What causes "`compaction_task_id_refill_capacity` must be greater than 0" in risingwavelabs/risingwave?

Set `meta.compaction_task_id_refill_capacity` to a positive integer in the config file.

`compaction_task_id_refill_capacity` must be greater than 0

Error message

`compaction_task_id_refill_capacity` must be greater than 0

What it means

validate_config in src/meta/node/src/lib.rs:644 panics when `config.meta.compaction_task_id_refill_capacity` is 0. This capacity controls the token pool used to assign compaction task IDs; an empty pool would deadlock compaction scheduling, so it is rejected at startup.

Source

Thrown at src/meta/node/src/lib.rs:644

        panic!("{}", error_msg);
    }

    if config.meta.checkpoint_read_chunk_size == 0 {
        let error_msg = "`checkpoint_read_chunk_size` must be greater than 0";
        tracing::error!(error_msg);
        panic!("{}", error_msg);
    }

    if config.meta.checkpoint_read_max_in_flight_chunks == 0 {
        let error_msg = "`checkpoint_read_max_in_flight_chunks` must be greater than 0";
        tracing::error!(error_msg);
        panic!("{}", error_msg);
    }

    if config.meta.compaction_task_id_refill_capacity == 0 {
        let error_msg = "`compaction_task_id_refill_capacity` must be greater than 0";
        tracing::error!(error_msg);
        panic!("{}", error_msg);
    }

    if config.meta.iceberg_compaction_report_timeout_sec == 0 {
        let error_msg = "`iceberg_compaction_report_timeout_sec` must be greater than 0";
        tracing::error!(error_msg);
        panic!("{}", error_msg);
    }

    if config.meta.iceberg_compaction_config_refresh_interval_sec == 0 {
        let error_msg = "`iceberg_compaction_config_refresh_interval_sec` must be greater than 0";
        tracing::error!(error_msg);
        panic!("{}", error_msg);
    }
}

View on GitHub (pinned to 6469eb736d)

Solutions

Set `meta.compaction_task_id_refill_capacity` to a positive integer in the config file.
Remove the custom override to use the default capacity.
Re-run `./risedev generate-example-config` after config definition changes to keep examples valid.

Example fix

// before
[meta]
compaction_task_id_refill_capacity = 0

// after
[meta]
compaction_task_id_refill_capacity = 1000

Defensive patterns

Strategy: validation

Validate before calling

assert!(cfg.meta.compaction_task_id_refill_capacity > 0, "compaction_task_id_refill_capacity must be > 0");

Prevention

Treat capacity knobs as positive integers in all config tooling.
Validate config files with a schema validator before launching meta nodes.
Copy values only from the checked-in example.toml, not ad-hoc snippets.

When it happens

Trigger: Meta node startup with `meta.compaction_task_id_refill_capacity` set to 0 in the config.

Common situations: Tuning compaction scheduling knobs without understanding the ID refill pool, or copying partial config snippets.

Understand the failure class

Background: "Invalid value" and "allowed values are" config errors: what your library rejected and how to fix it — this error's family across 41 libraries.

Related errors

AI-assisted analysis of risingwavelabs/risingwave@6469eb736d (2026-09-11). Data as JSON: /api/errors/ef06a3cdc84f22d8. Report an issue: GitHub.