What this type of data looks like
Ledger data for power generation groups comes from electronic documents exported from on-site station operation logs, fuel dispatch reports, and maintenance ledger systems. The update cadence is shift-based reporting, daily summary, and monthly archiving. Most documents are fixed-format multi-page PDFs, containing fields such as unit number, operation parameters, consumable usage, and maintenance milestones. Common units include megawatt-hours, tons, hours, ten thousand kilowatts, and others. Some documents have cross-page repeating headers and nested table structures.
What constraints do these characteristics impose on document parsing and chunking?
Fixed-format cross-page headers cause standard parsing tools to lose the association between headers and corresponding data. Context-preserving parsing logic is required. Nested table structures require that chunks do not split complete cross-page data items, as this would damage business semantic integrity. Large volumes of batch-reported documents require appropriate upload and parsing timeout settings to avoid mid-parsing interruptions. Fields include professional units, so chunking must retain the binding between fields and units to avoid semantic breaks. Frequently updated documents require reusable parsing configuration to reduce the cost of repeated adjustments.
How to set configurations
Reference only; verify against the target FastGPT release and deployment documentation.
| Configuration Item | Recommended Setting | Rationale |
|---|---|---|
chunkSize | 800–1200 characters | The length of single data items in power generation group ledgers is mostly 600-1000 characters. This range can fully wrap a single set of operation parameters and corresponding descriptions, avoiding semantic splitting |
chunkSplitter | Line break + fixed header keyword matching | Ledger documents have fixed headers and segmented line breaks. This rule prevents merging unrelated data across segments while retaining header associations |
customPdfParse | Enable cross-page header repair mode | Most power generation group ledgers have cross-page repeating headers. Enabling this mode automatically associates cross-page headers with data, avoiding field misalignment |
UPLOAD_FILE_MAX_SIZE | 1000 MB | Adapts to the volume of multi-page ledger PDFs submitted in batches, preventing failure of single large file uploads |
PARSE_FILE_TIMEOUT_SECONDS | 600 seconds | Large ledger PDF parsing requires a long processing time. This duration covers most single-file parsing workflows, avoiding mid-process timeout errors |
chunkSettingMode | Manual configuration | Adapts to the fixed format characteristics of ledgers. Manual configuration allows precise matching of document structures, avoiding unreasonable splitting from automatic chunking |
Three common configuration errors
- Phenomenon: An error is triggered after uploading a 3MB ledger PDF, and the interface returns
{"detail":"Error message"}. Cause: TheUPLOAD_FILE_MAX_SIZEorPARSE_FILE_TIMEOUT_SECONDSparameters were not adjusted, resulting in large files exceeding default limits or insufficient parsing duration. - Phenomenon: A custom delimiter is set to line breaks, but the chunking result still merges multiple paragraphs or splits a single complete data item. Cause: The
chunkSplitterwas not configured with the keyword rules matching the ledger headers. Using only line breaks cannot distinguish ledger content from different business sections. - Phenomenon: An error occurs when processing PDFs after deploying Marker, and parsed text blocks cannot be generated. Cause: The associated parameters for
customPdfParsewere not configured correctly, or environment variables did not match the cross-page table structure of power generation group ledgers.
How to confirm the configuration is correct
- Upload a single standard ledger PDF, check if the parsed text blocks retain the association between headers and corresponding data, with no field misalignment.
- Adjust the
chunkSizeparameter, then batch upload multiple ledger documents of different volumes, confirm there are no upload or parsing timeout errors. - Manually modify the chunking rules, compare chunking results under different configurations, confirm that complete business data items are not split during chunking.
- View parsing logs, confirm that the cross-page header repair function has been triggered normally, with no missing cross-page data associations.
The values given are common starting points and should be measured against the reader's own samples.
Question material comes from public community discussions. Configuration values are common starting points and should be measured against your own samples. Verified on 2026-09-28.