HiveServer2 table comment metadata failed

Error message

HiveServer2 table comment metadata failed (%v); table listing fallback failed: %w

What it means

getTableComment fetches a table's comment via HiveServer2 metadata (GetHiveTables filtered by name). If that fails it falls back to a full listTables call and matches the table by name. This error is raised only when both the metadata call and the table-listing fallback fail, embedding the metadata error and wrapping the fallback error.

Solutions

Address the root metadata error shown first (permissions or connectivity)
Ensure the user can run SHOW TABLES / metadata listing on the target schema
Reconnect if both failures are transport-related (connection dropped)
If comments are optional, treat the failure as non-fatal and degrade to no comment

Defensive patterns

Strategy: fallback

Try / catch

comment, err := server.getTableComment(schema, table)
if err != nil && strings.Contains(err.Error(), "table listing fallback failed") {
    log.Printf("comment unavailable for %s.%s: %v", schema, table, err)
    return nil, nil // degrade gracefully
}

Prevention

Grant catalog/metadata read privileges to the connect user
Check connectivity before bulk comment retrieval
Tolerate missing comments since absent tables return nil, nil

When it happens

Trigger: get_table_comment RPC where the metadata API fails (permissions/transport) and the subsequent listTables fallback (which itself may hit the SHOW TABLES path) also fails — typically permission or connectivity issues on the schema.

Common situations: Service account lacking read access to the schema catalog; broken connection causing both attempts to fail; restricted HiveServer2 deployments where metadata calls are disabled.

Related errors

AI-assisted analysis of t8y2/dbx@c0390bff16 (2026-09-05). Data as JSON: /api/errors/49c10722cbdeaea9. Report an issue: GitHub.

Appendix: source

Thrown at agents/drivers/hive-go/metadata.go:671

			IsNullable: true,
			Comment:    comment,
		})
	}
	return values, nil
}

func (server *server) getTableComment(schema, table string) (*string, error) {
	if strings.TrimSpace(table) == "" {
		return nil, errors.New("table is required")
	}
	schema = firstNonEmpty(schema, server.config.Database)
	metadataResult, err := server.hiveMetadata(func(ctx context.Context, provider gohive.MetadataProvider) (gohive.MetadataResult, error) {
		return provider.GetHiveTables(ctx, schema, table, nil)
	})
	if err != nil {
		tables, listErr := server.listTables(schema, metadataListConstraints{Filter: table})
		if listErr != nil {
			return nil, fmt.Errorf("HiveServer2 table comment metadata failed (%v); table listing fallback failed: %w", err, listErr)
		}
		for _, candidate := range tables {
			if strings.EqualFold(candidate.Name, table) {
				return candidate.Comment, nil
			}
		}
		return nil, nil
	}
	rows := newHiveMetadataRows(metadataResult)
	for _, row := range rows.rows {
		if strings.EqualFold(metadataString(rows.value(row, "TABLE_NAME")), table) {
			return optionalString(metadataString(rows.value(row, "REMARKS", "COMMENT"))), nil
		}
	}
	return nil, nil
}

func (server *server) listDataTypes() ([]string, error) {

View on GitHub (pinned to c0390bff16)