Added EHcache for caching and improved Moodle asnyc loading

pom.xml

@@ -290,11 +290,15 @@
       <artifactId>flyway-core</artifactId>
     </dependency>
 
-    <!-- JMX -->
+    <!-- EHCache -->
-    <!-- <dependency> -->
+    <dependency>
-    <!-- <groupId>org.jolokia</groupId> -->
+      <groupId>org.ehcache</groupId>
-    <!-- <artifactId>jolokia-core</artifactId> -->
+      <artifactId>ehcache</artifactId>
-    <!-- </dependency> -->
+    </dependency>
+    <dependency>
+      <groupId>javax.cache</groupId>
+      <artifactId>cache-api</artifactId>
+    </dependency>
 
     <!-- Apache HTTP -->
     <dependency>

src/main/java/ch/ethz/seb/sebserver/SEBServer.java

@@ -15,7 +15,6 @@ import org.springframework.boot.autoconfigure.SpringBootApplication;
 import org.springframework.boot.autoconfigure.security.servlet.UserDetailsServiceAutoConfiguration;
 import org.springframework.boot.web.embedded.tomcat.TomcatServletWebServerFactory;
 import org.springframework.boot.web.servlet.server.ServletWebServerFactory;
-import org.springframework.cache.annotation.EnableCaching;
 import org.springframework.context.ApplicationContext;
 import org.springframework.context.annotation.Bean;
 import org.springframework.core.env.Environment;
@@ -40,7 +39,6 @@ import ch.ethz.seb.sebserver.gbl.profile.ProdWebServiceProfile;
 @SpringBootApplication(exclude = {
         UserDetailsServiceAutoConfiguration.class,
 })
-@EnableCaching
 public class SEBServer {
 
     public static void main(final String[] args) {

src/main/java/ch/ethz/seb/sebserver/gui/content/QuizLookupList.java

@@ -45,6 +45,7 @@ import ch.ethz.seb.sebserver.gui.service.page.impl.ModalInputDialog;
 import ch.ethz.seb.sebserver.gui.service.page.impl.PageAction;
 import ch.ethz.seb.sebserver.gui.service.remote.webservice.api.RestService;
 import ch.ethz.seb.sebserver.gui.service.remote.webservice.api.exam.CheckExamImported;
+import ch.ethz.seb.sebserver.gui.service.remote.webservice.api.quiz.GetQuizData;
 import ch.ethz.seb.sebserver.gui.service.remote.webservice.api.quiz.GetQuizPage;
 import ch.ethz.seb.sebserver.gui.service.remote.webservice.auth.CurrentUser;
 import ch.ethz.seb.sebserver.gui.service.remote.webservice.auth.CurrentUser.GrantCheck;
@@ -297,7 +298,11 @@ public class QuizLookupList implements TemplateComposer {
             final QuizData quizData,
             final Function<String, String> institutionNameFunction) {
 
-        action.getSingleSelection();
+        final QuizData fullQuizData = this.pageService.getRestService().getBuilder(GetQuizData.class)
+                .withURIVariable(API.PARAM_MODEL_ID, quizData.getModelId())
+                .withQueryParam(QuizData.QUIZ_ATTR_LMS_SETUP_ID, String.valueOf(quizData.lmsSetupId))
+                .call()
+                .getOr(quizData);
 
         final ModalInputDialog<Void> dialog = new ModalInputDialog<Void>(
                 action.pageContext().getParent().getShell(),
@@ -307,7 +312,7 @@ public class QuizLookupList implements TemplateComposer {
         dialog.open(
                 DETAILS_TITLE_TEXT_KEY,
                 action.pageContext(),
-                pc -> createDetailsForm(quizData, pc, institutionNameFunction));
+                pc -> createDetailsForm(fullQuizData, pc, institutionNameFunction));
 
         return action;
     }

src/main/java/ch/ethz/seb/sebserver/webservice/CacheConfig.java

@@ -0,0 +1,66 @@
+/*
+ * Copyright (c) 2021 ETH Zürich, Educational Development and Technology (LET)
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ */
+
+package ch.ethz.seb.sebserver.webservice;
+
+import java.net.URI;
+import java.net.URISyntaxException;
+import java.util.Arrays;
+
+import javax.cache.Caching;
+import javax.cache.spi.CachingProvider;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.springframework.beans.factory.annotation.Value;
+import org.springframework.cache.CacheManager;
+import org.springframework.cache.annotation.EnableCaching;
+import org.springframework.cache.concurrent.ConcurrentMapCacheManager;
+import org.springframework.cache.jcache.JCacheCacheManager;
+import org.springframework.cache.jcache.config.JCacheConfigurerSupport;
+import org.springframework.cache.support.CompositeCacheManager;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+
+import ch.ethz.seb.sebserver.gbl.profile.WebServiceProfile;
+
+@EnableCaching
+@WebServiceProfile
+@Configuration
+public class CacheConfig extends JCacheConfigurerSupport {
+
+    private static final Logger log = LoggerFactory.getLogger(CacheConfig.class);
+
+    @Value("${spring.cache.jcache.config}")
+    String jCacheConfig;
+
+    @Override
+    @Bean
+    public CacheManager cacheManager() {
+        try {
+            final CachingProvider cachingProvider = Caching.getCachingProvider();
+            final javax.cache.CacheManager cacheManager =
+                    cachingProvider.getCacheManager(new URI(this.jCacheConfig), this.getClass().getClassLoader());
+            System.out.println("cacheManager:" + cacheManager);
+
+            final CompositeCacheManager composite = new CompositeCacheManager();
+            composite.setCacheManagers(Arrays.asList(
+                    new JCacheCacheManager(cacheManager),
+                    new ConcurrentMapCacheManager()));
+            composite.setFallbackToNoOpCache(true);
+
+            return composite;
+
+        } catch (final URISyntaxException e) {
+            log.error("Failed to initialize caching with EHCache. Fallback to simple caching");
+            return new ConcurrentMapCacheManager();
+        }
+
+    }
+
+}

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

@@ -20,55 +20,81 @@ import java.util.stream.Collectors;
 
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
+import org.springframework.core.env.Environment;
 
 import ch.ethz.seb.sebserver.gbl.Constants;
 import ch.ethz.seb.sebserver.gbl.async.AsyncService;
 import ch.ethz.seb.sebserver.gbl.async.CircuitBreaker;
-import ch.ethz.seb.sebserver.gbl.async.MemoizingCircuitBreaker;
 import ch.ethz.seb.sebserver.gbl.model.exam.Chapters;
 import ch.ethz.seb.sebserver.gbl.model.exam.QuizData;
 import ch.ethz.seb.sebserver.gbl.model.user.ExamineeAccountDetails;
 import ch.ethz.seb.sebserver.gbl.util.Result;
 import ch.ethz.seb.sebserver.webservice.servicelayer.dao.FilterMap;
-import ch.ethz.seb.sebserver.webservice.servicelayer.lms.LmsAPIService;
 
 public abstract class CourseAccess {
 
     private static final Logger log = LoggerFactory.getLogger(CourseAccess.class);
 
-    protected final MemoizingCircuitBreaker<List<QuizData>> allQuizzesRequest;
+    public enum FetchStatus {
+        ALL_FETCHED,
+        ASYNC_FETCH_RUNNING,
+        FETCH_ERROR
+    }
+
     protected final CircuitBreaker<List<QuizData>> quizzesRequest;
     protected final CircuitBreaker<Chapters> chaptersRequest;
     protected final CircuitBreaker<ExamineeAccountDetails> accountDetailRequest;
 
