SEBSERV-60 implemented

src/main/java/ch/ethz/seb/sebserver/gbl/async/AsyncService.java

@@ -40,18 +40,23 @@ public class AsyncService {
                 timeToRecover);
     }
 
-    public <T> MemoizingCircuitBreaker<T> createMemoizingCircuitBreaker(
+//    public <T> MemoizingCircuitBreaker<T> createMemoizingCircuitBreaker(
-            final Supplier<T> blockingSupplier) {
+//            final Supplier<T> blockingSupplier) {
-
+//
-        return new MemoizingCircuitBreaker<>(this.asyncRunner, blockingSupplier, true);
+//        return new MemoizingCircuitBreaker<>(
-    }
+//                this.asyncRunner,
+//                blockingSupplier,
+//                true,
+//                Constants.HOUR_IN_MILLIS);
+//    }
 
     public <T> MemoizingCircuitBreaker<T> createMemoizingCircuitBreaker(
             final Supplier<T> blockingSupplier,
             final int maxFailingAttempts,
             final long maxBlockingTime,
             final long timeToRecover,
-            final boolean momoized) {
+            final boolean momoized,
+            final long maxMemoizingTime) {
 
         return new MemoizingCircuitBreaker<>(
                 this.asyncRunner,
@@ -59,7 +64,8 @@ public class AsyncService {
                 maxFailingAttempts,
                 maxBlockingTime,
                 timeToRecover,
-                momoized);
+                momoized,
+                maxMemoizingTime);
     }
 
 }

src/main/java/ch/ethz/seb/sebserver/gbl/async/CircuitBreaker.java

@@ -102,6 +102,26 @@ public final class CircuitBreaker<T> {
         this.timeToRecover = timeToRecover;
     }
 
+    public int getMaxFailingAttempts() {
+        return this.maxFailingAttempts;
+    }
+
+    public long getMaxBlockingTime() {
+        return this.maxBlockingTime;
+    }
+
+    public long getTimeToRecover() {
+        return this.timeToRecover;
+    }
+
+    public AtomicInteger getFailingCount() {
+        return this.failingCount;
+    }
+
+    public long getLastSuccessTime() {
+        return this.lastSuccessTime;
+    }
+
     public Result<T> protectedRun(final Supplier<T> supplier) {
         final long currentTime = System.currentTimeMillis();
 

src/main/java/ch/ethz/seb/sebserver/gbl/async/MemoizingCircuitBreaker.java

@@ -54,21 +54,42 @@ public final class MemoizingCircuitBreaker<T> implements Supplier<Result<T>> {
     private final Supplier<T> supplier;
 
     private final boolean memoizing;
+    private final long maxMemoizingTime;
+    private long lastMemoizingTime = 0;
     private Result<T> cached = null;
 
     /** Create new CircuitBreakerSupplier.
      *
      * @param asyncRunner the AsyncRunner used to create asynchronous calls on the given supplier function
      * @param supplier The Supplier function that can fail or block for a long time
-     * @param memoizing whether the memoizing functionality is on or off */
+     * @param memoizing whether the memoizing functionality is on or off
+     * @param maxMemoizingTime the maximal time memorized data is valid */
     MemoizingCircuitBreaker(
             final AsyncRunner asyncRunner,
             final Supplier<T> supplier,
-            final boolean memoizing) {
+            final boolean memoizing,
+            final long maxMemoizingTime) {
 
         this.delegate = new CircuitBreaker<>(asyncRunner);
         this.supplier = supplier;
         this.memoizing = memoizing;
+        this.maxMemoizingTime = maxMemoizingTime;
+    }
+
+    public CircuitBreaker<T> getDelegate() {
+        return this.delegate;
+    }
+
+    public boolean isMemoizing() {
+        return this.memoizing;
+    }
+
+    public long getMaxMemoizingTime() {
+        return this.maxMemoizingTime;
+    }
+
+    public long getLastMemoizingTime() {
+        return this.lastMemoizingTime;
     }
 
