Rate Limiter Java Library
A Java library for rate limiting, assembled using extensible storage and application framework adaptors. The library's interfaces support thread-safe sync, async, and reactive usage patterns.
Modules
RateLimiterJava provides the following stable pluggable modules
- Fixed Window rate limiter
- Sliding Window rate limiter
Features
Configuration can be made to store the user data in redis using these modules. Lua scripts is used in following cases to reduce redis calls
- Sliding Window rate limiter
- In case user data is handled using this library
Installation
Add the dependency to your pom.xml file
<dependency>
<groupId>io.github.kidminks</groupId>
<artifactId>rate-limiter-java</artifactId>
<version>0.0.1</version>
</dependency>Then run from the root dir of the project:
mvn install
Prerequisite
- jedis
- javax.validation
- guava
- lombok
Examples
Example Rate Limiter Service
Create a service RateLimiterService which will handle the library linking
package com.example.demo;
import io.github.kidminks.rate.limiter.core.abst.AbstractRateLimiter;
import io.github.kidminks.rate.limiter.core.factory.RateLimiterFactory;
import io.github.kidminks.rate.limiter.model.dto.Configuration;
import io.github.kidminks.rate.limiter.model.dto.LimitDetails;
import io.github.kidminks.rate.limiter.model.enums.RateLimiterType;
import org.springframework.stereotype.Component;
import org.springframework.stereotype.Service;
@Component
@Service
public class RateLimiterService {
private AbstractRateLimiter slidingWindowRateLimiter;
private AbstractRateLimiter fixedWindowRateLimiter;
private void initSlidingWindowRateLimiter() {
Configuration configuration = Configuration.builder()
.redisHost("localhost")
.redisPort(6379)
.redisDb(1)
.maxTotal(10)
.maxIdle(1)
.useLuaScript(true)
.build();
this.slidingWindowRateLimiter = RateLimiterFactory.getRateLimiter(configuration, RateLimiterType.SLIDING_WINDOW);
}
private void initFixedWindowRateLimiter() {
Configuration configuration = Configuration.builder()
.redisHost("localhost")
.redisPort(6379)
.redisDb(1)
.maxTotal(10)
.maxIdle(1)
.useLuaScript(false)
.build();
this.fixedWindowRateLimiter = RateLimiterFactory.getRateLimiter(configuration, RateLimiterType.FIXED_WINDOW);
}
public RateLimiterService() {
initSlidingWindowRateLimiter();
initFixedWindowRateLimiter();
}
public Boolean checkSlidingWindowLimit(String key) {
return slidingWindowRateLimiter.check(new LimitDetails(key, 100L, 3600000L));
}
public Boolean checkFixedWindowLimit(String key) {
return fixedWindowRateLimiter.check(new LimitDetails(key, 100L, 3600000L));
}
}Sliding Window
Checking limits left using sliding rate limiter api. These checks using lua scripts. Old request data are deleted with every request
@RestController
@RequestMapping("/")
@Slf4j
public class RateLimiterTestController {
@Autowired
private RateLimiterService rateLimiterService;
@GetMapping("/sliding-window")
public void slidingWindowTest(@RequestHeader("X-AUTH-TOKEN") String token) {
if(rateLimiterService.checkSlidingWindowLimit(token)) {
log.info("limit available");
return;
}
log.info("limit not available");
}
}Fixed Window
increment function of redis is used to increase the key count. Every time a new key is created expiry is set and that key is deleted after the end.
@RestController
@RequestMapping("/")
@Slf4j
public class RateLimiterTestController {
@Autowired
private RateLimiterService rateLimiterService;
@GetMapping("/fixed-window")
public void fixedWindowTest(@RequestHeader("X-AUTH-TOKEN") String token) {
if(rateLimiterService.checkFixedWindowLimit(token)) {
log.info("limit available");
return;
}
log.info("limit not available");
}
}Roadmap
| Feature | Status |
|---|---|
| Sliding Window rate limiter | Released |
| Fixed Window rate limiter | Released |
| Store user data | Ongoing |