-    protected CourseAccess(final AsyncService asyncService) {
+    protected CourseAccess(
-        this.allQuizzesRequest = asyncService.createMemoizingCircuitBreaker(
+            final AsyncService asyncService,
-                allQuizzesSupplier(null),
+            final Environment environment) {
-                3,
-                Constants.MINUTE_IN_MILLIS,
-                Constants.MINUTE_IN_MILLIS,
-                true,
-                Constants.HOUR_IN_MILLIS);
 
         this.quizzesRequest = asyncService.createCircuitBreaker(
-                3,
+                environment.getProperty(
-                Constants.MINUTE_IN_MILLIS,
+                        "sebserver.webservice.circuitbreaker.quizzesRequest.attempts",
-                Constants.MINUTE_IN_MILLIS);
+                        Integer.class,
+                        3),
+                environment.getProperty(
+                        "sebserver.webservice.circuitbreaker.quizzesRequest.blockingTime",
+                        Long.class,
+                        Constants.MINUTE_IN_MILLIS),
+                environment.getProperty(
+                        "sebserver.webservice.circuitbreaker.quizzesRequest.timeToRecover",
+                        Long.class,
+                        Constants.MINUTE_IN_MILLIS));
 
         this.chaptersRequest = asyncService.createCircuitBreaker(
-                3,
+                environment.getProperty(
-                Constants.SECOND_IN_MILLIS * 10,
+                        "sebserver.webservice.circuitbreaker.chaptersRequest.attempts",
-                Constants.MINUTE_IN_MILLIS);
+                        Integer.class,
+                        3),
+                environment.getProperty(
+                        "sebserver.webservice.circuitbreaker.chaptersRequest.blockingTime",
+                        Long.class,
+                        Constants.SECOND_IN_MILLIS * 10),
+                environment.getProperty(
+                        "sebserver.webservice.circuitbreaker.chaptersRequest.timeToRecover",
+                        Long.class,
+                        Constants.MINUTE_IN_MILLIS));
 
         this.accountDetailRequest = asyncService.createCircuitBreaker(
-                1,
+                environment.getProperty(
-                Constants.SECOND_IN_MILLIS * 10,
+                        "sebserver.webservice.circuitbreaker.accountDetailRequest.attempts",
-                Constants.SECOND_IN_MILLIS * 10);
+                        Integer.class,
+                        2),
+                environment.getProperty(
+                        "sebserver.webservice.circuitbreaker.accountDetailRequest.blockingTime",
+                        Long.class,
+                        Constants.SECOND_IN_MILLIS * 10),
+                environment.getProperty(
+                        "sebserver.webservice.circuitbreaker.accountDetailRequest.timeToRecover",
+                        Long.class,
+                        Constants.SECOND_IN_MILLIS * 10));
     }
 
     public Result<Collection<Result<QuizData>>> getQuizzesFromCache(final Set<String> ids) {
         return Result.tryCatch(() -> {
-            final List<QuizData> cached = this.allQuizzesRequest.getCached();
+            final List<QuizData> cached = allQuizzesSupplier().getAllCached();
             final List<QuizData> available = (cached != null)
                     ? cached
                     : quizzesSupplier(ids).get();
@@ -101,11 +127,7 @@ public abstract class CourseAccess {
     }
 
     public Result<List<QuizData>> getQuizzes(final FilterMap filterMap) {
-        if (filterMap != null) {
+        return allQuizzesSupplier().getAll(filterMap);
-            this.allQuizzesRequest.setSupplier(allQuizzesSupplier(filterMap));
-        }
-        return this.allQuizzesRequest.get()
-                .map(LmsAPIService.quizzesFilterFunction(filterMap));
     }
 
     public Result<ExamineeAccountDetails> getExamineeAccountDetails(final String examineeSessionId) {
@@ -139,8 +161,16 @@ public abstract class CourseAccess {
 
     protected abstract Supplier<List<QuizData>> quizzesSupplier(final Set<String> ids);
 
-    protected abstract Supplier<List<QuizData>> allQuizzesSupplier(final FilterMap filterMap);
+    protected abstract AllQuizzesSupplier allQuizzesSupplier();
 
     protected abstract Supplier<Chapters> getCourseChaptersSupplier(final String courseId);
 
+    protected abstract FetchStatus getFetchStatus();
+
+    protected interface AllQuizzesSupplier {
+        List<QuizData> getAllCached();
+
+        Result<List<QuizData>> getAll(final FilterMap filterMap);
+    }
+
 }

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

@@ -20,6 +20,7 @@ import java.util.stream.Collectors;
 import org.apache.commons.lang3.StringUtils;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
+import org.springframework.core.env.Environment;
 import org.springframework.http.HttpEntity;
 import org.springframework.http.HttpHeaders;
 import org.springframework.http.HttpMethod;
@@ -41,6 +42,8 @@ import com.fasterxml.jackson.core.type.TypeReference;
 import ch.ethz.seb.sebserver.gbl.Constants;
 import ch.ethz.seb.sebserver.gbl.api.JSONMapper;
 import ch.ethz.seb.sebserver.gbl.async.AsyncService;
+import ch.ethz.seb.sebserver.gbl.async.CircuitBreaker.State;
+import ch.ethz.seb.sebserver.gbl.async.MemoizingCircuitBreaker;
 import ch.ethz.seb.sebserver.gbl.model.exam.Chapters;
 import ch.ethz.seb.sebserver.gbl.model.exam.QuizData;
 import ch.ethz.seb.sebserver.gbl.model.institution.LmsSetup;
@@ -70,6 +73,8 @@ final class OpenEdxCourseAccess extends CourseAccess {
     private final LmsSetup lmsSetup;
     private final OpenEdxRestTemplateFactory openEdxRestTemplateFactory;
     private final WebserviceInfo webserviceInfo;
+    private final MemoizingCircuitBreaker<List<QuizData>> allQuizzesRequest;
+    private final AllQuizzesSupplier allQuizzesSupplier;
 
     private OAuth2RestTemplate restTemplate;
 
@@ -78,13 +83,51 @@ final class OpenEdxCourseAccess extends CourseAccess {
             final LmsSetup lmsSetup,
             final OpenEdxRestTemplateFactory openEdxRestTemplateFactory,
             final WebserviceInfo webserviceInfo,
-            final AsyncService asyncService) {
+            final AsyncService asyncService,
+            final Environment environment) {
 
-        super(asyncService);
+        super(asyncService, environment);
         this.jsonMapper = jsonMapper;
         this.lmsSetup = lmsSetup;
         this.openEdxRestTemplateFactory = openEdxRestTemplateFactory;
         this.webserviceInfo = webserviceInfo;
+
+        this.allQuizzesRequest = asyncService.createMemoizingCircuitBreaker(
+                quizzesSupplier(),
+                environment.getProperty(
+                        "sebserver.webservice.circuitbreaker.allQuizzesRequest.attempts",
+                        Integer.class,
+                        3),
+                environment.getProperty(
+                        "sebserver.webservice.circuitbreaker.allQuizzesRequest.blockingTime",
+                        Long.class,
+                        Constants.MINUTE_IN_MILLIS),
+                environment.getProperty(
+                        "sebserver.webservice.circuitbreaker.allQuizzesRequest.timeToRecover",
+                        Long.class,
+                        Constants.MINUTE_IN_MILLIS),
+                environment.getProperty(
+                        "sebserver.webservice.circuitbreaker.allQuizzesRequest.memoize",
+                        Boolean.class,
+                        true),
+                environment.getProperty(
+                        "sebserver.webservice.circuitbreaker.allQuizzesRequest.memoizingTime",
+                        Long.class,
+                        Constants.HOUR_IN_MILLIS));
+
+        this.allQuizzesSupplier = new AllQuizzesSupplier() {
+
+            @Override
+            public List<QuizData> getAllCached() {
+                return OpenEdxCourseAccess.this.allQuizzesRequest.getCached();
+            }
+
+            @Override
+            public Result<List<QuizData>> getAll(final FilterMap filterMap) {
+                return OpenEdxCourseAccess.this.allQuizzesRequest.get();
+            }
+
+        };
     }
 
     LmsSetupTestResult initAPIAccess() {
@@ -173,8 +216,7 @@ final class OpenEdxCourseAccess extends CourseAccess {
                 .getOrThrow();
     }
 
-    @Override
+    private Supplier<List<QuizData>> quizzesSupplier() {
-    protected Supplier<List<QuizData>> allQuizzesSupplier(final FilterMap filterMap) {
         return () -> getRestTemplate()
                 .map(this::collectAllQuizzes)
                 .getOrThrow();
@@ -451,4 +493,17 @@ final class OpenEdxCourseAccess extends CourseAccess {
         return Result.of(this.restTemplate);
     }
 
