Baoyuantop commented on issue #12577: URL: https://github.com/apache/apisix/issues/12577#issuecomment-3244123921
Hi @avaldor-dw, I followed the steps you provided to reproduce the problem locally, and the results were the same as yours. However, this is not a bug in APISIX, but the expected behavior. The limit-req plugin uses the [leaky bucket](https://en.wikipedia.org/wiki/Leaky_bucket) algorithm to rate limit the number of the requests and allow for throttling. You can think of network requests or data packets as filling a bucket with water. There is a small hole at the bottom of the bucket, and the water flows out at a fixed rate. The bucket can only hold a limited amount of water (requests). If the capacity is exceeded, it overflows (requests are discarded). Regardless of how quickly water is added to the top layer, the rate of water leakage from the bottom of the bucket remains constant (the system processing rate is fixed). When the inflow of requests exceeds the bucket capacity plus the outflow rate, the excess requests are discarded. Based on your configuration, the rate is set to 5 and the burst is set to 0. This means that you expect a leak rate of 5 requests per second, or one request every 0.2 seconds. However, the bucket size is 0, so any request that exceeds the 0.2-second interval will be dropped. The first request took only 0.085 seconds to process (you can see this by printing the timestamp). This is before the 0.2 second limit, and your bucket size is set to 0, so all other requests are discarded. The requests that apisix returns a 429 error take an average of 0.015 seconds each. If your expected behavior is to pass 5 requests per second, I think the [limit-count](https://docs.api7.ai/hub/limit-count/) plugin is more suitable for your needs. You can refer to the configuration: ``` "plugins": { "limit-count": { "count": 5, "time_window": 1, "rejected_code": 429, "rejected_msg": "Later!!!", "key": "consumer_name" } }, ``` -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: notifications-unsubscr...@apisix.apache.org For queries about this service, please contact Infrastructure at: us...@infra.apache.org
