databendlabs/databend · error

Invalid config.rpc

Error message

Invalid config.rpc: {}

What it means

In metabench's run_benchmark_once, the cmd argument is dispatched over a fixed list of benchmark commands; any unrecognized cmd (driven by an invalid config.rpc value) hits unreachable!("Invalid config.rpc: {}"), crashing the benchmark binary. It guards the assumption that the config only ever names supported benchmark commands.

Solutions

1. Check the config.rpc/cmd value against the commands handled in run_benchmark_once and fix the typo.
2. Add the missing dispatch arm if it is a new benchmark command.
3. Convert the unreachable! into a graceful error that lists valid options.

Example fix

// before
_ => unreachable!("Invalid config.rpc: {}", rpc),
// after
_ => panic!("Invalid config.rpc: {} (supported: upsert, get, list, semaphore, ...)", rpc),

let supported = ["upsert", "get", "list", "semaphore", "copy"];
if !supported.contains(&rpc.as_str()) {
    panic!("Invalid config.rpc: {} (expected one of {:?})", rpc, supported);
}

_ => Err(anyhow::anyhow!(
    "Invalid config.rpc: {} (valid: upsert, get, list, semaphore)", rpc
)),

When it happens

Trigger: Setting rpc/cmd in the metabench config to a value outside the supported set (e.g. a typo like 'upserts' instead of 'upsert', or a command removed from the dispatcher) and running the benchmark.

Common situations: Hand-edited benchmark configs; configs reused across metabench versions where a command was renamed or removed; adding a new benchmark to the config before implementing its dispatch arm.

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

• {e}
• get_input_read_buffer_size should not fail
• {}
• Temp table id used up
• Invalid temp table desc

AI-assisted analysis of databendlabs/databend@288d84d76e (2026-09-11). Data as JSON: /api/errors/0bca4fc58904cb66. Report an issue: GitHub.

Appendix: source

Thrown at src/meta/binaries/metabench/main.rs:410

        benchmark_upsert(client, prefix, client_num, i).await
    } else if cmd == "table" {
        benchmark_table(client, prefix, client_num, i).await
    } else if cmd == "create_tables" {
        benchmark_create_tables(client, prefix, client_num, i, param).await
    } else if cmd == "batch_create_tables" {
        benchmark_batch_create_tables(client, prefix, client_num, i, param).await
    } else if cmd == "get_table" {
        benchmark_get_table(client, prefix, client_num, i).await
    } else if cmd == "get_table_rand" {
        benchmark_get_table_rand(client, client_num, i, param).await
    } else if cmd == "table_copy_file" {
        benchmark_table_copy_file(client, prefix, client_num, i, param).await
    } else if cmd == "semaphore" {
        benchmark_semaphore(client, prefix, client_num, i, param).await
    } else if cmd == "list" {
        benchmark_list(client, prefix, client_num, i, param).await
    } else {
        unreachable!("Invalid config.rpc: {}", rpc);
    }
}

async fn benchmark_upsert(client: &MetaStore, prefix: u64, client_num: u64, i: u64) -> bool {
    let node_key = || format!("{}-{}-{}", prefix, client_num, i);

    let seq = MatchSeq::Any;
    let value = Operation::Update(node_key().as_bytes().to_vec());

    let res = client
        .upsert_kv(UpsertKV::new(node_key(), seq, value, None))
        .await;

    print_res(i, "upsert_kv", &res);
    res.is_ok()
}

async fn benchmark_table(client: &MetaStore, prefix: u64, client_num: u64, i: u64) -> bool {

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