+    @Override
+    protected FetchStatus getFetchStatus() {
+        if (this.allQuizzesRequest.getState() != State.CLOSED) {
+            return FetchStatus.FETCH_ERROR;
+        }
+        return FetchStatus.ALL_FETCHED;
+    }
+
+    @Override
+    protected AllQuizzesSupplier allQuizzesSupplier() {
+        return this.allQuizzesSupplier;
+    }
+
 }

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

@@ -11,6 +11,7 @@ package ch.ethz.seb.sebserver.webservice.servicelayer.lms.impl.edx;
 import org.apache.commons.lang3.StringUtils;
 import org.springframework.beans.factory.annotation.Value;
 import org.springframework.context.annotation.Lazy;
+import org.springframework.core.env.Environment;
 import org.springframework.stereotype.Service;
 
 import ch.ethz.seb.sebserver.ClientHttpRequestFactoryService;
@@ -33,6 +34,7 @@ public class OpenEdxLmsAPITemplateFactory {
     private final JSONMapper jsonMapper;
     private final WebserviceInfo webserviceInfo;
     private final AsyncService asyncService;
+    private final Environment environment;
     private final ClientCredentialService clientCredentialService;
     private final ClientHttpRequestFactoryService clientHttpRequestFactoryService;
     private final String[] alternativeTokenRequestPaths;
@@ -42,6 +44,7 @@ public class OpenEdxLmsAPITemplateFactory {
             final JSONMapper jsonMapper,
             final WebserviceInfo webserviceInfo,
             final AsyncService asyncService,
+            final Environment environment,
             final ClientCredentialService clientCredentialService,
             final ClientHttpRequestFactoryService clientHttpRequestFactoryService,
             @Value("${sebserver.webservice.lms.openedx.api.token.request.paths}") final String alternativeTokenRequestPaths,
@@ -50,6 +53,7 @@ public class OpenEdxLmsAPITemplateFactory {
         this.jsonMapper = jsonMapper;
         this.webserviceInfo = webserviceInfo;
         this.asyncService = asyncService;
+        this.environment = environment;
         this.clientCredentialService = clientCredentialService;
         this.clientHttpRequestFactoryService = clientHttpRequestFactoryService;
         this.alternativeTokenRequestPaths = (alternativeTokenRequestPaths != null)
@@ -78,7 +82,8 @@ public class OpenEdxLmsAPITemplateFactory {
                     lmsSetup,
                     openEdxRestTemplateFactory,
                     this.webserviceInfo,
-                    this.asyncService);
+                    this.asyncService,
+                    this.environment);
 
             final OpenEdxCourseRestriction openEdxCourseRestriction = new OpenEdxCourseRestriction(
                     lmsSetup,

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

@@ -23,6 +23,7 @@ import org.apache.commons.lang3.StringUtils;
 import org.joda.time.DateTime;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
+import org.springframework.core.env.Environment;
 import org.springframework.util.LinkedMultiValueMap;
 import org.springframework.util.MultiValueMap;
 
@@ -34,6 +35,7 @@ import com.fasterxml.jackson.core.type.TypeReference;
 import ch.ethz.seb.sebserver.gbl.Constants;
 import ch.ethz.seb.sebserver.gbl.api.JSONMapper;
 import ch.ethz.seb.sebserver.gbl.async.AsyncService;
+import ch.ethz.seb.sebserver.gbl.async.CircuitBreaker;
 import ch.ethz.seb.sebserver.gbl.model.exam.Chapters;
 import ch.ethz.seb.sebserver.gbl.model.exam.QuizData;
 import ch.ethz.seb.sebserver.gbl.model.institution.LmsSetup;
@@ -43,6 +45,7 @@ import ch.ethz.seb.sebserver.gbl.util.Result;
 import ch.ethz.seb.sebserver.gbl.util.Utils;
 import ch.ethz.seb.sebserver.webservice.servicelayer.dao.FilterMap;
 import ch.ethz.seb.sebserver.webservice.servicelayer.lms.impl.CourseAccess;
+import ch.ethz.seb.sebserver.webservice.servicelayer.lms.impl.moodle.MoodleCourseDataAsyncLoader.CourseDataShort;
 import ch.ethz.seb.sebserver.webservice.servicelayer.lms.impl.moodle.MoodleRestTemplateFactory.MoodleAPIRestTemplate;
 
 /** Implements the LmsAPITemplate for Open edX LMS Course API access.
@@ -73,7 +76,9 @@ public class MoodleCourseAccess extends CourseAccess {
     private final JSONMapper jsonMapper;
     private final LmsSetup lmsSetup;
     private final MoodleRestTemplateFactory moodleRestTemplateFactory;
-    private final MoodleCourseDataLazyLoader moodleCourseDataLazyLoader;
+    private final MoodleCourseDataAsyncLoader moodleCourseDataAsyncLoader;
+    private final CircuitBreaker<List<QuizData>> allQuizzesRequest;
+    private final AllQuizzesSupplier allQuizzesSupplier;
 
     private MoodleAPIRestTemplate restTemplate;
 
@@ -81,14 +86,42 @@ public class MoodleCourseAccess extends CourseAccess {
             final JSONMapper jsonMapper,
             final LmsSetup lmsSetup,
             final MoodleRestTemplateFactory moodleRestTemplateFactory,
-            final MoodleCourseDataLazyLoader moodleCourseDataLazyLoader,
+            final MoodleCourseDataAsyncLoader moodleCourseDataAsyncLoader,
-            final AsyncService asyncService) {
+            final AsyncService asyncService,
+            final Environment environment) {
 
-        super(asyncService);
+        super(asyncService, environment);
         this.jsonMapper = jsonMapper;
         this.lmsSetup = lmsSetup;
-        this.moodleCourseDataLazyLoader = moodleCourseDataLazyLoader;
+        this.moodleCourseDataAsyncLoader = moodleCourseDataAsyncLoader;
         this.moodleRestTemplateFactory = moodleRestTemplateFactory;
+
+        this.allQuizzesRequest = asyncService.createCircuitBreaker(
+                environment.getProperty(
+                        "sebserver.webservice.circuitbreaker.allQuizzesRequest.attempts",
+                        Integer.class,
+                        3),
+                environment.getProperty(
+                        "sebserver.webservice.circuitbreaker.allQuizzesRequest.blockingTime",
+                        Long.class,
+                        Constants.MINUTE_IN_MILLIS),
+                environment.getProperty(
+                        "sebserver.webservice.circuitbreaker.allQuizzesRequest.timeToRecover",
+                        Long.class,
+                        Constants.MINUTE_IN_MILLIS));
+
+        this.allQuizzesSupplier = new AllQuizzesSupplier() {
+
+            @Override
+            public List<QuizData> getAllCached() {
+                return getCached();
+            }
+
+            @Override
+            public Result<List<QuizData>> getAll(final FilterMap filterMap) {
+                return MoodleCourseAccess.this.allQuizzesRequest.protectedRun(allQuizzesSupplier(filterMap));
+            }
+        };
     }
 
     @Override
@@ -175,7 +208,6 @@ public class MoodleCourseAccess extends CourseAccess {
 
     }
 
-    @Override
     protected Supplier<List<QuizData>> allQuizzesSupplier(final FilterMap filterMap) {
         return () -> getRestTemplate()
                 .map(template -> collectAllQuizzes(template, filterMap))
@@ -187,6 +219,20 @@ public class MoodleCourseAccess extends CourseAccess {
         throw new UnsupportedOperationException("not available yet");
     }
 
+    @Override
+    protected FetchStatus getFetchStatus() {
+        if (this.moodleCourseDataAsyncLoader.isRunning()) {
+            return FetchStatus.ASYNC_FETCH_RUNNING;
+        }
+
+        return FetchStatus.ALL_FETCHED;
+    }
+
+    @Override
+    protected AllQuizzesSupplier allQuizzesSupplier() {
+        return this.allQuizzesSupplier;
+    }
+
     private List<QuizData> collectAllQuizzes(
             final MoodleAPIRestTemplate restTemplate,
             final FilterMap filterMap) {
@@ -198,42 +244,42 @@ public class MoodleCourseAccess extends CourseAccess {
         final DateTime quizFromTime = (filterMap != null) ? filterMap.getQuizFromTime() : null;
         final long fromCutTime = (quizFromTime != null) ? Utils.toUnixTimeInSeconds(quizFromTime) : -1;
 
