/**
* When volume of reporting during a statistical window is lower than a defined threshold the
* circuit will not trip regardless of whatever statistics are calculated.
*/
@Test
public void testLowVolumeDoesNotTripCircuit() {
String key = "cmd-I";
try {
int sleepWindow = 200;
int lowVolume = 5;
HystrixCommand<Boolean> cmd1 = new FailureCommand(key, 60, sleepWindow, lowVolume);
HystrixCircuitBreaker cb = cmd1.circuitBreaker;
// this should start as allowing requests
assertTrue(cb.allowRequest());
assertFalse(cb.isOpen());
cmd1.execute();
HystrixCommand<Boolean> cmd2 = new FailureCommand(key, 1, sleepWindow, lowVolume);
cmd2.execute();
HystrixCommand<Boolean> cmd3 = new FailureCommand(key, 1, sleepWindow, lowVolume);
cmd3.execute();
HystrixCommand<Boolean> cmd4 = new FailureCommand(key, 1, sleepWindow, lowVolume);
cmd4.execute();
// even though it has all failed we won't trip the circuit because the volume is low
Thread.sleep(100);
assertTrue(cb.allowRequest());
assertFalse(cb.isOpen());
} catch (Exception e) {
e.printStackTrace();
fail("Error occurred: " + e.getMessage());
}
}
/** Test that if all 'marks' are timeouts that it will trip the circuit. */
@Test
public void testTripCircuitOnTimeouts() {
String key = "cmd-D";
try {
HystrixCommand<Boolean> cmd1 = new TimeoutCommand(key);
HystrixCircuitBreaker cb = cmd1.circuitBreaker;
// this should start as allowing requests
assertTrue(cb.allowRequest());
assertFalse(cb.isOpen());
// success with high latency
cmd1.execute();
HystrixCommand<Boolean> cmd2 = new TimeoutCommand(key);
cmd2.execute();
HystrixCommand<Boolean> cmd3 = new TimeoutCommand(key);
cmd3.execute();
HystrixCommand<Boolean> cmd4 = new TimeoutCommand(key);
cmd4.execute();
// everything has been a timeout so we should not allow any requests
Thread.sleep(100);
assertFalse(cb.allowRequest());
assertTrue(cb.isOpen());
} catch (Exception e) {
e.printStackTrace();
fail("Error occurred: " + e.getMessage());
}
}
/**
* Test that an open circuit is closed after 1 success. This also ensures that the rolling window
* (containing failures) is cleared after the sleep window Otherwise, the next bucket roll would
* produce another signal to fail unless it is explicitly cleared (via {@link
* HystrixCommandMetrics#resetStream()}.
*/
@Test
public void testCircuitClosedAfterSuccess() {
String key = "cmd-G";
try {
int sleepWindow = 20;
HystrixCommand<Boolean> cmd1 = new FailureCommand(key, 1, sleepWindow);
HystrixCircuitBreaker cb = cmd1.circuitBreaker;
// this should start as allowing requests
assertTrue(cb.allowRequest());
assertFalse(cb.isOpen());
cmd1.execute();
HystrixCommand<Boolean> cmd2 = new FailureCommand(key, 1, sleepWindow);
cmd2.execute();
HystrixCommand<Boolean> cmd3 = new FailureCommand(key, 1, sleepWindow);
cmd3.execute();
HystrixCommand<Boolean> cmd4 = new TimeoutCommand(key, sleepWindow);
cmd4.execute();
// everything has failed in the test window so we should return false now
Thread.sleep(100);
System.out.println(
"ReqLog : " + HystrixRequestLog.getCurrentRequest().getExecutedCommandsAsString());
System.out.println("CircuitBreaker state 1 : " + cmd1.getMetrics().getHealthCounts());
assertFalse(cb.allowRequest());
assertTrue(cb.isOpen());
// wait for sleepWindow to pass
Thread.sleep(sleepWindow + 50);
// but the circuit should still be open
assertTrue(cb.isOpen());
// we should now allow 1 request, and upon success, should cause the circuit to be closed
HystrixCommand<Boolean> cmd5 = new SuccessCommand(key, 60, sleepWindow);
Observable<Boolean> asyncResult = cmd5.observe();
// and further requests are still blocked while the singleTest command is in flight
assertFalse(cb.allowRequest());
asyncResult.toBlocking().single();
// all requests should be open again
System.out.println("CircuitBreaker state 2 : " + cmd1.getMetrics().getHealthCounts());
assertTrue(cb.allowRequest());
assertTrue(cb.allowRequest());
assertTrue(cb.allowRequest());
// and the circuit should be closed again
assertFalse(cb.isOpen());
} catch (Exception e) {
e.printStackTrace();
fail("Error occurred: " + e.getMessage());
}
}
/**
* Test that on an open circuit that a single attempt will be allowed after a window of time to
* see if issues are resolved.
