Elasticsearch Source config warn: when both 'index' and…

Error message

Elasticsearch Source config warn: when both 'index' and 'index_list' are present in the configuration, only the 'index_list' configuration will take effect

What it means

When an Elasticsearch source config contains both 'index' and 'index_list', the connector logs this warning because only 'index_list' is honored and the 'index' value is silently ignored. This prevents ambiguous multi/single-source setup.

Solutions

Remove the 'index' key when 'index_list' is present
Or remove 'index_list' if you actually want a single index read
Confirm in logs which index set will be used

Example fix

// before
index = "orders_v1"
index_list = ["orders_v1", "orders_v2"]
// after (multi-index)
index_list = ["orders_v1", "orders_v2"]

Defensive patterns

Strategy: validation

Validate before calling

// reject configs with both keys
if (config.hasPath("index") && config.hasPath("index_list")) {
    throw new IllegalArgumentException("Set only one of 'index' or 'index_list'");
}

Prevention

Keep a single canonical index key per job config
When scaling to multi-index, delete the old 'index' entry
Add a config lint step in CI for ES job files

When it happens

Trigger: Setting index = "..." and index_list = [...] simultaneously in the Elasticsearch source configuration, e.g. after extending a single-index job to multiple indices.

Common situations: Copy-pasted configs where the old single-index key was not removed; templated configs that always emit both keys.

Understand the failure class

Background: Conflicting config options: "cannot be used together" — configuration validation errors across open-source libraries — this error's family across 162 libraries.

Related errors

AI-assisted analysis of apache/seatunnel@cf67b549a7 (2026-09-10). Data as JSON: /api/errors/6b67dff9870eda26. Report an issue: GitHub.

Appendix: source

Thrown at seatunnel-connectors-v2/connector-elasticsearch/src/main/java/org/apache/seatunnel/connectors/seatunnel/elasticsearch/source/ElasticsearchSource.java:79

@Slf4j
public class ElasticsearchSource
        implements SeaTunnelSource<
                        SeaTunnelRow, ElasticsearchSourceSplit, ElasticsearchSourceState>,
                SupportParallelism,
                SupportColumnProjection {

    private final List<ElasticsearchConfig> elasticsearchConfigList;
    private final ReadonlyConfig connectionConfig;

    public ElasticsearchSource(ReadonlyConfig config) {
        this.connectionConfig = config;
        boolean multiSource = config.getOptional(ElasticsearchSourceOptions.INDEX_LIST).isPresent();
        boolean singleSource = config.getOptional(ElasticsearchSourceOptions.INDEX).isPresent();

        if (multiSource && singleSource) {
            log.warn(
                    "Elasticsearch Source config warn: when both 'index' and 'index_list' are present in the configuration, only the 'index_list' configuration will take effect");
        }
        if (multiSource) {
            this.elasticsearchConfigList = createMultiSource(config);
        } else {
            this.elasticsearchConfigList =
                    Collections.singletonList(parseOneIndexQueryConfig(config));
        }
    }

    private List<ElasticsearchConfig> createMultiSource(ReadonlyConfig config) {
        List<Map<String, Object>> configMaps = config.get(ElasticsearchSourceOptions.INDEX_LIST);
        List<ReadonlyConfig> configList =
                configMaps.stream().map(ReadonlyConfig::fromMap).collect(Collectors.toList());
        List<ElasticsearchConfig> elasticsearchConfigList = new ArrayList<>(configList.size());
        for (ReadonlyConfig readonlyConfig : configList) {
            // NOTE: per-entry configs inside `index_list` are NOT validated by the factory's
            // OptionRule (which only validates the top-level config). If an entry is missing
            // `index`, or sets `search_type=SQL` without `sql_query`, parseOneIndexQueryConfig

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