     /** Create new CircuitBreakerSupplier.
@@ -79,14 +100,16 @@ public final class MemoizingCircuitBreaker<T> implements Supplier<Result<T>> {
      * @param maxBlockingTime the maximal time that an call attempt can block until an error is responded
      * @param timeToRecover the time the circuit breaker needs to cool-down on OPEN-STATE before going back to HALF_OPEN
      *            state
-     * @param memoizing whether the memoizing functionality is on or off */
+     * @param memoizing whether the memoizing functionality is on or off
+     * @param maxMemoizingTime the maximal time memorized data is valid */
     MemoizingCircuitBreaker(
             final AsyncRunner asyncRunner,
             final Supplier<T> supplier,
             final int maxFailingAttempts,
             final long maxBlockingTime,
             final long timeToRecover,
-            final boolean memoizing) {
+            final boolean memoizing,
+            final long maxMemoizingTime) {
 
         this.delegate = new CircuitBreaker<>(
                 asyncRunner,
@@ -95,6 +118,7 @@ public final class MemoizingCircuitBreaker<T> implements Supplier<Result<T>> {
                 timeToRecover);
         this.supplier = supplier;
         this.memoizing = memoizing;
+        this.maxMemoizingTime = maxMemoizingTime;
     }
 
     @Override
@@ -102,10 +126,15 @@ public final class MemoizingCircuitBreaker<T> implements Supplier<Result<T>> {
         final Result<T> result = this.delegate.protectedRun(this.supplier);
         if (result.hasError()) {
             if (this.memoizing && this.cached != null) {
-                if (log.isDebugEnabled()) {
+                final long currentTimeMillis = System.currentTimeMillis();
-                    log.debug("Return cached at: {}", System.currentTimeMillis());
+                if (currentTimeMillis - this.lastMemoizingTime > this.maxMemoizingTime) {
+                    if (log.isDebugEnabled()) {
+                        log.debug("Max memoizing time reached. Return original error");
+                    }
+                    return result;
                 }
 
+                log.warn("Return cached at: {}", System.currentTimeMillis());
                 return this.cached;
             }
 
@@ -117,6 +146,7 @@ public final class MemoizingCircuitBreaker<T> implements Supplier<Result<T>> {
                 }
 
                 this.cached = result;
+                this.lastMemoizingTime = System.currentTimeMillis();
             }
             return result;
         }

src/main/java/ch/ethz/seb/sebserver/webservice/servicelayer/lms/impl/OpenEdxLmsAPITemplate.java

@@ -46,6 +46,7 @@ import org.springframework.security.oauth2.common.OAuth2AccessToken;
 import org.springframework.util.LinkedMultiValueMap;
 import org.springframework.util.MultiValueMap;
 
+import ch.ethz.seb.sebserver.gbl.Constants;
 import ch.ethz.seb.sebserver.gbl.api.APIMessage;
 import ch.ethz.seb.sebserver.gbl.async.AsyncService;
 import ch.ethz.seb.sebserver.gbl.async.MemoizingCircuitBreaker;
@@ -97,7 +98,13 @@ final class OpenEdxLmsAPITemplate implements LmsAPITemplate {
             this.knownTokenAccessPaths.addAll(Arrays.asList(alternativeTokenRequestPaths));
         }
 
-        this.allQuizzesSupplier = asyncService.createMemoizingCircuitBreaker(allQuizzesSupplier());
+        this.allQuizzesSupplier = asyncService.createMemoizingCircuitBreaker(
+                allQuizzesSupplier(),
+                3,
+                Constants.MINUTE_IN_MILLIS,
+                Constants.MINUTE_IN_MILLIS,
+                true,
+                Constants.HOUR_IN_MILLIS);
     }
 
     @Override

src/test/java/ch/ethz/seb/sebserver/gbl/async/MemoizingCircuitBreakerTest.java

@@ -42,7 +42,7 @@ public class MemoizingCircuitBreakerTest {
     @Test
     public void roundtrip1() throws InterruptedException {
         final MemoizingCircuitBreaker<String> circuitBreaker = this.asyncService.createMemoizingCircuitBreaker(
-                tester(100, 5, 10), 3, 500, 1000, true);
+                tester(100, 5, 10), 3, 500, 1000, true, 1000);
 
         assertNull(circuitBreaker.getChached());
 