*/
@Test
public void testSingleTestOnOpenCircuitAfterTimeWindow() {
String key = "cmd-F";
try {
int sleepWindow = 200;
HystrixCommand<Boolean> cmd1 = new FailureCommand(key, 60);
HystrixCircuitBreaker cb = cmd1.circuitBreaker;
// this should start as allowing requests
assertTrue(cb.allowRequest());
assertFalse(cb.isOpen());
cmd1.execute();
HystrixCommand<Boolean> cmd2 = new FailureCommand(key, 1);
cmd2.execute();
HystrixCommand<Boolean> cmd3 = new FailureCommand(key, 1);
cmd3.execute();
HystrixCommand<Boolean> cmd4 = new FailureCommand(key, 1);
cmd4.execute();
// everything has failed in the test window so we should return false now
Thread.sleep(100);
assertFalse(cb.allowRequest());
assertTrue(cb.isOpen());
// wait for sleepWindow to pass
Thread.sleep(sleepWindow + 50);
// we should now allow 1 request
assertTrue(cb.allowRequest());
// but the circuit should still be open
assertTrue(cb.isOpen());
// and further requests are still blocked
assertFalse(cb.allowRequest());
} catch (Exception e) {
e.printStackTrace();
fail("Error occurred: " + e.getMessage());
}
}
/** Test that if the % of failures is higher than the threshold that the circuit trips. */
@Test
public void testCircuitDoesNotTripOnFailuresBelowThreshold() {
String key = "cmd-C";
try {
HystrixCommand<Boolean> cmd1 = new SuccessCommand(key, 60);
HystrixCircuitBreaker cb = cmd1.circuitBreaker;
// this should start as allowing requests
assertTrue(cb.allowRequest());
assertFalse(cb.isOpen());
// success with high latency
cmd1.execute();
HystrixCommand<Boolean> cmd2 = new SuccessCommand(key, 1);
cmd2.execute();
HystrixCommand<Boolean> cmd3 = new FailureCommand(key, 1);
cmd3.execute();
HystrixCommand<Boolean> cmd4 = new SuccessCommand(key, 1);
cmd4.execute();
HystrixCommand<Boolean> cmd5 = new SuccessCommand(key, 1);
cmd5.execute();
HystrixCommand<Boolean> cmd6 = new FailureCommand(key, 1);
cmd6.execute();
HystrixCommand<Boolean> cmd7 = new SuccessCommand(key, 1);
cmd7.execute();
HystrixCommand<Boolean> cmd8 = new FailureCommand(key, 1);
cmd8.execute();
// this should remain closed as the failure threshold is below the percentage limit
Thread.sleep(100);
System.out.println(
"ReqLog : " + HystrixRequestLog.getCurrentRequest().getExecutedCommandsAsString());
System.out.println("Current CircuitBreaker Status : " + cmd1.getMetrics().getHealthCounts());
assertTrue(cb.allowRequest());
assertFalse(cb.isOpen());
} catch (Exception e) {
e.printStackTrace();
fail("Error occurred: " + e.getMessage());
}
}
/**
* Test that if all 'marks' are successes during the test window that it does NOT trip the
* circuit. Test that if all 'marks' are failures during the test window that it trips the
* circuit.
*/
@Test
public void testTripCircuit() {
String key = "cmd-A";
try {
HystrixCommand<Boolean> cmd1 = new SuccessCommand(key, 1);
HystrixCommand<Boolean> cmd2 = new SuccessCommand(key, 1);
HystrixCommand<Boolean> cmd3 = new SuccessCommand(key, 1);
HystrixCommand<Boolean> cmd4 = new SuccessCommand(key, 1);
HystrixCircuitBreaker cb = cmd1.circuitBreaker;
cmd1.execute();
cmd2.execute();
cmd3.execute();
cmd4.execute();
// this should still allow requests as everything has been successful
Thread.sleep(100);
assertTrue(cb.allowRequest());
assertFalse(cb.isOpen());
// fail
HystrixCommand<Boolean> cmd5 = new FailureCommand(key, 1);
HystrixCommand<Boolean> cmd6 = new FailureCommand(key, 1);
HystrixCommand<Boolean> cmd7 = new FailureCommand(key, 1);
HystrixCommand<Boolean> cmd8 = new FailureCommand(key, 1);
cmd5.execute();
cmd6.execute();
cmd7.execute();
cmd8.execute();
// everything has failed in the test window so we should return false now
Thread.sleep(100);
assertFalse(cb.allowRequest());
assertTrue(cb.isOpen());
} catch (Exception e) {
e.printStackTrace();
fail("Error occurred: " + e.getMessage());
}
}
/** Test that if the % of timeouts is higher than the threshold that the circuit trips. */
@Test
public void testTripCircuitOnTimeoutsAboveThreshold() {
String key = "cmd-E";
try {
HystrixCommand<Boolean> cmd1 = new SuccessCommand(key, 60);
HystrixCircuitBreaker cb = cmd1.circuitBreaker;
// this should start as allowing requests
assertTrue(cb.allowRequest());
assertFalse(cb.isOpen());
// success with high latency
cmd1.execute();
HystrixCommand<Boolean> cmd2 = new SuccessCommand(key, 1);
cmd2.execute();
HystrixCommand<Boolean> cmd3 = new TimeoutCommand(key);
cmd3.execute();
HystrixCommand<Boolean> cmd4 = new SuccessCommand(key, 1);
cmd4.execute();
HystrixCommand<Boolean> cmd5 = new TimeoutCommand(key);
cmd5.execute();
HystrixCommand<Boolean> cmd6 = new TimeoutCommand(key);
cmd6.execute();
HystrixCommand<Boolean> cmd7 = new SuccessCommand(key, 1);
cmd7.execute();
HystrixCommand<Boolean> cmd8 = new TimeoutCommand(key);
cmd8.execute();
HystrixCommand<Boolean> cmd9 = new TimeoutCommand(key);
cmd9.execute();
// this should trip the circuit as the error percentage is above the threshold
Thread.sleep(100);
assertFalse(cb.allowRequest());
assertTrue(cb.isOpen());
} catch (Exception e) {
e.printStackTrace();
fail("Error occurred: " + e.getMessage());
}
}
/**
* Over a period of several 'windows' a single attempt will be made and fail and then finally
* succeed and close the circuit.
