TiDB-Lightning Monitoring

Both tidb-lightning and tikv-importer supports metrics collection via Prometheus. This document introduces the monitor configuration and monitoring metrics of TiDB-Lightning.

Monitor configuration

  • If TiDB-Lightning is installed using TiDB-Ansible, simply add the servers to the [monitored_servers] section in the inventory.ini. Then the Prometheus server can collect their metrics.
  • If TiDB-Lightning is manually installed, follow the instructions below.

tikv-importer

tikv-importer v2.1 uses Pushgateway to deliver metrics. Configure tikv-importer.toml to recognize the Pushgateway with the following settings:

[metric]

# The Prometheus client push job name.
job = "tikv-importer"

# The Prometheus client push interval.
interval = "15s"

# The Prometheus Pushgateway address.
address = ""

tidb-lightning

The metrics of tidb-lightning can be gathered directly by Prometheus as long as it is discovered. You can set the metrics port in tidb-lightning.toml:

[lightning]
# HTTP port for debugging and Prometheus metrics pulling (0 to disable)
pprof-port = 10089

...

You need to configure Prometheus to make it discover the tidb-lightning server. For instance, you can directly add the server address to the scrape_configs section:

...
scrape_configs:
  - job_name: 'tidb-lightning'
    static_configs:
      - targets: ['192.168.20.10:10089']

Monitoring metrics

This section explains the monitoring metrics of tikv-importer and tidb-lightning.

tikv-importer

Metrics provided by tikv-importer are listed under the namespace tikv_import_*.

  • tikv_import_rpc_duration (Histogram)

    Bucketed histogram of importing RPC duration. Labels:

    • request: RPC name, e.g. open_engine, import_engine, etc.
    • result: ok / error
  • tikv_import_write_chunk_bytes (Histogram)

    Bucketed histogram of importing write chunk bytes.

  • tikv_import_write_chunk_duration (Histogram)

    Bucketed histogram of importing write chunk duration.

  • tikv_import_upload_chunk_bytes (Histogram)

    Bucketed histogram of importing upload chunk bytes.

  • tikv_import_upload_chunk_duration (Histogram)

    Bucketed histogram of importing upload chunk duration.

tidb-lightning

Metrics provided by tidb-lightning are listed under the namespace lightning_*.

  • lightning_importer_engine (Counter)

    Counting open and closed engine files. Labels:

    • type: open / closed
  • lightning_idle_workers (Gauge)

    Counting idle workers. Values should be less than the *-concurrency settings and are typically zero. Labels:

    • name: table / region / io
  • lightning_kv_encoder (Counter)

    Counting open and closed KV encoders. KV encoders are in-memory TiDB instances that convert SQL INSERT statements into KV pairs. The net values need to be bounded in a healthy situation. Labels:

    • type: open / closed
  • lightning_tables (Counter)

    Counting number of tables processed and their status. Labels:

    • state: pending / written / closed / imported / altered_auto_inc / checksum / analyzed / completed
    • result: success / failure
  • lightning_chunks (Counter)

    Counting number of chunks processed and their status. Labels:

    • state: estimated / pending / running / finished / failed
  • lightning_import_seconds (Histogram)

    Bucketed histogram of the time needed to import a table.

  • lightning_block_read_seconds (Histogram)

    Bucketed histogram of the time needed to read a block of SQL rows from the data source.

  • lightning_block_read_bytes (Histogram)

    Bucketed histogram of the size of a block of SQL rows.

  • lightning_block_encode_seconds (Histogram)

    Bucketed histogram of the time needed to encode a block of SQL rows into KV pairs.

  • lightning_block_deliver_seconds (Histogram)

    Bucketed histogram of the time needed to deliver a block of KV pairs.

  • lightning_block_deliver_bytes (Histogram)

    Bucketed histogram of the size of a block of KV pairs.

  • lightning_chunk_parser_read_block_seconds (Histogram)

    Bucketed histogram of the time needed by the data file parser to read a block.

  • lightning_chunk_parser_read_row_seconds (Histogram)

    Bucketed histogram of the time needed by the data file parser to read a row.

  • lightning_checksum_seconds (Histogram)

    Bucketed histogram of the time taken to compute the checksum of a table.

  • lightning_apply_worker_seconds (Histogram)

    Bucketed histogram of the time taken to acquire an idle worker. Labels:

    • name: table / region / io