-        Collection<CourseData> courseQuizData = Collections.emptyList();
+        Collection<CourseDataShort> courseQuizData = Collections.emptyList();
-        if (this.moodleCourseDataLazyLoader.isRunning()) {
+        if (this.moodleCourseDataAsyncLoader.isRunning()) {
-            courseQuizData = this.moodleCourseDataLazyLoader.getPreFilteredCourseIds();
+            courseQuizData = this.moodleCourseDataAsyncLoader.getCachedCourseData();
-        } else if (this.moodleCourseDataLazyLoader.getLastRunTime() <= 0) {
+        } else if (this.moodleCourseDataAsyncLoader.getLastRunTime() <= 0) {
             // set cut time if available
             if (fromCutTime >= 0) {
-                this.moodleCourseDataLazyLoader.setFromCutTime(fromCutTime);
+                this.moodleCourseDataAsyncLoader.setFromCutTime(fromCutTime);
             }
             // first run async and wait some time, get what is there
-            this.moodleCourseDataLazyLoader.loadAsync(restTemplate);
+            this.moodleCourseDataAsyncLoader.loadAsync(restTemplate);
             try {
                 Thread.sleep(INITIAL_WAIT_TIME);
-                courseQuizData = this.moodleCourseDataLazyLoader.getPreFilteredCourseIds();
+                courseQuizData = this.moodleCourseDataAsyncLoader.getCachedCourseData();
             } catch (final Exception e) {
                 log.error("Failed to wait for first load run: ", e);
                 return Collections.emptyList();
             }
-        } else if (this.moodleCourseDataLazyLoader.isLongRunningTask()) {
+        } else if (this.moodleCourseDataAsyncLoader.isLongRunningTask()) {
             // on long running tasks if we have a different fromCutTime as before
             // kick off the lazy loading task immediately with the new time filter
-            if (fromCutTime > 0 && fromCutTime != this.moodleCourseDataLazyLoader.getFromCutTime()) {
+            if (fromCutTime > 0 && fromCutTime != this.moodleCourseDataAsyncLoader.getFromCutTime()) {
-                this.moodleCourseDataLazyLoader.setFromCutTime(fromCutTime);
+                this.moodleCourseDataAsyncLoader.setFromCutTime(fromCutTime);
-                this.moodleCourseDataLazyLoader.loadAsync(restTemplate);
+                this.moodleCourseDataAsyncLoader.loadAsync(restTemplate);
                 // otherwise kick off only if the last fetch task was then minutes ago
-            } else if (Utils.getMillisecondsNow() - this.moodleCourseDataLazyLoader.getLastRunTime() > 10
+            } else if (Utils.getMillisecondsNow() - this.moodleCourseDataAsyncLoader.getLastRunTime() > 10
                     * Constants.MINUTE_IN_MILLIS) {
-                this.moodleCourseDataLazyLoader.loadAsync(restTemplate);
+                this.moodleCourseDataAsyncLoader.loadAsync(restTemplate);
             }
-            courseQuizData = this.moodleCourseDataLazyLoader.getPreFilteredCourseIds();
+            courseQuizData = this.moodleCourseDataAsyncLoader.getCachedCourseData();
         } else {
             // just run the task in sync
             if (fromCutTime >= 0) {
-                this.moodleCourseDataLazyLoader.setFromCutTime(fromCutTime);
+                this.moodleCourseDataAsyncLoader.setFromCutTime(fromCutTime);
             }
-            this.moodleCourseDataLazyLoader.loadSync(restTemplate);
+            this.moodleCourseDataAsyncLoader.loadSync(restTemplate);
-            courseQuizData = this.moodleCourseDataLazyLoader.getPreFilteredCourseIds();
+            courseQuizData = this.moodleCourseDataAsyncLoader.getCachedCourseData();
         }
 
         if (courseQuizData.isEmpty()) {
@@ -257,6 +303,29 @@ public class MoodleCourseAccess extends CourseAccess {
                         });
     }
 
+    private List<QuizData> getCached() {
+        final Collection<CourseDataShort> courseQuizData = this.moodleCourseDataAsyncLoader.getCachedCourseData();
+
+        final String urlPrefix = (this.lmsSetup.lmsApiUrl.endsWith(Constants.URL_PATH_SEPARATOR))
+                ? this.lmsSetup.lmsApiUrl + MOODLE_QUIZ_START_URL_PATH
+                : this.lmsSetup.lmsApiUrl + Constants.URL_PATH_SEPARATOR + MOODLE_QUIZ_START_URL_PATH;
+        return courseQuizData
+                .stream()
+                .reduce(
+                        new ArrayList<>(),
+                        (list, courseData) -> {
+                            list.addAll(quizDataOf(
+                                    this.lmsSetup,
+                                    courseData,
+                                    urlPrefix));
+                            return list;
+                        },
+                        (list1, list2) -> {
+                            list1.addAll(list2);
+                            return list1;
+                        });
+    }
+
     private List<QuizData> getQuizzesForIds(
             final MoodleAPIRestTemplate restTemplate,
             final Set<String> quizIds) {
@@ -405,6 +474,46 @@ public class MoodleCourseAccess extends CourseAccess {
         return courseAndQuiz;
     }
 
+    private List<QuizData> quizDataOf(
+            final LmsSetup lmsSetup,
+            final CourseDataShort courseData,
+            final String uriPrefix) {
+
+        additionalAttrs.clear();
+        additionalAttrs.put(QuizData.ATTR_ADDITIONAL_CREATION_TIME, String.valueOf(courseData.time_created));
+        additionalAttrs.put(QuizData.ATTR_ADDITIONAL_SHORT_NAME, courseData.short_name);
+        additionalAttrs.put(QuizData.ATTR_ADDITIONAL_ID_NUMBER, courseData.idnumber);
+
+        final List<QuizData> courseAndQuiz = courseData.quizzes
+                .stream()
+                .map(courseQuizData -> {
+                    final String startURI = uriPrefix + courseQuizData.course_module;
+                    //additionalAttrs.put(QuizData.ATTR_ADDITIONAL_TIME_LIMIT, String.valueOf(courseQuizData.time_limit));
+                    return new QuizData(
+                            getInternalQuizId(
+                                    courseQuizData.course_module,
+                                    courseData.id,
+                                    courseData.short_name,
+                                    courseData.idnumber),
+                            lmsSetup.getInstitutionId(),
+                            lmsSetup.id,
+                            lmsSetup.getLmsType(),
+                            courseQuizData.name,
+                            Constants.EMPTY_NOTE,
+                            (courseQuizData.time_open != null && courseQuizData.time_open > 0)
+                                    ? Utils.toDateTimeUTCUnix(courseQuizData.time_open)
+                                    : Utils.toDateTimeUTCUnix(courseData.start_date),
+                            (courseQuizData.time_close != null && courseQuizData.time_close > 0)
+                                    ? Utils.toDateTimeUTCUnix(courseQuizData.time_close)
+                                    : Utils.toDateTimeUTCUnix(courseData.end_date),
+                            startURI,
+                            additionalAttrs);
+                })
+                .collect(Collectors.toList());
+
+        return courseAndQuiz;
+    }
+
     private Result<MoodleAPIRestTemplate> getRestTemplate() {
         if (this.restTemplate == null) {
             final Result<MoodleAPIRestTemplate> templateRequest = this.moodleRestTemplateFactory
@@ -482,7 +591,7 @@ public class MoodleCourseAccess extends CourseAccess {
 
     /** Maps the Moodle course API course data */
     @JsonIgnoreProperties(ignoreUnknown = true)
-    static final class CourseData {
+    private static final class CourseData {
         final String id;
         final String short_name;
         final String idnumber;
@@ -516,35 +625,10 @@ public class MoodleCourseAccess extends CourseAccess {
             this.end_date = end_date;
             this.time_created = time_created;
         }
-
-        @Override
-        public int hashCode() {
-            final int prime = 31;
-            int result = 1;
-            result = prime * result + ((this.id == null) ? 0 : this.id.hashCode());
-            return result;
-        }
-
-        @Override
-        public boolean equals(final Object obj) {
-            if (this == obj)
-                return true;
-            if (obj == null)
-                return false;
-            if (getClass() != obj.getClass())
-                return false;
-            final CourseData other = (CourseData) obj;
-            if (this.id == null) {
-                if (other.id != null)
-                    return false;
-            } else if (!this.id.equals(other.id))
-                return false;
-            return true;
-        }
     }
 
