To prevent abuse, you should consider adding rate limiting to your APIs. For example, you may limit the API usage
To prevent abuse, you should consider adding *rate limiting* to your APIs. For example, you may want to limit the API usage
of each user to be at most 100 API calls within a period of 10 minutes. If too many requests are received from a user
within the period of the time, a response with status code 429 (meaning Too Many Requests) should be returned.
within the stated period of the time, a response with status code 429 (meaning "Too Many Requests") should be returned.
To enable rate limiting, the [[yii\web\User::identityClass|user identity class]] should implement [[yii\filters\RateLimitInterface]].
This interface requires implementation of the following three methods:
This interface requires implementation of three methods:
*`getRateLimit()`: returns the maximum number of allowed requests and the time period, e.g., `[100, 600]` means
at most 100 API calls within 600 seconds.
*`getRateLimit()`: returns the maximum number of allowed requests and the time period (e.g., `[100, 600]` means there can be at most 100 API calls within 600 seconds).
*`loadAllowance()`: returns the number of remaining requests allowed and the corresponding UNIX timestamp
when the rate limit is checked last time.
*`saveAllowance()`: saves the number of remaining requests allowed and the current UNIX timestamp.
when the rate limit was last checked.
*`saveAllowance()`: saves both the number of remaining requests allowed and the current UNIX timestamp.
You may use two columns in the user table to record the allowance and timestamp information.
And `loadAllowance()` and `saveAllowance()` can then be implementation by reading and saving the values
You may want to use two columns in the user table to record the allowance and timestamp information. With those defined, then `loadAllowance()` and `saveAllowance()` can be implemented to read and save the values
of the two columns corresponding to the current authenticated user. To improve performance, you may also
consider storing these information in cache or some NoSQL storage.
consider storing these pieces of information in a cache or NoSQL storage.
Once the identity class implements the required interface, Yii will automatically use [[yii\filters\RateLimiter]]
configured as an action filter for [[yii\rest\Controller]] to perform rate limiting check. The rate limiter
will thrown a [[yii\web\TooManyRequestsHttpException]] if rate limit is exceeded. You may configure the rate limiter
as follows in your REST controller classes,
will throw a [[yii\web\TooManyRequestsHttpException]] when the rate limit is exceeded.
You may configure the rate limiter
as follows in your REST controller classes:
```php
publicfunctionbehaviors()
...
...
@@ -36,9 +36,9 @@ public function behaviors()
When rate limiting is enabled, by default every response will be sent with the following HTTP headers containing
the current rate limiting information:
*`X-Rate-Limit-Limit`: The maximum number of requests allowed with a time period;
*`X-Rate-Limit-Remaining`: The number of remaining requests in the current time period;
*`X-Rate-Limit-Reset`: The number of seconds to wait in order to get the maximum number of allowed requests.
*`X-Rate-Limit-Limit`, the maximum number of requests allowed with a time period
*`X-Rate-Limit-Remaining`, the number of remaining requests in the current time period
*`X-Rate-Limit-Reset`, the number of seconds to wait in order to get the maximum number of allowed requests
You may disable these headers by configuring [[yii\filters\RateLimiter::enableRateLimitHeaders]] to be false,
