What is rate limiting?
A rate limit is software technique used in computing to control the rate of traffic sent or received by a network, system, or online service. It involves setting limits on the number of requests or actions that can be performed within a specific time period.
Where is rate limitation used?
APIs: Usually API impose rate limits to restrict the number of requests a client can make within a given time frame. This helps prevent abuse, ensures fair usage, and maintains system performance.
Web servers: Web servers can implement rate limiting to prevent Denial of Service (DoS) attacks, where attackers flood the server with excessive requests, causing it to become unresponsive.
Authentication systems: Rate limiting can be used to control the number of login attempts per user, preventing brute-force hacking attacks on user accounts.
Network traffic management: Rate limiting can be applied to network traffic to ensure that certain types of traffic (e.g., video streaming, file downloads) do not consume all available bandwidth, leaving room for other important traffic.
Why is rate limiting used for?
For stability, security, and efficiency of systems and services in various digital infrastructures, including networking, software development, and web services.
Specific reasons include:
Resource Allocation: rate limiting ensures fair distribution of resources among users or processes by preventing any single user or process from monopolizing resources.
Protection Against Abuse: usage limits helps prevent abuse or misuse of resources, such as preventing spamming, hackers attacks like DDoS, or excessive data consumption.
Stability and Reliability: By preventing sudden spikes in traffic or requests, rate limiting can stabilize systems and improve overall reliability.
Cost & Power Management: It can help control costs associated with resources usage, especially in cloud computing environments where resources may have associated costs and power consumption.
Compliance: Some businesses follow compliance guidances expressed in service level agreements (SLAs), regulatory requirements, or usage policies that consist usage limits.
Optimization: For system performance by preventing overload situations and reducing latency and allowing resources to be used more efficiently.
What means rate limit exceeded?
Exceeding the limit typically refers to a situation where a system or service has enforced a maximum threshold on the rate of requests or actions that can be performed within a specific time frame, and the user or client has exceeded usage cap.
For example, many APIs (Application Programming Interfaces) impose rate limits to prevent abuse or overload on their servers. When a client makes requests to such an API at a rate that surpasses the allowed limit, the API may respond with a "rate limit exceeded" error message, indicating that the client needs to slow down or wait before making additional requests.
What happens when exceeding a rate limit?
When exceeding a rate limit, several things might happen depending on the system or service being used:
Error Response: The system may return an error message indicating that the rate limit has been exceeded. This could be accompanied by a specific HTTP status code (e.g., 429 Too Many Requests) to inform the client that they need to slow down.
Notification: Some systems may send notifications (like web push notification) to the user or client informing them that they have exceeded the limits and providing guidance on how to avoid future violations.
Temporary Blocking: The system might temporarily block further requests from the user or client that exceeded the rate limit. This block could last for a predefined period before the client is allowed to make requests again.
Throttling: Instead of completely blocking requests, the system might throttle or slow down the rate at which requests are processed from the user or client that exceeded the limit. This ensures that the system remains operational but may result in slower response times for the client.
Account Suspension: In severe cases of abuse or repeated violations of rate limits, the user's account or access to the service might be temporarily or permanently suspended.
Overall, the specific consequences of exceeding a rate limit depend on the policies and mechanisms implemented by the system or service provider.
Other names for rate limit:
Rate cap
Quota
Bandwidth limit
Usage cap
Traffic control
Rate ceiling
Throughput restriction
