@Test
public void shouldNotEvictAccessedBucket() throws Exception {
FakeTimeService time = new FakeTimeService(0);
ThrottlingFilter filter =
new ThrottlingFilter(time, 2, duration("3 seconds"), DEFAULT_PARTITION_EXPR);
Context context = mock(Context.class);
Request request;
// Here we access the same bucket every 2 seconds : enough time to add a refilled token but not
// enough for the
// bucket to be evicted.
Handler handler1 = mock(Handler.class, "handler1");
request = new Request();
filter.filter(context, request, handler1);
verify(handler1).handle(context, request);
time.advance(duration("2 seconds"));
Handler handler2 = mock(Handler.class, "handler2");
request = new Request();
filter.filter(context, request, handler2);
verify(handler2).handle(context, request);
assertThat(filter.getBucketsStats().evictionCount()).isEqualTo(0);
time.advance(duration("2 seconds"));
Handler handler3 = mock(Handler.class, "handler3");
request = new Request();
filter.filter(context, request, handler3);
verify(handler3).handle(context, request);
assertThat(filter.getBucketsStats().evictionCount()).isEqualTo(0);
}
@Test
public void shouldThrottleRequests() throws Exception {
FakeTimeService time = new FakeTimeService(0);
ThrottlingFilter filter =
new ThrottlingFilter(time, 1, duration("3 seconds"), DEFAULT_PARTITION_EXPR);
// This one has to call the handler as there are enough tokens in the bucket.
Handler handler1 = mock(Handler.class, "handler1");
filter.filter(mock(Context.class), new Request(), handler1);
verify(handler1).handle(any(Context.class), any(Request.class));
time.advance(duration("2 seconds"));
// This one does not have to be called as there is no token anymore in the bucket.
Handler handler2 = mock(Handler.class, "handler2");
Promise<Response, NeverThrowsException> promise2 =
filter.filter(mock(Context.class), new Request(), handler2);
verifyZeroInteractions(handler2);
assertThat(promise2.get().getStatus()).isEqualTo(Status.TOO_MANY_REQUESTS);
time.advance(duration("4 seconds"));
// This one has to call the handler as the bucket has been refilled.
Handler handler3 = mock(Handler.class, "handler3");
filter.filter(mock(Context.class), new Request(), handler3);
verify(handler3).handle(any(Context.class), any(Request.class));
}
@Test
public void shouldThrottleConcurrentRequests() throws Exception {
CountDownLatch latch1 = new CountDownLatch(1);
CountDownLatch latch2 = new CountDownLatch(1);
FakeTimeService time = new FakeTimeService(0);
final ThrottlingFilter filter =
new ThrottlingFilter(time, 1, duration("3 seconds"), DEFAULT_PARTITION_EXPR);
// This one has to be called as there are enough tokens in the bucket.
final Handler handler1 = new LatchHandler(latch1, latch2);
Runnable r =
new Runnable() {
@Override
public void run() {
filter.filter(mock(Context.class), new Request(), handler1);
}
};
Thread t1 = new Thread(r);
t1.setName("Filter for request #1");
t1.start();
latch2.await();
time.advance(duration("2 seconds"));
try {
// This one does not have to be called as there no token anymore in the bucket.
Handler handler2 = mock(Handler.class, "handler2");
Promise<Response, NeverThrowsException> promise2 =
filter.filter(mock(Context.class), new Request(), handler2);
verifyZeroInteractions(handler2);
Response response = promise2.get(20, TimeUnit.SECONDS);
assertThat(response.getStatus()).isEqualTo(Status.TOO_MANY_REQUESTS);
assertThat(response.getHeaders().getFirst("Retry-After")).isEqualTo("1");
} finally {
latch1.countDown();
t1.join();
}
}
@Test
public void shouldEvictObsoleteBucket() throws Exception {
FakeTimeService time = new FakeTimeService(0);
ThrottlingFilter filter =
new ThrottlingFilter(time, 1, duration("3 seconds"), DEFAULT_PARTITION_EXPR);
Context context = mock(Context.class);
// Call the filter in order to trigger the bucket creation
Handler handler1 = mock(Handler.class, "handler1");
filter.filter(context, new Request(), handler1);
verify(handler1).handle(any(Exchange.class), any(Request.class));
time.advance(duration("4 seconds"));
// After 3 seconds, the previously bucket should be discarded, force a new call so that the
// cache will clean its
// internal structure
Handler handler2 = mock(Handler.class, "handler2");
filter.filter(context, new Request(), handler2);
verify(handler2).handle(any(Exchange.class), any(Request.class));
assertThat(filter.getBucketsStats().evictionCount()).isEqualTo(1);
}