influxdata/influxdb · error · TableIndexError

Cannot merge table indices with mismatched identifiers

Error message

Cannot merge table indices with mismatched identifiers: {expected} != {actual}

What it means

TableIndexError::MergeMismatch is raised when merging two table indices whose TableIndexId (database/table identifiers plus node identity) do not match. Index merge logic assumes both inputs describe the same table index; a mismatch would silently corrupt the merged index, so it is rejected eagerly. This is an invariant violation rather than an I/O failure.

Solutions

1. Log the expected and actual TableIndexId from the error fields to identify which object is mismatched.
2. Verify the index is loaded/parsed from the correct object store path for that (db_id, table_id).
3. Clear the corrupted/stale index object from the store and rebuild it from snapshots.
4. Audit code that constructs or deserializes TableIndexId to ensure it comes from the same source as the index being merged.

Example fix

// before
let merged = local_index.merge(loaded_index); // may panic/err at runtime
// after
assert_eq!(local_index.id(), loaded_index.id(), "refusing to merge indices for different tables");
let merged = local_index.merge(loaded_index);

fn can_merge(expected: &TableIndexId, actual: &TableIndexId) -> bool { expected == actual }
// call before merging; if false, skip or rebuild the index instead of merging

match result {
    Err(TableIndexError::MergeMismatch { expected, actual }) => {
        error!(?expected, ?actual, "index id mismatch; rebuilding index from snapshots");
        rebuild_index_from_snapshots().await
    }
    other => other,
}

When it happens

Trigger: Calling the merge operation (e.g. merging a loaded persisted index with a locally built one during update) where expected != actual TableIndexId — typically when a snapshot/index file belongs to a different database or table than the in-memory index being updated.

Common situations: Reusing or mis-pointing index cache paths across databases/tables; restoring an index snapshot into the wrong database; concurrency bugs where two tables' updates interleave; node identifier changes after failover with stale files.

Understand the failure class

Background: "This is a bug, please report it": internal invariant violations, unreachable panics, and SNH errors explained — this error's family across 47 libraries.

Related errors

• ' ' is a reserved column
• auto field family exists
• By the point that we're doing partitioning, we should've…
• cache error
• can only accept once

AI-assisted analysis of influxdata/influxdb@06200ef96b (2026-09-19). Data as JSON: /api/errors/62824d20698319de. Report an issue: GitHub.

Appendix: source

Thrown at influxdb3_write/src/table_index.rs:49

    #[error("Failed to list table index snapshots from object store")]
    ListSnapshots(#[source] object_store::Error),

    #[error("Failed to list table indices from object store")]
    ListIndices(#[source] object_store::Error),

    #[error("Failed to load table index snapshot from object store")]
    LoadSnapshot(#[source] object_store::Error),

    #[error("Failed to deserialize table index snapshot")]
    DeserializeSnapshot(#[source] serde_json::Error),

    #[error("Failed to persist table index to object store")]
    PersistIndex(#[source] object_store::Error),

    #[error("Failed to delete table index snapshot from object store")]
    DeleteSnapshot(#[source] object_store::Error),

    #[error("Cannot merge table indices with mismatched identifiers: {expected} != {actual}")]
    MergeMismatch {
        expected: TableIndexId,
        actual: TableIndexId,
    },

    #[error("Failed to parse table index path from object store path")]
    TableIndexPath(#[source] crate::paths::PathError),

    #[error("Failed to parse table index snapshot path from object store path")]
    TableIndexSnapshotPath(#[source] crate::paths::PathError),

    #[error("Failed to update table index: join task failed")]
    UpdateTaskFailed(#[source] tokio::task::JoinError),

    #[error("Object meta is missing filename")]
    MissingFilename,

    #[error("Failed to parse snapshot sequence number from filename")]

View on GitHub (pinned to 06200ef96b)