What the data for this category looks like
Coal chemical industry yield and daily market quote data is primarily sourced from domestic bulk commodity spot monitoring platforms and public exchange data. It covers mainstream coal chemical products including methanol, polypropylene, and similar categories. Data updates run from 16:00 to 18:00 daily for same-day full category quotes. Weekly cumulative yield statistics are added each week. Each individual data entry uses a standard JSON structure, containing fields such as product identifier, daily closing price, price change rate, daily trading volume, and others. The unit for closing price is yuan per ton, the unit for price change rate is percentage, and the unit for trading volume is tons or trading lots.
Constraints Imposed on HTTP Interfaces and External Systems
The multi-source data nature of coal chemical product data requires interfaces to support concurrent request control, to avoid triggering data source rate limiting rules. Fixed update schedules require scheduled task trigger windows to align with data source update times. Misalignment may result in pulling unupdated empty data or outdated data. Differences across multiple field units require unified mapping in interface responses, to avoid unit confusion during external system processing. Category-specific identifier fields require precise filtering rules for interfaces, to prevent unrelated data from other coal categories from being included. Additionally, the daily update frequency requires interface cache durations to match the daily update cycle, to reduce resource consumption from repeated requests.
Configuration Settings
| Configuration Item | Recommended Value | Rationale |
|---|---|---|
external_api_request_timeout | 30 seconds | Covers normal response durations for most coal chemical data sources, prevents workflow blocking |
api_data_filter_rule | product_category = "coal_chemical" | Precise filtering of non-coal chemical category quote data, ensures pulled content matches the use case |
scheduled_task_cron | 0 17 * * * | Aligns with the daily 16:00-18:00 update window for most data sources, triggers data pulling after updates complete |
response_parse_field_mapping | {"close_price": "yuan_per_ton", "change_rate": "percent"} | Maps native interface fields to standard formats and units recognizable by external systems |
api_cache_ttl | 86400 seconds | Matches the daily update cycle for daily reports, reduces resource usage from repeated requests |
api_request_rate_limit | 10 requests per minute | Adapts to rate limiting rules for most coal chemical data sources, avoids interface blocking |
The parameter values provided on this page are common starting points for configuration. Actual values are affected by material form, data volume and business rules. Specific issues require specific analysis, and it is recommended to test on your own samples before finalizing.
Three Common Configuration Errors
- Phenomenon: Calling the external interface returns a
401 Unauthorizedstatus code, and logs show key limit exceeded or expired. Cause: Theapi_key_expire_durationandapi_request_rate_limitparameters are not configured, leading to insufficient key validity period or request frequency exceeding data source limits. - Phenomenon: Pulled market quote data includes information from non-coal chemical products such as coking coal and thermal coal. Cause: The
api_data_filter_ruleparameter is not configured, or the filtering rule does not accurately match the coal chemical product identifier, leading to unrelated data being pulled. - Phenomenon: The external system receives empty interface response fields or abnormal format. Cause: The
response_parse_field_mappingparameter is not configured, making it impossible to correctly parse the native fields returned by the interface, leading to the external system being unable to read valid content.
How to Confirm Correct Configuration
- Manually trigger an external interface request, check that the returned JSON data only includes quote fields for coal chemical products, with no data from other unrelated categories.
- View scheduled task execution logs, confirm that the task triggers at the specified daily time period, and that no timeout or rate limiting errors occur in requests.
- Connect to the external system's test environment, verify that the pulled data fields fully match the expected format and units of the external system.
- Check the key and rate limiting configuration items, confirm that the key validity period and request frequency comply with the data source access rules, and no abnormal prompts appear.
Question material comes from public community discussions. Configuration values are common starting points and should be measured against your own samples. Verified on 2026-09-14.