prestodb/presto · error · PrestoException

GENERIC_INTERNAL_ERROR

GENERIC_INTERNAL_ERROR

Error message

Failed to parse document source

What it means

getNextPage wraps IOException from Jackson deserialization of an Elasticsearch hit's _source JSON into this PrestoException: a document in the index does not match the expected JSON structure and cannot be converted to the table schema.

Source

Thrown at presto-elasticsearch/src/main/java/com/facebook/presto/elasticsearch/ScanQueryPageSource.java:211

    public void close()
    {
        iterator.close();
    }

    @Override
    public Page getNextPage()
    {
        long size = 0;

        while (size < PageBuilderStatus.DEFAULT_MAX_PAGE_SIZE_IN_BYTES && iterator.hasNext()) {
            Hit hit = iterator.next();
            Map<String, Object> document;
            try {
                JsonData source = (JsonData) hit.source();
                document = mapper.readValue(source.toJson().toString(), new TypeReference<>() {});
            }
            catch (IOException e) {
                throw new PrestoException(GENERIC_INTERNAL_ERROR, "Failed to parse document source");
            }

            for (int i = 0; i < decoders.size(); i++) {
                String field = columns.get(i).getName();
                decoders.get(i).decode(hit, () -> getField(document, field), columnBuilders[i]);
            }

            if (hit.source() != null) {
                try {
                    String json = mapper.writeValueAsString(hit.source());
                    totalBytes += json.getBytes(StandardCharsets.UTF_8).length;
                }
                catch (JsonProcessingException e) {
                    throw new PrestoException(GENERIC_INTERNAL_ERROR, "Failed to serialize document source");
                }
            }

            completedPositions += 1;

View on GitHub (pinned to 55bb57d202)

Solutions

1. Check that the index mapping and stored _source are valid JSON
2. Reindex documents with malformed sources
3. Verify field types in the index mapping match expectations

When it happens

Trigger: Thrown at presto-elasticsearch/src/main/java/com/facebook/presto/elasticsearch/ScanQueryPageSource.java:211 when the library encounters an invalid state.

Common situations: See trigger scenarios.

Understand the failure class

• Parsing and encoding errors: unexpected token, malformed input — why parsers reject input and how to find the real culprit.

AI-assisted analysis of prestodb/presto@55bb57d202 (2026-09-04). Data as JSON: /api/errors/038937d0623821bf. Report an issue: GitHub.