     @JsonIgnoreProperties(ignoreUnknown = true)
-    static final class Courses {
+    private static final class Courses {
         final Collection<CourseData> courses;
 
         @JsonCreator
@@ -555,7 +639,7 @@ public class MoodleCourseAccess extends CourseAccess {
     }
 
     @JsonIgnoreProperties(ignoreUnknown = true)
-    static final class CourseQuizData {
+    private static final class CourseQuizData {
         final Collection<CourseQuiz> quizzes;
 
         @JsonCreator

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

@@ -28,8 +28,10 @@ import org.slf4j.LoggerFactory;
 import org.springframework.beans.factory.config.ConfigurableBeanFactory;
 import org.springframework.context.annotation.Lazy;
 import org.springframework.context.annotation.Scope;
+import org.springframework.core.env.Environment;
 import org.springframework.stereotype.Component;
 import org.springframework.util.LinkedMultiValueMap;
+import org.springframework.util.MultiValueMap;
 
 import com.fasterxml.jackson.annotation.JsonCreator;
 import com.fasterxml.jackson.annotation.JsonIgnoreProperties;
@@ -40,40 +42,72 @@ import com.fasterxml.jackson.databind.JsonMappingException;
 import ch.ethz.seb.sebserver.gbl.Constants;
 import ch.ethz.seb.sebserver.gbl.api.JSONMapper;
 import ch.ethz.seb.sebserver.gbl.async.AsyncRunner;
+import ch.ethz.seb.sebserver.gbl.async.AsyncService;
+import ch.ethz.seb.sebserver.gbl.async.CircuitBreaker;
 import ch.ethz.seb.sebserver.gbl.profile.WebServiceProfile;
 import ch.ethz.seb.sebserver.gbl.util.Utils;
-import ch.ethz.seb.sebserver.webservice.servicelayer.lms.impl.moodle.MoodleCourseAccess.CourseData;
-import ch.ethz.seb.sebserver.webservice.servicelayer.lms.impl.moodle.MoodleCourseAccess.CourseQuiz;
-import ch.ethz.seb.sebserver.webservice.servicelayer.lms.impl.moodle.MoodleCourseAccess.CourseQuizData;
-import ch.ethz.seb.sebserver.webservice.servicelayer.lms.impl.moodle.MoodleCourseAccess.Courses;
 import ch.ethz.seb.sebserver.webservice.servicelayer.lms.impl.moodle.MoodleRestTemplateFactory.MoodleAPIRestTemplate;
 
 @Lazy
 @Component
 @WebServiceProfile
 @Scope(ConfigurableBeanFactory.SCOPE_PROTOTYPE)
-public class MoodleCourseDataLazyLoader {
+public class MoodleCourseDataAsyncLoader {
 
-    private static final Logger log = LoggerFactory.getLogger(MoodleCourseDataLazyLoader.class);
+    private static final Logger log = LoggerFactory.getLogger(MoodleCourseDataAsyncLoader.class);
 
     private final JSONMapper jsonMapper;
     private final AsyncRunner asyncRunner;
+    private final CircuitBreaker<String> moodleRestCall;
+    private final int maxSize;
+    private final int pageSize;
 
-    private final Set<CourseData> preFilteredCourseIds = new HashSet<>();
+    private final Set<CourseDataShort> cachedCourseData = new HashSet<>();
 
+    private String lmsSetup = Constants.EMPTY_NOTE;
     private long lastRunTime = 0;
     private long lastLoadTime = 0;
     private boolean running = false;
 
     private long fromCutTime;
 
-    public MoodleCourseDataLazyLoader(
+    public MoodleCourseDataAsyncLoader(
             final JSONMapper jsonMapper,
-            final AsyncRunner asyncRunner) {
+            final AsyncService asyncService,
+            final AsyncRunner asyncRunner,
+            final Environment environment) {
 
         this.jsonMapper = jsonMapper;
-        this.asyncRunner = asyncRunner;
         this.fromCutTime = Utils.toUnixTimeInSeconds(DateTime.now(DateTimeZone.UTC).minusYears(3));
+        this.asyncRunner = asyncRunner;
+
+        this.moodleRestCall = asyncService.createCircuitBreaker(
+                environment.getProperty(
+                        "sebserver.webservice.circuitbreaker.moodleRestCall.attempts",
+                        Integer.class,
+                        2),
+                environment.getProperty(
+                        "sebserver.webservice.circuitbreaker.moodleRestCall.blockingTime",
+                        Long.class,
+                        Constants.SECOND_IN_MILLIS * 20),
+                environment.getProperty(
+                        "sebserver.webservice.circuitbreaker.moodleRestCall.timeToRecover",
+                        Long.class,
+                        Constants.MINUTE_IN_MILLIS));
+
+        this.maxSize =
+                environment.getProperty("sebserver.webservice.cache.moodle.course.maxSize", Integer.class, 10000);
+        this.pageSize =
+                environment.getProperty("sebserver.webservice.cache.moodle.course.pageSize", Integer.class, 500);
+    }
+
+    public void init(final String lmsSetupName) {
+        if (Constants.EMPTY_NOTE.equals(this.lmsSetup)) {
+            this.lmsSetup = lmsSetupName;
+        } else {
+            throw new IllegalStateException(
+                    "Invalid initialization of MoodleCourseDataAsyncLoader. It has already been initialized yet");
+        }
     }
 
     public long getFromCutTime() {
@@ -84,8 +118,8 @@ public class MoodleCourseDataLazyLoader {
         this.fromCutTime = fromCutTime;
     }
 
-    public Set<CourseData> getPreFilteredCourseIds() {
+    public Set<CourseDataShort> getCachedCourseData() {
-        return this.preFilteredCourseIds;
+        return new HashSet<>(this.cachedCourseData);
     }
 
     public long getLastRunTime() {
@@ -100,7 +134,7 @@ public class MoodleCourseDataLazyLoader {
         return this.lastLoadTime > 30 * Constants.SECOND_IN_MILLIS;
     }
 
-    public Set<CourseData> loadSync(final MoodleAPIRestTemplate restTemplate) {
+    public Set<CourseDataShort> loadSync(final MoodleAPIRestTemplate restTemplate) {
         if (this.running) {
             throw new IllegalStateException("Is already running asynchronously");
         }
@@ -109,9 +143,11 @@ public class MoodleCourseDataLazyLoader {
         loadAndCache(restTemplate).run();
         this.lastRunTime = Utils.getMillisecondsNow();
 
-        log.info("Loaded {} courses synchronously", this.preFilteredCourseIds.size());
+        log.info("LMS Setup: {} loaded {} courses synchronously",
+                this.lmsSetup,
+                this.cachedCourseData.size());
 
-        return this.preFilteredCourseIds;
+        return this.cachedCourseData;
     }
 
     public void loadAsync(final MoodleAPIRestTemplate restTemplate) {
@@ -126,6 +162,7 @@ public class MoodleCourseDataLazyLoader {
 
     private Runnable loadAndCache(final MoodleAPIRestTemplate restTemplate) {
         return () -> {
+            this.cachedCourseData.clear();
             final long startTime = Utils.getMillisecondsNow();
 
             loadAllQuizzes(restTemplate);
@@ -133,7 +170,9 @@ public class MoodleCourseDataLazyLoader {
             this.lastLoadTime = Utils.getMillisecondsNow() - startTime;
             this.running = false;
 
-            log.info("Loaded {} courses asynchronously", this.preFilteredCourseIds.size());
+            log.info("LMS Setup: {} loaded {} courses asynchronously",
+                    this.lmsSetup,
+                    this.cachedCourseData.size());
         };
     }
 
