cluster load, you can take the following steps to generate a diagnostic report:
- Set the Range Start Time, such as
2020-05-21 14:40:00. - Set the Range Duration, such as
10 min. - Click Start.

It is recommended that the Range Duration of the report is between 1 minute and 60 minutes. This Range Duration cannot exceed 60 minutes.
The steps above generate a diagnostic report for the time range from 2020-05-21 14:40:00 to 2020-05-21 14:50:00. After clicking Start, you can see the interface below. Progress is the progress bar of the diagnostic report. After the report is generated, click View Full Report.

Generate comparison report
If a system exception occurs at a certain point, for example, QPS jitter or higher latency, a diagnostic report can be generated. Particularly, this report compares the system in the abnormal time range with the system in the normal time range. For example:
- Abnormal time range:
2020-05-21 14:40:00-2020-05-21 14:45:00. Within this time range, the system is abnormal. - Normal time range:
2020-05-21 14:30:00-2020-05-21 14:35:00. Within this time range, the system is normal.
You can take the following steps to generate a comparison report for the two time ranges above:
- Set the Range Start Time, which is the start time of the range in which the system becomes abnormal, such as
2020-05-21 14:40:00. - Set the Range Duration. Generally, this duration is the duration of system anomalies, such as 5 minutes.
- Enable Compare by baseline.
- Set the Baseline Range Start Time, which is the start time of the range (to be compared with) in which the system is normal, such as
2020-05-21 14:30:00. - Click Start.

Then wait for the report to be generated and click View Full Report.
In addition, the historical diagnostic report is displayed in the list on the main page of the diagnostic report. You can click to view these historical reports directly.