Enable_resource_control configuration item tiflash

TiDB Ops & Admin
1

in Use Resource Control to Achieve Resource Isolation | PingCAP Docs

TiFlash: you can use the tidb_enable_resource_control system variable and the enable_resource_control configuration item (introduced in v7.4.0) to control whether to enable TiFlash resource control

I’m using tidb 7.5 now
how to check my current set up : tiflash enable_resource_control is on or off ?
and anyway to verify “Pipeline execution model” is used at run-time ?

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To check whether the enable_resource_control configuration item for TiFlash is enabled or disabled in TiDB 7.5, you can follow these steps:

  1. Check the TiFlash Configuration:

    • The enable_resource_control configuration item controls whether the TiFlash resource control feature is enabled. You can find this configuration in the tiflash-learner.toml file.
    • Open the tiflash-learner.toml file and look for the enable_resource_control setting. If it is set to true, then the TiFlash resource control feature is enabled. If it is set to false, then the feature is disabled.

  2. Verify Pipeline Execution Model:

    • To verify whether the Pipeline execution model is used at runtime, you can monitor the TiFlash logs or performance metrics during query execution.
    • When enable_resource_control is enabled, TiFlash uses the Pipeline execution model. You can observe the query execution behavior to see if it aligns with the characteristics of the Pipeline execution model, such as pipelined processing of data.

By checking the enable_resource_control configuration item in the tiflash-learner.toml file and monitoring the query execution behavior, you can determine if TiFlash resource control is enabled and if the Pipeline execution model is being used in your TiDB 7.5 setup.

3

more detail about “monitoring the query execution behavior” ? where to check it ? for example, TiDB dashboard → slow query ?

4

To monitor the query execution behavior and verify if the Pipeline execution model is being used in TiDB, you can follow these steps:

  1. Monitoring in Grafana Dashboard:

    • Access the Grafana dashboard for TiDB.
    • Look for relevant metrics related to query execution and performance. You can check metrics such as query execution time, query throughput, and resource utilization.
    • Specifically, pay attention to metrics that indicate the execution model being used, such as pipelined processing or batch processing.

  2. Slow Query Log:

    • Check the Slow Query Log in TiDB to identify queries that are taking longer to execute.
    • Slow queries may provide insights into the execution behavior and performance characteristics of the queries.
    • You can analyze the slow queries to see if they exhibit characteristics of the Pipeline execution model.

  3. TiDB Performance Schema:

    • Utilize the TiDB Performance Schema to gather detailed information about query execution.
    • The Performance Schema provides performance-related metrics at a granular level, allowing you to analyze query execution behavior.

By monitoring the Grafana dashboard, reviewing the Slow Query Log, and utilizing the Performance Schema in TiDB, you can observe query execution behavior and gather insights into whether the Pipeline execution model is being used effectively.

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can you give sample screenshots to your answer 1, 2 ?

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Sorry, I can only answer questions based on the official documentation. Let’s try another question.