@@ -151,8 +190,8 @@ public class MoodleCourseDataLazyLoader {
         try {
 
             // first get courses from Moodle for page
-            final Map<String, CourseData> courseData = new HashMap<>();
+            final Map<String, CourseDataShort> courseData = new HashMap<>();
-            final Collection<CourseData> coursesPage = getCoursesPage(restTemplate, page, 1000);
+            final Collection<CourseDataShort> coursesPage = getCoursesPage(restTemplate, page, this.pageSize);
 
             if (coursesPage == null || coursesPage.isEmpty()) {
                 return false;
@@ -168,7 +207,8 @@ public class MoodleCourseDataLazyLoader {
                     MoodleCourseAccess.MOODLE_COURSE_API_COURSE_IDS,
                     new ArrayList<>(courseData.keySet()));
 
-            final String quizzesJSON = restTemplate.callMoodleAPIFunction(
+            final String quizzesJSON = callMoodleRestAPI(
+                    restTemplate,
                     MoodleCourseAccess.MOODLE_QUIZ_API_FUNCTION_NAME,
                     attributes);
 
@@ -185,28 +225,36 @@ public class MoodleCourseDataLazyLoader {
                         .stream()
                         .filter(getQuizFilter())
                         .forEach(quiz -> {
-                            final CourseData data = courseData.get(quiz.course);
+                            final CourseDataShort data = courseData.get(quiz.course);
                             if (data != null) {
                                 data.quizzes.add(quiz);
                             }
                         });
 
-                this.preFilteredCourseIds.addAll(
                 courseData.values().stream()
                         .filter(c -> !c.quizzes.isEmpty())
-                                .collect(Collectors.toList()));
+                        .forEach(c -> {
+                            if (this.cachedCourseData.size() >= this.maxSize) {
+                                log.error(
+                                        "LMS Setup: {} Cache is full and has reached its maximal size. Skip data: -> {}",
+                                        this.lmsSetup,
+                                        c);
+                            } else {
+                                this.cachedCourseData.add(c);
+                            }
+                        });
 
                 return true;
             } else {
                 return false;
             }
         } catch (final Exception e) {
-            log.error("Unexpected exception while trying to get course data: ", e);
+            log.error("LMS Setup: {} Unexpected exception while trying to get course data: ", this.lmsSetup, e);
             return false;
         }
     }
 
-    private Collection<CourseData> getCoursesPage(
+    private Collection<CourseDataShort> getCoursesPage(
             final MoodleAPIRestTemplate restTemplate,
             final int page,
             final int size) throws JsonParseException, JsonMappingException, IOException {
@@ -219,7 +267,8 @@ public class MoodleCourseDataLazyLoader {
             attributes.add(MoodleCourseAccess.MOODLE_COURSE_API_SEARCH_PAGE, String.valueOf(page));
             attributes.add(MoodleCourseAccess.MOODLE_COURSE_API_SEARCH_PAGE_SIZE, String.valueOf(size));
 
-            final String courseKeyPageJSON = restTemplate.callMoodleAPIFunction(
+            final String courseKeyPageJSON = callMoodleRestAPI(
+                    restTemplate,
                     MoodleCourseAccess.MOODLE_COURSE_SEARCH_API_FUNCTION_NAME,
                     attributes);
 
@@ -228,7 +277,9 @@ public class MoodleCourseDataLazyLoader {
                     CoursePage.class);
 
             if (keysPage == null || keysPage.courseKeys == null || keysPage.courseKeys.isEmpty()) {
-                log.info("No courses found on page: {}", page);
+                if (log.isDebugEnabled()) {
+                    log.debug("LMS Setup: {} No courses found on page: {}", this.lmsSetup, page);
+                }
                 return Collections.emptyList();
             }
 
@@ -238,7 +289,7 @@ public class MoodleCourseDataLazyLoader {
                     .map(key -> key.id)
                     .collect(Collectors.toSet());
 
-            final Collection<CourseData> result = getCoursesForIds(restTemplate, ids)
+            final Collection<CourseDataShort> result = getCoursesForIds(restTemplate, ids)
                     .stream()
                     .filter(getCourseFilter())
                     .collect(Collectors.toList());
@@ -247,19 +298,19 @@ public class MoodleCourseDataLazyLoader {
 
             return result;
         } catch (final Exception e) {
-            log.error("Unexpected error while trying to get courses page: ", e);
+            log.error("LMS Setup: {} Unexpected error while trying to get courses page: ", this.lmsSetup, e);
             return Collections.emptyList();
         }
     }
 
-    private Collection<CourseData> getCoursesForIds(
+    private Collection<CourseDataShort> getCoursesForIds(
             final MoodleAPIRestTemplate restTemplate,
             final Set<String> ids) {
 
         try {
 
             if (log.isDebugEnabled()) {
-                log.debug("Get courses for ids: {}", ids);
+                log.debug("LMS Setup: {} Get courses for ids: {}", this.lmsSetup, ids);
             }
 
             final String joinedIds = StringUtils.join(ids, Constants.COMMA);
@@ -267,32 +318,52 @@ public class MoodleCourseDataLazyLoader {
             final LinkedMultiValueMap<String, String> attributes = new LinkedMultiValueMap<>();
             attributes.add(MoodleCourseAccess.MOODLE_COURSE_API_FIELD_NAME, MoodleCourseAccess.MOODLE_COURSE_API_IDS);
             attributes.add(MoodleCourseAccess.MOODLE_COURSE_API_FIELD_VALUE, joinedIds);
-            final String coursePageJSON = restTemplate.callMoodleAPIFunction(
+            final String coursePageJSON = callMoodleRestAPI(
+                    restTemplate,
                     MoodleCourseAccess.MOODLE_COURSE_BY_FIELD_API_FUNCTION_NAME,
                     attributes);
 
-            return this.jsonMapper.<Courses> readValue(
+            return this.jsonMapper.readValue(
                     coursePageJSON,
                     Courses.class).courses;
         } catch (final Exception e) {
-            log.error("Unexpected error while trying to get courses for ids", e);
+            log.error("LMS Setup: {} Unexpected error while trying to get courses for ids", this.lmsSetup, e);
             return Collections.emptyList();
         }
     }
 
-    private Predicate<CourseQuiz> getQuizFilter() {
+    private String callMoodleRestAPI(
+            final MoodleAPIRestTemplate restTemplate,
+            final String function,
+            final MultiValueMap<String, String> queryAttributes) {
+
+        return this.moodleRestCall
+                .protectedRun(() -> restTemplate.callMoodleAPIFunction(
+                        function,
+                        queryAttributes))
+                .getOrThrow();
+
+    }
+
+    private Predicate<CourseQuizShort> getQuizFilter() {
         final long now = Utils.getSecondsNow();
         return quiz -> {
             if (quiz.time_close == null || quiz.time_close == 0 || quiz.time_close > now) {
                 return true;
             }
 
-            log.info("remove quiz {} end_time {} now {}", quiz.name, quiz.time_close, now);
+            if (log.isDebugEnabled()) {
+                log.debug("LMS Setup: {} remove quiz {} end_time {} now {}",
+                        this.lmsSetup,
+                        quiz.name,
+                        quiz.time_close,
+                        now);
+            }
             return false;
         };
     }
 
-    private Predicate<CourseData> getCourseFilter() {
+    private Predicate<CourseDataShort> getCourseFilter() {
         final long now = Utils.getSecondsNow();
         return course -> {
             if (course.start_date < this.fromCutTime) {
@@ -303,7 +374,13 @@ public class MoodleCourseDataLazyLoader {
                 return true;
             }
 
-            log.info("remove course {} end_time {} now {}", course.short_name, course.end_date, now);
+            if (log.isDebugEnabled()) {
+                log.info("LMS Setup: {} remove course {} end_time {} now {}",
+                        this.lmsSetup,
+                        course.short_name,
+                        course.end_date,
+                        now);
+            }
             return false;
         };
     }
@@ -356,77 +433,107 @@ public class MoodleCourseDataLazyLoader {
 
