risingwavelabs/risingwave · error

OpenDAL is required

Error message

OpenDAL is required

What it means

The migration tool builds a remote object store from the given URL and requires the resulting backend to be an OpenDAL-backed store, since the list/copy rewrite logic uses OpenDAL APIs. Any other ObjectStoreImpl variant causes this error.

Source

Thrown at src/ctl/src/cmd_impl/hummock/migrate_legacy_object.rs:56

    println!("Normalized source_dir: {source_dir}.");
    println!("Normalized target_dir: {target_dir}.");
    if source_dir.is_empty() || target_dir.is_empty() {
        return Err(anyhow!("the source_dir and target_dir must not be empty"));
    }
    if target_dir.starts_with(source_dir) {
        return Err(anyhow!("the target_dir must not include source_dir"));
    }
    let mut config = ObjectStoreConfig::default();
    config.s3.developer.use_opendal = true;
    let store = build_remote_object_store(
        &url,
        ObjectStoreMetrics::unused().into(),
        "migrate_legacy_object",
        config.into(),
    )
    .await;
    let ObjectStoreImpl::Opendal(opendal) = store else {
        return Err(anyhow!("OpenDAL is required"));
    };
    let mut iter = opendal.list(source_dir, None, None).await?;
    let mut count = 0;
    println!("Migration is started: from {source_dir} to {target_dir}.");
    let mut from_to = Vec::with_capacity(concurrency as usize);
    let timer = Instant::now();
    while let Some(object) = iter.next().await {
        let object = object?;
        if !VALID_OBJECT_ID_SUFFIXES
            .iter()
            .any(|suffix| object.key.ends_with(suffix))
        {
            let legacy_path = object.key;
            assert_eq!(
                &legacy_path[..source_dir.len()],
                source_dir,
                "{legacy_path} versus {source_dir}"
            );

View on GitHub (pinned to 6469eb736d)

Solutions

1. Provide an object store URL that builds an OpenDAL backend (opendal s3 url)
2. Check the rw build/feature flags enable OpenDAL object store support
3. Inspect build_remote_object_store's URL mapping to confirm which URL forms yield ObjectStoreImpl::Opendal

Example fix

null

let store = build_remote_object_store(&url, ...).await;
if !matches!(store, ObjectStoreImpl::Opendal(_)) {
    eprintln!("url {} does not yield an OpenDAL backend", url);
    return;
}

When it happens

Trigger: Running migrate-legacy-object with a store URL that resolves to a non-OpenDAL implementation (e.g. native S3 client instead of OpenDAL S3).

Common situations: Using an s3:// URL while the OpenDAL developer option is not applied to the backend selection, or pointing at an in-memory/local store type.

Understand the failure class

Background: "is not a compatible type" / "cannot merge" errors: when a value's type doesn't match what the library requires — this error's family across 65 libraries.

Related errors

• the source_dir and target_dir must not be empty
• the target_dir must not include source_dir
• Storage error: {0}
• Failed to spill out to disk
• Unsupported warehouse scheme: {}

AI-assisted analysis of risingwavelabs/risingwave@6469eb736d (2026-09-11). Data as JSON: /api/errors/2ce4e67e23c3e249. Report an issue: GitHub.