apache/seatunnel · error · IllegalStateException

Failed to read AmazonDocumentDB data from database [%s], col

Error message

Failed to read AmazonDocumentDB data from database [%s], collection [%s]

What it means

AmazonDocumentDBSourceReader.fetchNextDocument iterates the MongoDB cursor to fetch the next BsonDocument. On any exception during cursor.next() or the underlying fetch, it closes the cursor and rethrows as IllegalStateException naming the database and collection, so the reader fails rather than returning corrupted data.

Source

Thrown at seatunnel-connectors-v2/connector-amazondocumentdb/src/main/java/org/apache/seatunnel/connectors/seatunnel/amazondocumentdb/source/AmazonDocumentDBSourceReader.java:191

    BsonDocument fetchNextDocument(AmazonDocumentDBSourceSplit split) {
        try {
            if (cursor == null) {
                FindIterable<BsonDocument> findIterable =
                        collection.find(BsonDocument.parse(split.getMatchQuery()));
                if (split.getProjection() != null) {
                    findIterable.projection(BsonDocument.parse(split.getProjection()));
                }
                cursor = findIterable.batchSize(config.getFetchSize()).iterator();
            }
            if (cursor.hasNext()) {
                return cursor.next();
            }
            closeCursor();
            return null;
        } catch (Exception e) {
            closeCursor();
            throw new IllegalStateException(
                    String.format(
                            "Failed to read AmazonDocumentDB data from database [%s], collection [%s]",
                            config.getDatabase(), config.getCollection()),
                    e);
        }
    }

    private void closeCursor() {
        if (cursor != null) {
            cursor.close();
            cursor = null;
        }
    }

    private void finishCurrentSplit() {
        LOG.info("AmazonDocumentDB reader [{}] finished source scan", context.getIndexOfSubtask());
        currentSplit = null;
    }

View on GitHub (pinned to cf67b549a7)

Solutions

Retry the job/reader; enable retryable reads on the MongoDB client (retryReads=true).
Tune cursor behavior: use smaller batch size or add an index on the filter/sort so cursors complete faster and avoid server-side timeout.
Check DocumentDB cluster health and network stability between workers and the cluster.
Inspect the cause chain for the driver error (MongoCursorNotFoundException, MongoTimeoutException) and address that root cause.

Example fix

// before
mongodb://host:27017
// after: enable retryable reads and tighter timeouts
mongodb://host:27017/?retryReads=true&maxIdleTimeMS=120000

Defensive patterns

Strategy: retry

Validate before calling

null

Type guard

null

Try / catch

try { doc = reader.fetchNextDocument(); } catch (IllegalStateException e) { if (isTransient(e.getCause())) { restartReaderWithBackoff(); } else { throw e; } }

Prevention

Enable retryReads=true and sane socket/connect timeouts on the connection string.
Keep cursors short-lived; avoid full-collection scans without indexes; set appropriate maxIdleTimeMS.
Monitor DocumentDB failovers and network stability; design readers to be restartable (checkpointing).

When it happens

Trigger: Cursor.next() throws (network drop to DocumentDB, cursor timed out / cursor id not found, replica-set state change, query killed server-side) while polling the next batch.

Common situations: Long-running read interrupted by DocumentDB idle-cursor timeout; network blip between the SeaTunnel worker and DocumentDB; failover of the DocumentDB primary during the scan; too-large batch causing memory/timeout pressure.

Understand the failure class

Background: Database query failed: Internal Server Error 500s wrapping SQL, Prisma, and connection failures — what to check first — this error's family across 16 libraries.

Related errors

AI-assisted analysis of apache/seatunnel@cf67b549a7 (2026-09-10). Data as JSON: /api/errors/62407ba0e1f594b5. Report an issue: GitHub.