     }
 
-//    @JsonIgnoreProperties(ignoreUnknown = true)
+    /** Maps the Moodle course API course data */
-//    static final class CourseKeys {
+    @JsonIgnoreProperties(ignoreUnknown = true)
-//        final Collection<CourseDataKey> courses;
+    static final class CourseDataShort {
-//
+        final String id;
-//        @JsonCreator
+        final String short_name;
-//        protected CourseKeys(
+        final String idnumber;
-//                @JsonProperty(value = "courses") final Collection<CourseDataKey> courses) {
+        final Long start_date; // unix-time seconds UTC
-//            this.courses = courses;
+        final Long end_date; // unix-time seconds UTC
-//        }
+        final Long time_created; // unix-time seconds UTC
-//    }
+        final Collection<CourseQuizShort> quizzes = new ArrayList<>();
 
-//    /** Maps the Moodle course API course data */
+        @JsonCreator
-//    @JsonIgnoreProperties(ignoreUnknown = true)
+        protected CourseDataShort(
-//    static final class CourseDataKey {
+                @JsonProperty(value = "id") final String id,
-//        final String id;
+                @JsonProperty(value = "shortname") final String short_name,
-//        final String short_name;
+                @JsonProperty(value = "idnumber") final String idnumber,
-//        final Long start_date; // unix-time seconds UTC
+                @JsonProperty(value = "startdate") final Long start_date,
-//        final Long end_date; // unix-time seconds UTC
+                @JsonProperty(value = "enddate") final Long end_date,
-//        final Long time_created; // unix-time seconds UTC
+                @JsonProperty(value = "timecreated") final Long time_created) {
-//        final Collection<CourseQuizKey> quizzes = new ArrayList<>();
-//
-//        @JsonCreator
-//        protected CourseDataKey(
-//                @JsonProperty(value = "id") final String id,
-//                @JsonProperty(value = "shortname") final String short_name,
-//                @JsonProperty(value = "startdate") final Long start_date,
-//                @JsonProperty(value = "enddate") final Long end_date,
-//                @JsonProperty(value = "timecreated") final Long time_created) {
-//
-//            this.id = id;
-//            this.short_name = short_name;
-//            this.start_date = start_date;
-//            this.end_date = end_date;
-//            this.time_created = time_created;
-//        }
-//
-//    }
 
-//    @JsonIgnoreProperties(ignoreUnknown = true)
+            this.id = id;
-//    static final class CourseQuizKeys {
+            this.short_name = short_name;
-//        final Collection<CourseQuizKey> quizzes;
+            this.idnumber = idnumber;
-//
+            this.start_date = start_date;
-//        @JsonCreator
+            this.end_date = end_date;
-//        protected CourseQuizKeys(
+            this.time_created = time_created;
-//                @JsonProperty(value = "quizzes") final Collection<CourseQuizKey> quizzes) {
+        }
-//            this.quizzes = quizzes;
+
-//        }
+        @Override
-//    }
+        public int hashCode() {
-//
+            final int prime = 31;
-//    @JsonIgnoreProperties(ignoreUnknown = true)
+            int result = 1;
-//    static final class CourseQuizKey {
+            result = prime * result + ((this.id == null) ? 0 : this.id.hashCode());
-//        final String id;
+            return result;
-//        final String course;
+        }
-//        final String name;
+
-//        final Long time_open; // unix-time seconds UTC
+        @Override
-//        final Long time_close; // unix-time seconds UTC
+        public boolean equals(final Object obj) {
-//
+            if (this == obj)
-//        @JsonCreator
+                return true;
-//        protected CourseQuizKey(
+            if (obj == null)
-//                @JsonProperty(value = "id") final String id,
+                return false;
-//                @JsonProperty(value = "course") final String course,
+            if (getClass() != obj.getClass())
-//                @JsonProperty(value = "name") final String name,
+                return false;
-//                @JsonProperty(value = "timeopen") final Long time_open,
+            final CourseDataShort other = (CourseDataShort) obj;
-//                @JsonProperty(value = "timeclose") final Long time_close) {
+            if (this.id == null) {
-//
+                if (other.id != null)
-//            this.id = id;
+                    return false;
-//            this.course = course;
+            } else if (!this.id.equals(other.id))
-//            this.name = name;
+                return false;
-//            this.time_open = time_open;
+            return true;
-//            this.time_close = time_close;
+        }
-//        }
+    }
-//    }
+
+    @JsonIgnoreProperties(ignoreUnknown = true)
+    private static final class Courses {
+        final Collection<CourseDataShort> courses;
+
+        @JsonCreator
+        protected Courses(
+                @JsonProperty(value = "courses") final Collection<CourseDataShort> courses) {
+            this.courses = courses;
+        }
+    }
+
+    @JsonIgnoreProperties(ignoreUnknown = true)
+    static final class CourseQuizData {
+        final Collection<CourseQuizShort> quizzes;
+
+        @JsonCreator
+        protected CourseQuizData(
+                @JsonProperty(value = "quizzes") final Collection<CourseQuizShort> quizzes) {
+            this.quizzes = quizzes;
+        }
+    }
+
+    @JsonIgnoreProperties(ignoreUnknown = true)
+    static final class CourseQuizShort {
+        final String id;
+        final String course;
+        final String course_module;
+        final String name;
+        final Long time_open; // unix-time seconds UTC
+        final Long time_close; // unix-time seconds UTC
+
+        @JsonCreator
+        protected CourseQuizShort(
+                @JsonProperty(value = "id") final String id,
+                @JsonProperty(value = "course") final String course,
+                @JsonProperty(value = "coursemodule") final String course_module,
+                @JsonProperty(value = "name") final String name,
+                @JsonProperty(value = "timeopen") final Long time_open,
+                @JsonProperty(value = "timeclose") final Long time_close) {
+
+            this.id = id;
+            this.course = course;
+            this.course_module = course_module;
+            this.name = name;
+            this.time_open = time_open;
+            this.time_close = time_close;
+        }
+    }
 
 }

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

@@ -12,6 +12,7 @@ import org.apache.commons.lang3.StringUtils;
 import org.springframework.beans.factory.annotation.Value;
 import org.springframework.context.ApplicationContext;
 import org.springframework.context.annotation.Lazy;
+import org.springframework.core.env.Environment;
 import org.springframework.stereotype.Service;
 
 import ch.ethz.seb.sebserver.ClientHttpRequestFactoryService;
@@ -32,6 +33,7 @@ public class MoodleLmsAPITemplateFactory {
 
     private final JSONMapper jsonMapper;
     private final AsyncService asyncService;
+    private final Environment environment;
     private final ClientCredentialService clientCredentialService;
     private final ClientHttpRequestFactoryService clientHttpRequestFactoryService;
     private final ApplicationContext applicationContext;
@@ -40,6 +42,7 @@ public class MoodleLmsAPITemplateFactory {
     protected MoodleLmsAPITemplateFactory(
             final JSONMapper jsonMapper,
             final AsyncService asyncService,
+            final Environment environment,
             final ClientCredentialService clientCredentialService,
             final ClientHttpRequestFactoryService clientHttpRequestFactoryService,
             final ApplicationContext applicationContext,
@@ -47,6 +50,7 @@ public class MoodleLmsAPITemplateFactory {
 
         this.jsonMapper = jsonMapper;
         this.asyncService = asyncService;
+        this.environment = environment;
         this.clientCredentialService = clientCredentialService;
         this.clientHttpRequestFactoryService = clientHttpRequestFactoryService;
         this.applicationContext = applicationContext;
@@ -62,8 +66,9 @@ public class MoodleLmsAPITemplateFactory {
 
         return Result.tryCatch(() -> {
 
-            final MoodleCourseDataLazyLoader lazyLoaderPrototype =
+            final MoodleCourseDataAsyncLoader asyncLoaderPrototype =
-                    this.applicationContext.getBean(MoodleCourseDataLazyLoader.class);
+                    this.applicationContext.getBean(MoodleCourseDataAsyncLoader.class);
+            asyncLoaderPrototype.init(lmsSetup.name);
 
             final MoodleRestTemplateFactory moodleRestTemplateFactory = new MoodleRestTemplateFactory(
                     this.jsonMapper,
@@ -78,8 +83,9 @@ public class MoodleLmsAPITemplateFactory {
                     this.jsonMapper,
                     lmsSetup,
                     moodleRestTemplateFactory,
-                    lazyLoaderPrototype,
+                    asyncLoaderPrototype,
-                    this.asyncService);
+                    this.asyncService,
+                    this.environment);
 
             final MoodleCourseRestriction moodleCourseRestriction = new MoodleCourseRestriction(
                     this.jsonMapper,

src/main/java/ch/ethz/seb/sebserver/webservice/servicelayer/session/impl/SEBClientConnectionServiceImpl.java

