risingwavelabs/risingwave · error

missing source id in source fragment {}

Error message

missing source id in source fragment {}

What it means

When the ensemble has a source entry fragment, render_actors_with_allocator requires a source ID recorded in fragment_source_ids for that fragment (needed to attach source splits to the rendered actors). If the mapping is missing, this error names the fragment ID.

Source

Thrown at src/meta/src/controller/scale.rs:1009

            }
            mask.contains(FragmentTypeFlag::Source) && !mask.contains(FragmentTypeFlag::Dml)
        });

        let actor_template = EnsembleActorTemplate::render_new(
            job,
            worker_map,
            entry_fragment_parallelism,
            database_resource_group,
            distribution_type,
            vnode_count,
        )?;

        let source_splits = match source_entry_fragment {
            Some(entry_fragment) => {
                let source_id = fragment_source_ids
                    .get(&entry_fragment.fragment_id)
                    .ok_or_else(|| {
                        anyhow!(
                            "missing source id in source fragment {}",
                            entry_fragment.fragment_id
                        )
                    })?;

                let entry_fragment_id = entry_fragment.fragment_id;

                let splits = fragment_splits_map
                    .get(&entry_fragment_id)
                    .cloned()
                    .unwrap_or_default();

                let splits: std::collections::BTreeMap<_, _> =
                    splits.into_iter().map(|s| (s.id(), s)).collect();
                let splits = actor_template.assign_splits(entry_fragment_id, splits);
                Some((splits, *source_id))
            }
            None => None,

View on GitHub (pinned to 6469eb736d)

Solutions

1. Check the catalog's source-fragment mapping for the reported fragment_id and restore/repair the mapping if the source still exists.
2. Exclude the stale source fragment or re-create the source so the mapping is regenerated.
3. Reload the context freshly after any DDL completes.
4. Report a bug if the mapping is missing with no history of source DDL.

for frag in source_entry_fragments {
    assert!(ctx.fragment_source_ids.contains_key(&frag.fragment_id),
            "source fragment {} lacks source id", frag.fragment_id);
}

fn has_source_mapping(ctx: &LoadedFragmentContext, frag_id: FragmentId) -> bool {
    ctx.fragment_source_ids.contains_key(&frag_id)
}

let Some(source_id) = ctx.fragment_source_ids.get(&entry_fragment.fragment_id) else {
    warn!("source fragment {} has no source mapping; skipping source splits", entry_fragment.fragment_id);
    return render_without_source_splits();
};

When it happens

Trigger: An ensemble includes a source entry fragment but the load stage did not populate fragment_source_ids for it — e.g. the fragment is classified as a source fragment yet has no corresponding source row, or the fragment-to-source mapping was lost in the catalog.

Common situations: Dropped/modified source connectors while fragment rows persist; jobs whose source fragments were rebuilt by an interrupted replace; version skew where older fragments lack source mapping metadata.

Understand the failure class

Background: "missing required argument" and "the following required arguments were not provided": what required-argument errors mean and how to fix them — this error's family across 20 libraries.

Related errors

• entry fragments {:?} have inconsistent parallelism settings
• fragments {:?} not found
• Multiple jobs found in no-shuffle ensemble
• streaming job {job_id} not found
• streaming job {job_id} not found in streaming_job_databases

AI-assisted analysis of risingwavelabs/risingwave@6469eb736d (2026-09-11). Data as JSON: /api/errors/852589a261c8fea5. Report an issue: GitHub.