What the data for this category looks like
Ledger data for rail transit equipment comes from on-board operating sensors, offline maintenance systems, and spare parts management modules. The update cadence is real-time collection of operating parameters, daily synchronization of maintenance records, and monthly updates of spare parts inventory. Each individual ledger document includes fields such as unique device ID, model specification, cumulative operating hours, last maintenance date, and spare parts replacement details. Units include operating hours, maintenance counts, spare part dimensions in millimeters, and lubricant volume in liters. Some documents include high-resolution maintenance photos and operating log attachments.
What constraints these characteristics impose during deployment and upgrade
Data sources for rail transit equipment ledgers are scattered, and update frequencies vary. During deployment, support for multiple data source connections and concurrent writes is required, so database connection pool configuration must adapt to high-concurrency scenarios. During upgrades, real-time data synchronization cannot be interrupted, so a rolling upgrade strategy must be used to avoid loss of operating parameters due to service restarts. The mixed storage of structured fields and attachments requires the knowledge base to support indexing for both relational and unstructured data. Upgrades must be compatible with old data formats to avoid migration failures. Additionally, ledger data fields and units follow industry-specific rules. During deployment, the knowledge base’s field mapping rules must align with industry standards to avoid data parsing errors.
Configuration Settings
Reference only; verify against the target FastGPT release and deployment documentation.
| Configuration Item | Recommended Setting | Rationale |
|---|---|---|
DB_MAX_LINK | 150–200 connections | Rail transit equipment ledger data has multiple sources and high update frequencies, requiring support for concurrent connections and batch writes |
MONGODB_URI | mongodb://mongodb:27017/fastgpt | Stores maintenance report attachments, historical conversation records, and unstructured ledger fragments |
REDIS_URL | redis://redis:6379/0 | Caches frequently accessed device ledger snapshots to reduce query pressure on relational databases |
FE_DOMAIN | https://your-gpt-domain.com | Used to configure the access address of the front-end embedded page, adapting to the domain name rules of existing systems |
FILE_TOKEN_KEY | 32-bit random string, calibrated via actual testing | Protects download permissions for ledger attachments to prevent unauthorized access |
STORAGE_S3_ENDPOINT | http://minio:9000 | Stores monthly ledger summary reports exported in bulk, compatible with local object storage services |
Three Common Mistakes
- Symptom:
connection refusederror appears when starting the container, unable to connect to the database. Cause: The address specified inMONGODB_URIorREDIS_URLdoes not correctly point to the locally deployed service container, or the corresponding ports are not open in the firewall. - Symptom: Historical conversation records and device ledger cache are not cleared after executing Docker Compose restart. Cause: No persistent volume configured for the
REDIS_URLcorresponding service, so session cache data is not cleared when the container is deleted. - Symptom: Generated ledger report attachments cannot be downloaded normally. Cause: Incorrect
FILE_TOKEN_KEYconfiguration, leading to failed attachment download permission verification and inability to generate valid access links.
How to Confirm the Configuration is Correct
- Execute the
docker pscommand to confirm that the MongoDB, Redis, front-end service, and API service containers are all in a running state. - Call the ledger synchronization interface, pass a simulated rail transit equipment device ID, and check that the returned fields include required items such as device model and operating hours, with no null values.
- Upload a rail transit equipment maintenance report PDF, trigger the ledger summary task, confirm that the task status shows completed, and the generated report contains correct summary data.
- Access the address configured in
FE_DOMAIN, confirm that the front-end page loads normally, and can call the API to retrieve device ledger data.
The values provided 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.