@@ -84,13 +84,39 @@ public class MemoizingCircuitBreakerTest {
 
     }
 
+    @Test
+    public void failing() throws InterruptedException {
+        final MemoizingCircuitBreaker<String> circuitBreaker = this.asyncService.createMemoizingCircuitBreaker(
+                tester(50, 1, 10), 3, 100, 100, true, 1000);
+
+        assertNull(circuitBreaker.getChached());
+
+        // fist call okay.. for memoizing
+        Result<String> result = circuitBreaker.get(); // 1. call...
+        assertFalse(result.hasError());
+        assertEquals("Hello", result.get());
+        assertTrue(circuitBreaker.getLastMemoizingTime() > 0);
+
+        // second call is okay from memoizing
+        Thread.sleep(100);
+        result = circuitBreaker.get(); // 2. call...
+        assertFalse(result.hasError());
+        assertEquals("Hello", result.get());
+        assertTrue(circuitBreaker.getLastMemoizingTime() > 0);
+
+        // third call is failing because of memoizing timeout
+        Thread.sleep(1000);
+        result = circuitBreaker.get(); // 3. call...
+        assertTrue(result.hasError());
+    }
+
     private Supplier<String> tester(final long delay, final int unavailableAfter, final int unavailableUntil) {
         final AtomicInteger count = new AtomicInteger(0);
         final AtomicBoolean wasUnavailable = new AtomicBoolean(false);
         return () -> {
             final int attempts = count.getAndIncrement();
 
-            log.info("tester answers {} {}", attempts, Thread.currentThread());
+            log.debug("tester answers {} {}", attempts, Thread.currentThread());
 
             try {
                 Thread.sleep(delay);
@@ -107,6 +133,4 @@ public class MemoizingCircuitBreakerTest {
         };
     }
 
-    // TODO timeout test: test also the behavior on timeout, is the thread being interrupted and released or not (should!)
-
 }

src/test/resources/logback-test.xml

@@ -0,0 +1,14 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<configuration debug="false" scan="false">
+    <appender name="STDOUT" class="ch.qos.logback.core.ConsoleAppender">
+        <encoder>
+            <pattern>%d{HH:mm:ss.SSS} %-5level [%thread]:[%logger] %msg%n</pattern>
+        </encoder>
+    </appender>
+ 
+    <Logger name="org.eth.demo.sebserver" level="TRACE" additivity="true" />
+
+    <root level="INFO" additivity="true">
+        <appender-ref ref="STDOUT" />
+    </root>
+</configuration>

src/test/resources/logback.xml

@@ -1,26 +0,0 @@
-<?xml version="1.0" encoding="UTF-8"?>
-<configuration debug="false" scan="false">
-    <appender name="STDOUT" class="ch.qos.logback.core.ConsoleAppender">
-        <encoder>
-            <pattern>%d{HH:mm:ss.SSS} %-5level [%thread]:[%logger] %msg%n</pattern>
-        </encoder>
-    </appender>
- 
-    <Logger name="org.eth.demo.sebserver" level="INFO" additivity="true" />
-    <Logger name="org.mybatis.generator" level="INFO" additivity="true" />
-    <Logger name="org.eth.demo.sebserver.batis" level="INFO" additivity="true" />
-    <Logger name="org.springframework.security" level="INFO" additivity="true" />
-    <Logger name="org.springframework.security.oauth2" level="INFO" additivity="true" />
-    <Logger name="org.springframework.web.socket.messaging" level="INFO" additivity="true" />
-    <Logger name="org.springframework.messaging" level="INFO" additivity="true" />
-    
-    
-    <Logger name="org.springframework" level="INFO" additivity="true" />
-    <Logger name="org.springframework.web" level="INFO" additivity="true" />
-    
-    <Logger name="org.eth.demo.sebserver.batis.gen.mapper.ExamRecordMapper" level="INFO" additivity="true" />
-
-    <root level="INFO" additivity="true">
-        <appender-ref ref="STDOUT" />
-    </root>
-</configuration>