*
* <p>Ensure the circuit is kept open through the entire testing period and that only the single
* attempt in each window is made.
*/
@Test
public void testMultipleTimeWindowRetriesBeforeClosingCircuit() {
String key = "cmd-H";
try {
int sleepWindow = 200;
HystrixCommand<Boolean> cmd1 = new FailureCommand(key, 60);
HystrixCircuitBreaker cb = cmd1.circuitBreaker;
// this should start as allowing requests
assertTrue(cb.allowRequest());
assertFalse(cb.isOpen());
cmd1.execute();
HystrixCommand<Boolean> cmd2 = new FailureCommand(key, 1);
cmd2.execute();
HystrixCommand<Boolean> cmd3 = new FailureCommand(key, 1);
cmd3.execute();
HystrixCommand<Boolean> cmd4 = new TimeoutCommand(key);
cmd4.execute();
// everything has failed in the test window so we should return false now
System.out.println("!!!! 1 4 failures, circuit will open on recalc");
Thread.sleep(100);
assertFalse(cb.allowRequest());
assertTrue(cb.isOpen());
// wait for sleepWindow to pass
System.out.println("!!!! 2 Sleep window starting where all commands fail-fast");
Thread.sleep(sleepWindow + 50);
System.out.println("!!!! 3 Sleep window over, should allow singleTest()");
// but the circuit should still be open
assertTrue(cb.isOpen());
// we should now allow 1 request, and upon failure, should not affect the circuit breaker,
// which should remain open
HystrixCommand<Boolean> cmd5 = new FailureCommand(key, 60);
Observable<Boolean> asyncResult5 = cmd5.observe();
System.out.println("!!!! Kicked off the single-test");
// and further requests are still blocked while the singleTest command is in flight
assertFalse(cb.allowRequest());
System.out.println("!!!! Confirmed that no other requests go out during single-test");
asyncResult5.toBlocking().single();
System.out.println("!!!! SingleTest just completed");
// all requests should still be blocked, because the singleTest failed
assertFalse(cb.allowRequest());
assertFalse(cb.allowRequest());
assertFalse(cb.allowRequest());
// wait for sleepWindow to pass
System.out.println("!!!! 2nd sleep window START");
Thread.sleep(sleepWindow + 50);
System.out.println("!!!! 2nd sleep window over");
// we should now allow 1 request, and upon failure, should not affect the circuit breaker,
// which should remain open
HystrixCommand<Boolean> cmd6 = new FailureCommand(key, 60);
Observable<Boolean> asyncResult6 = cmd6.observe();
System.out.println("2nd singleTest just kicked off");
// and further requests are still blocked while the singleTest command is in flight
assertFalse(cb.allowRequest());
System.out.println("confirmed that 2nd singletest only happened once");
asyncResult6.toBlocking().single();
System.out.println("2nd singleTest now over");
// all requests should still be blocked, because the singleTest failed
assertFalse(cb.allowRequest());
assertFalse(cb.allowRequest());
assertFalse(cb.allowRequest());
// wait for sleepWindow to pass
Thread.sleep(sleepWindow + 50);
// but the circuit should still be open
assertTrue(cb.isOpen());
// we should now allow 1 request, and upon success, should cause the circuit to be closed
HystrixCommand<Boolean> cmd7 = new SuccessCommand(key, 60);
Observable<Boolean> asyncResult7 = cmd7.observe();
// and further requests are still blocked while the singleTest command is in flight
assertFalse(cb.allowRequest());
asyncResult7.toBlocking().single();
// all requests should be open again
assertTrue(cb.allowRequest());
assertTrue(cb.allowRequest());
assertTrue(cb.allowRequest());
// and the circuit should be closed again
assertFalse(cb.isOpen());
// and the circuit should be closed again
assertFalse(cb.isOpen());
} catch (Exception e) {
e.printStackTrace();
fail("Error occurred: " + e.getMessage());
}
}
