xai-org/x-algorithm · critical

Shard {}: {}

Error message

Shard {}: {}

What it means

Error message produced by reshard_col_to_row_and_upload when one or more shard uploads fail during column-to-row resharding; it aggregates per-shard errors as 'Shard {i}: {err}'. The underlying cause is in each shard's error text (network, S3/HDFS auth, checksum, etc.).

Source

Thrown at phoenix/crates/serving/xai-recsys-engine/src/storage_util.rs:1614

                        shard_idx,
                        max_retries,
                        last_error.unwrap_or_else(|| "unknown".to_string())
                    ))
                })
            })
            .collect();

        join_all(futures)
            .await
            .into_iter()
            .map(|r| r.map_err(|e| format!("Task join error: {}", e)).and_then(|r| r))
            .collect()
    });

    let failures: Vec<_> = upload_results
        .iter()
        .enumerate()
        .filter_map(|(i, r)| r.as_ref().err().map(|e| (i, e.clone())))
        .collect();

    if !failures.is_empty() {
        let error_msg = failures
            .iter()
            .map(|(i, e)| format!("Shard {}: {}", i, e))
            .collect::<Vec<_>>()
            .join("; ");
        return Err(pyo3::exceptions::PyRuntimeError::new_err(format!(
            "Failed to upload {} shards: {}",
            failures.len(),
            error_msg
        )));
    }

    info!(
        "Successfully resharded and uploaded {} row shards to {}",
        num_output_shards, output_url

View on GitHub (pinned to 24c60942c5)

Solutions

1. Read the per-shard error text to identify the root cause (auth vs network vs path)
2. Retry the operation — transient upload failures usually succeed on rerun
3. Verify storage credentials, bucket/path and urls argument
4. Check local disk space for temp shard files if the error mentions I/O

# pre-flight: verify credentials and reachability of the upload target
# (e.g. head bucket / check urls) before resharding

for attempt in range(3):
    try: reshard_col_to_row_and_upload(...); break
    except Exception as e:
        if 'Shard ' in str(e) and attempt < 2: time.sleep(2 ** attempt); continue
        raise

When it happens

Trigger: Calling reshard_col_to_row_and_upload where any parallel upload of a resharded shard fails — e.g. remote storage unreachable, expired credentials, wrong bucket/path, or disk full when writing temp shards.

Common situations: Uploading to object storage with expired tokens; misconfigured URL prefix; transient network flakiness across many shards causing at least one failure (the whole operation then errors).

AI-assisted analysis of xai-org/x-algorithm@24c60942c5 (2026-08-28). Data as JSON: /api/errors/9c72b2197ae58277. Report an issue: GitHub.