fixes

Author: hmottestad

core/http/client/src/main/java/org/eclipse/rdf4j/http/client/QueryCircuitBreaker.java

@@ -152,7 +152,7 @@ public void beforeExecution(QueryCircuitBreakerHandle handle) throws QueryInterr
 		}
 
 		if (state.rejectsNewQueries()) {
-			System.gc();
+			maybeRunCheckpointGc();
 			rejectCount.incrementAndGet();
 			if (state == QueryPressureState.CRITICAL) {
 				cancelOneHeavyQueryIfNeeded(configuration, snapshot, "critical-admission");
@@ -270,8 +270,9 @@ private QueryPressureState refreshState(String reason, Configuration configurati
 			LOGGER.info(
 					"Query circuit breaker transition previous={} current={} freeMb={} rollingGcMs={} reason={}",
 					previous, next, snapshot.getFreeMemoryMb(), snapshot.getRollingGcMs(), reason);
-			if (!isCheckpointReason(reason) && shouldRequestTransitionGc(currentState, configuration, snapshot)) {
-				System.gc();
+			if (!isCheckpointReason(reason) && !isMonitorReason(reason)
+					&& shouldRequestTransitionGc(currentState, configuration, snapshot)) {
+				maybeRunCheckpointGc();
 			}
 		}
 		if (!throttlesNewQueriesAtEntry(currentState, configuration)) {
@@ -315,6 +316,10 @@ private boolean isCheckpointReason(String reason) {
 		return reason.startsWith("checkpoint:");
 	}
 
+	private boolean isMonitorReason(String reason) {
+		return "monitor".equals(reason);
+	}
+
 	private boolean shouldRequestTransitionGc(QueryPressureState state, Configuration configuration,
 			QueryPressureMonitor.Snapshot snapshot) {
 		return state == QueryPressureState.HIGH

core/http/client/src/main/java/org/eclipse/rdf4j/http/client/QueryExecutionContext.java

@@ -20,12 +20,12 @@
  */
 public final class QueryExecutionContext {
 
-	private static boolean ignoreCheckpointStride = false;
+	private static volatile boolean ignoreCheckpointStride = false;
 	private static final int CHECKPOINT_STRIDE = 1024;
 	private static final int CHECKPOINT_MASK = CHECKPOINT_STRIDE - 1;
 	private static final ThreadLocal<State> CURRENT = new ThreadLocal<>();
-	private static boolean heavyOperatorExecutionEnabled = true;
-	private static int checkpointCalls;
+	private static volatile boolean heavyOperatorExecutionEnabled = true;
+	private static volatile int checkpointCalls;
 
 	private QueryExecutionContext() {
 	}

core/http/client/src/test/java/org/eclipse/rdf4j/http/client/QueryCircuitBreakerTest.java

@@ -262,6 +262,30 @@ void shouldRunMonitorGcEverySecondInCriticalMemoryMode() {
 		assertEquals(List.of(0L, 1000L), fixture.gcInvocations);
 	}
 
+	@Test
+	void shouldThrottleGcRequestsForRejectedAdmissions() {
+		Fixture fixture = new Fixture();
+		QueryCircuitBreaker breaker = fixture.breaker(configuration(true, 100, 200, 300, 400, 300, 200, 25, 10, 1000,
+				7), 1000, () -> fixture.gcInvocations.add(fixture.clock.get()));
+
+		fixture.freeMemoryMb.set(250);
+		QueryCircuitBreakerHandle firstHandle = breaker.register(QueryCircuitBreakerHandle.Source.SERVER, "repo",
+				"first-rejected-query");
+		QueryCircuitBreakerHandle secondHandle = breaker.register(QueryCircuitBreakerHandle.Source.SERVER, "repo",
+				"second-rejected-query");
+
+		try {
+			assertThrows(QueryCircuitBreaker.CircuitBreakerException.class, () -> breaker.beforeExecution(firstHandle));
+			assertThrows(QueryCircuitBreaker.CircuitBreakerException.class,
+					() -> breaker.beforeExecution(secondHandle));
+
+			assertEquals(List.of(0L), fixture.gcInvocations);
+		} finally {
+			breaker.complete(firstHandle);
+			breaker.complete(secondHandle);
+		}
+	}
+
 	@Test
 	void shouldBackOffCheckpointGcRequestsAndResetAfterLongPause() {
 		Fixture fixture = new Fixture();
@@ -439,6 +463,12 @@ void shouldCancelOnlyOneHeavyQueryPerCooldownWindow() {
 		breaker.complete(thirdAdmission);
 	}
 
+	@Test
+	void shouldSafelyPublishBreakerExecutionFlagsAcrossThreads() throws Exception {
+		assertTrue(isVolatile("heavyOperatorExecutionEnabled"));
+		assertTrue(isVolatile("ignoreCheckpointStride"));
+	}
+
 	private static QueryCircuitBreaker.Configuration configuration(boolean enabled, int warnGcMs, int highGcMs,
 			int criticalGcMs, int warnFreeMb, int highFreeMb, int criticalFreeMb, int warnAdmissionDelayMs,
 			int checkpointDelayMs, int cancelCooldownMs, int retryAfterSeconds) {
@@ -490,6 +520,11 @@ private static void resetCheckpointCalls() throws Exception {
 		field.setInt(null, 0);
 	}
 
+	private static boolean isVolatile(String fieldName) throws Exception {
+		Field field = QueryExecutionContext.class.getDeclaredField(fieldName);
+		return java.lang.reflect.Modifier.isVolatile(field.getModifiers());
+	}
+
 	private static Set<Long> threadIds(String threadName) {
 		Set<Long> ids = new HashSet<>();
 		for (Thread thread : Thread.getAllStackTraces().keySet()) {

core/sail/lmdb/pom.xml

@@ -237,18 +237,6 @@
 					</execution>
 				</executions>
 			</plugin>
-			<plugin>
-				<artifactId>maven-compiler-plugin</artifactId>
-				<configuration>
-					<annotationProcessorPaths>
-						<path>
-							<groupId>org.openjdk.jmh</groupId>
-							<artifactId>jmh-generator-annprocess</artifactId>
-							<version>${jmhVersion}</version>
-						</path>
-					</annotationProcessorPaths>
-				</configuration>
-			</plugin>
 			<plugin>
 				<artifactId>maven-assembly-plugin</artifactId>
 			</plugin>

tools/server-boot/src/test/java/org/eclipse/rdf4j/tools/serverboot/LmdbTimedOutQueryReadHandleTest.java

@@ -48,7 +48,7 @@
 import org.junit.jupiter.api.Test;
 import org.slf4j.LoggerFactory;
 import org.springframework.boot.test.context.SpringBootTest;
-import org.springframework.boot.web.server.LocalServerPort;
+import org.springframework.boot.test.web.server.LocalServerPort;
 import org.springframework.http.HttpStatus;
 
 import ch.qos.logback.classic.Logger;