What the data for this category looks like
IT service desk data is sourced from ticket records, operation and maintenance logs, archived employee help request documents, and official software operation manuals from the enterprise internal IT service management system. The update schedule follows real-time synchronization of newly submitted help tickets, monthly updates of archived operation and maintenance logs, and quarterly synchronization of documents updated with new software versions. The document structure includes structured fields such as ticket number, problem category, and processing duration, as well as unstructured text such as problem details and repair steps. Some documents include attribute fields like device model and software version, and there is no unified fixed format template.
What constraints these characteristics impose on the knowledge base retrieval and recall link
The real-time data requirements for IT service desks require the retrieval link to support incremental synchronization of newly generated tickets and operation and maintenance records, to avoid retrieval delays caused by full index reconstruction. The mixed structured and unstructured document structure requires retrieval to cover both keyword matching and semantic recall, while supporting filtering of the recall scope using attribute fields such as device model and software version. Long-text repair step documents need to use reasonable chunking rules to avoid recall failure caused by semantic segmentation. High-frequency repeated employee help request scenarios require optimizing recall deduplication and sorting logic to reduce interference from redundant results.
How to set the configurations
| Configuration Item | Recommended Value Range | Rationale |
|---|---|---|
similarity | 0.75–0.85 | Matches the common problem similarity range for IT service desks, balancing recall coverage and precision |
limit | Top 8–12 entries | Covers the 3-5 common similar problem scenarios for employees, retaining sufficient reference samples |
searchMode | hybrid | Adapts to the mixed structured and unstructured document structure, triggering both keyword and semantic retrieval |
usingReRank | Enabled | Re-ranks recall results by semantic relevance, optimizing the sorting logic for long-text documents |
datasetSearchUsingExtensionQuery | Enabled | Automatically expands query terms for vague IT help requests from employees, improving recall coverage |
collectionIds | Bind to the IT service desk-specific dataset | Isolates business data to avoid retrieving non-IT service documents |
Three common configuration mistakes
- Symptom: The re-ranking model passes deployment testing, but the
usingReRankfield returned by each retrieval is false, and re-ranking results do not take effect. Cause: The re-ranking model is not correctly associated with the current IT service desk dataset, or the retrieval link does not call the deployed re-ranking service. - Symptom: The retrieval link returns an error for exceeding the block count limit, or recall results have semantic breaks. Cause: Chunking rules are not adjusted to adapt to the long document characteristics of IT service desks, resulting in a single document being split into more than 3000 chunks, which exceeds the processing limit of the retrieval link.
- Symptom: The tool call link cannot select the specified IT service desk knowledge base. Cause: The knowledge base is not bound to the current IT service desk service link, or the
collectionIdsparameter is not correctly configured as the target dataset ID.
How to confirm the configuration is complete
- Enter the retrieval debugging page of FastGPT v4.17.0, and check whether currently configured parameters such as
similarityandlimitmatch the set values. - Submit a typical IT service desk help request question, and verify whether the number and relevance of recall results meet the expected retrieval scope.
- After enabling the re-ranking function, compare the initial sorting of recall results with the sorted results after re-ranking to confirm that the re-ranking logic has taken effect.
- In the tool call configuration interface, check whether the bound IT service desk-specific dataset is included in the selectable knowledge base list.
The values provided are common starting points and should be measured against samples from the target deployment.
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.