Restrictions on request data rate
- Last UpdatedMay 29, 2026
- 1 minute read
- PI System
- PI Web API 2023 SP2
- Developer
You can limit the rate at which clients request data by setting rate limit parameters in the Configuration database.
The following configuration items are available in PI Web API:
RateLimitMaxRequests
The maximum number of requests per client (identified by IP address) over a specified duration of time.
Add or set the configuration item in PI System Explorer:
|
Field |
Description or value |
|---|---|
|
Value Type |
Int32 |
|
Value |
Enter a numeric string that represents the maximum number of requests per client. Default: 1,000 |
RateLimitDuration
The period of time, in seconds, that the client is limited to a specific number of requests.
Add or set the configuration item in PI System Explorer:
|
Field |
Description or value |
|---|---|
|
Value Type |
Int32 |
|
Value |
Enter a numeric string that represents the number of seconds per client. Default: 1 |
The rate limit per client IP address is calculated with the formula:
Rate limit per second per IP = RateLimitMaxRequests / RateLimitDuration
With default parameter values, this limit resets every single second, meaning that a maximum of 1000 requests can be made per second.
If the rate limit is reached or exceeded, a response is returned with HTTP status 429 (Too Many Requests). The response status code contains the following error message: "Rate limit was reached".