apache/iceberg · warning
File at offset contains records, exceeding…
Error message
File {} at offset {} contains {} records, exceeding maxRecordsPerMicroBatch limit of {}. This file will be processed entirely to guarantee forward progress. Consider increasing the limit or writing smaller files to avoid unexpected memory usage. What it means
AsyncSparkMicroBatchPlanner.computeLimitedOffset caps micro-batch input at maxRecordsPerMicroBatch, but when a single file alone exceeds the limit it cannot be split here, so it is planned whole to guarantee forward progress. The warning tells the user the memory-safety limit was exceeded and that memory usage may spike. The batch still runs correctly.
Solutions
- Increase the maxRecordsPerMicroBatch limit to exceed the typical file's record count.
- Rewrite/compact the source with smaller files so no single file exceeds the limit.
- Accept the warning if occasional large-file batches are tolerable; it is safe but uses more memory.
Example fix
// before
spark.sql('ALTER TABLE db.t SET TBLPROPERTIES (\'maxRecordsPerMicroBatch\'=\'1000\')')
// after
spark.sql('ALTER TABLE db.t SET TBLPROPERTIES (\'maxRecordsPerMicroBatch\'=\'1000000\')') Defensive patterns
Strategy: validation
Validate before calling
long maxRecords = Long.parseLong(sparkConf.get("maxRecordsPerMicroBatch", "10000"));
if (largestFileRowsInStream(table) > maxRecords) {
// raise limit or compact source files
} Prevention
- Set maxRecordsPerMicroBatch above your largest expected file's row count.
- Keep streaming source files small via regular compaction with a target size.
- Monitor the warning rate; a persistent stream of it means limit/file-size mismatch.
When it happens
Trigger: A data file in the stream offset range contains more rows than the configured maxRecordsPerMicroBatch; detected in latestOffset while computing the limited batch offset.
Common situations: Streaming reads over tables written with very large compaction outputs or unpartitioned bulk backfills; too-low maxRecordsPerMicroBatch setting relative to file sizes.
Understand the failure class
Background: "value must be between 0 and 1" / "out of range" / "must not be negative" errors: fixing range-validation failures across open-source libraries — this error's family across 42 libraries.
Related errors
- File at offset contains records, exceeding…
- File at offset contains records, exceeding…
- File at offset contains records, exceeding…
- File contains records, exceeding maxRecordsPerMicroBatch…
- File contains records, exceeding maxRecordsPerMicroBatch…
AI-assisted analysis of apache/iceberg@86d9c8fc54 (2026-09-12).
Data as JSON: /api/errors/06e4dd2edb50f161.
Report an issue: GitHub.
Appendix: source
Thrown at spark/v4.0/spark/src/main/java/org/apache/iceberg/spark/source/AsyncSparkMicroBatchPlanner.java:328
if (filesSeen == 0) {
return null;
}
LOG.debug(
"latestOffset hit file limit at {}, rows: {}, files: {}",
elem.first(),
rowsSeen,
filesSeen);
return elem.first();
}
// Soft limit on rows - include file FIRST, then check
rowsSeen += fileRows;
filesSeen += 1;
// Check if we've hit the row limit after including this file
if (rowsSeen >= unpackedLimits.getMaxRows()) {
if (filesSeen == 1 && rowsSeen > unpackedLimits.getMaxRows()) {
LOG.warn(
"File {} at offset {} contains {} records, exceeding maxRecordsPerMicroBatch limit of {}. "
+ "This file will be processed entirely to guarantee forward progress. "
+ "Consider increasing the limit or writing smaller files to avoid unexpected memory usage.",
elem.second().file().location(),
elem.first(),
fileRows,
unpackedLimits.getMaxRows());
}
// Return the offset of the NEXT element (or synthesize tail+1)
if (i + 1 < queueSnapshot.size()) {
LOG.debug(
"latestOffset hit row limit at {}, rows: {}, files: {}",
queueSnapshot.get(i + 1).first(),
rowsSeen,
filesSeen);
return queueSnapshot.get(i + 1).first();
} else {
// This is the last element - return tail+1View on GitHub (pinned to 86d9c8fc54)