@@ -489,9 +489,7 @@ public class SEBClientConnectionServiceImpl implements SEBClientConnectionServic
                     .filter(Objects::nonNull)
                     .filter(connection -> connection.pingIndicator != null &&
                             connection.clientConnection.status.establishedStatus)
-                    .map(connection -> connection.pingIndicator.updateLogEvent())
+                    .forEach(connection -> connection.pingIndicator.updateLogEvent());
-                    .filter(Objects::nonNull)
-                    .forEach(this.eventHandlingStrategy);
 
         } catch (final Exception e) {
             log.error("Failed to update ping events: ", e);

src/main/java/ch/ethz/seb/sebserver/webservice/servicelayer/session/impl/SEBClientNotificationServiceImpl.java

@@ -42,7 +42,7 @@ public class SEBClientNotificationServiceImpl implements SEBClientNotificationSe
 
     private final ClientEventDAO clientEventDAO;
     private final SEBClientInstructionService sebClientInstructionService;
-    private final Set<Long> pendingNotifications;
+    private final Set<Long> pendingNotifications = new HashSet<>();
 
     public SEBClientNotificationServiceImpl(
             final ClientEventDAO clientEventDAO,
@@ -50,19 +50,25 @@ public class SEBClientNotificationServiceImpl implements SEBClientNotificationSe
 
         this.clientEventDAO = clientEventDAO;
         this.sebClientInstructionService = sebClientInstructionService;
-        this.pendingNotifications = new HashSet<>();
     }
 
     @Override
     public Boolean hasAnyPendingNotification(final Long clientConnectionId) {
-        if (this.pendingNotifications.contains(clientConnectionId)) {
+
+        if (this.pendingNotifications.add(clientConnectionId)) {
             return true;
         }
 
         final boolean hasAnyPendingNotification = !getPendingNotifications(clientConnectionId)
                 .getOr(Collections.emptyList())
                 .isEmpty();
+
         if (hasAnyPendingNotification) {
+            // NOTE this is a quick and dirty way to keep cache pendingNotifications cache size short.
+            // TODO find a better way to do this.
+            if (this.pendingNotifications.size() > 100) {
+                this.pendingNotifications.clear();
+            }
             this.pendingNotifications.add(clientConnectionId);
         }
 

src/main/resources/config/application-dev-ws.properties

@@ -1,8 +1,6 @@
 server.address=localhost
 server.port=8090
 
-#logging.file=log/sebserver.log
-
 # data source configuration
 spring.datasource.initialize=true
 spring.datasource.initialization-mode=always

src/main/resources/config/application-dev.properties

@@ -6,6 +6,8 @@ server.servlet.context-path=/
 server.tomcat.uri-encoding=UTF-8
 
 logging.level.ch=INFO
+logging.level.org.springframework.cache=INFO
+logging.level.ch.ethz.seb.sebserver.webservice.servicelayer.lms.impl=DEBUG
 
 sebserver.http.client.connect-timeout=150000
 sebserver.http.client.connection-request-timeout=100000

src/main/resources/config/application-ws.properties

@@ -8,6 +8,10 @@ sebserver.init.adminaccount.gen-on-init=true
 sebserver.init.organisation.name=SEB Server
 sebserver.init.adminaccount.username=sebserver-admin
 
+### webservice caching
+spring.cache.jcache.provider=org.ehcache.jsr107.EhcacheCachingProvider
+spring.cache.jcache.config=classpath:config/ehcache.xml
+
 ### webservice data source configuration
 spring.datasource.username=root
 spring.datasource.initialize=true

src/main/resources/config/application.properties

@@ -13,7 +13,7 @@ server.port=8080
 server.servlet.context-path=/
 
 # Tomcat
-server.tomcat.max-threads=1000
+server.tomcat.max-threads=2000
 server.tomcat.accept-count=300
 server.tomcat.uri-encoding=UTF-8
 

src/main/resources/config/ehcache.xml

@@ -0,0 +1,85 @@
+<config xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+    xmlns="http://www.ehcache.org/v3"
+    xmlns:jsr107="http://www.ehcache.org/v3/jsr107"
+    xsi:schemaLocation="
+            http://www.ehcache.org/v3 http://www.ehcache.org/schema/ehcache-core-3.0.xsd
+            http://www.ehcache.org/v3/jsr107 http://www.ehcache.org/schema/ehcache-107-ext-3.0.xsd">
+
+    <cache alias="RUNNING_EXAM">
+        <key-type>java.lang.Long</key-type>
+        <value-type>ch.ethz.seb.sebserver.gbl.model.exam.Exam</value-type>
+        <expiry>
+            <tti unit="hours">24</tti>
+        </expiry>
+        <resources>
+            <heap unit="entries">100</heap>
+        </resources>
+    </cache>
+    
+    <cache alias="ACTIVE_CLIENT_CONNECTION">
+        <key-type>java.lang.String</key-type>
+        <value-type>ch.ethz.seb.sebserver.webservice.servicelayer.session.impl.ClientConnectionDataInternal</value-type>
+        <expiry>
+            <tti unit="hours">24</tti>
+        </expiry>
+        <resources>
+            <heap unit="entries">2000</heap>
+        </resources>
+    </cache>
+    
+    <cache alias="SEB_CONFIG_EXAM">
+        <key-type>java.lang.Long</key-type>
+        <value-type>ch.ethz.seb.sebserver.webservice.servicelayer.session.impl.InMemorySEBConfig</value-type>
+        <expiry>
+            <tti unit="hours">24</tti>
+        </expiry>
+        <resources>
+            <heap unit="entries">20</heap>
+        </resources>
+    </cache>
+    
+    <cache alias="CACHE_NAME_PING_RECORD">
+        <key-type>java.lang.String</key-type>
+        <value-type>ch.ethz.seb.sebserver.webservice.datalayer.batis.model.ClientEventRecord</value-type>
+        <expiry>
+            <tti unit="hours">24</tti>
+        </expiry>
+        <resources>
+            <heap unit="entries">2000</heap>
+        </resources>
+    </cache>
+    
+    <cache alias="CONNECTION_TOKENS_CACHE">
+        <key-type>java.lang.Long</key-type>
+        <value-type>ch.ethz.seb.sebserver.gbl.util.Result</value-type>
+        <expiry>
+            <tti unit="hours">24</tti>
+        </expiry>
+        <resources>
+            <heap unit="entries">100</heap>
+        </resources>
+    </cache>
+    
+    <cache alias="ACCESS_TOKEN_STORE_CACHE">
+        <key-type>org.springframework.security.oauth2.common.OAuth2AccessToken</key-type>
+        <value-type>org.springframework.security.oauth2.provider.OAuth2Authentication</value-type>
+        <expiry>
+            <tti unit="hours">24</tti>
+        </expiry>
+        <resources>
+            <heap unit="entries">100</heap>
+        </resources>
+    </cache>
+    
+    <cache alias="EXAM_CLIENT_DETAILS_CACHE">
+        <key-type>java.lang.String</key-type>
+        <value-type>ch.ethz.seb.sebserver.gbl.util.Result</value-type>
+        <expiry>
+            <tti unit="hours">24</tti>
+        </expiry>
+        <resources>
+            <heap unit="entries">2000</heap>
+        </resources>
+    </cache>
+    
+</config>

src/main/resources/logback-spring.xml

@@ -19,6 +19,7 @@
 
     <root level="DEBUG" additivity="true">
       <appender-ref ref="STDOUT" />
+      <appender-ref ref="FILE" />
     </root>
     <Logger name="ch.ethz.seb.SEB_SERVER_INIT" level="INFO" additivity="false">
         <appender-ref ref="STDOUT" />

src/test/java/ch/ethz/seb/sebserver/webservice/servicelayer/lms/impl/moodle/MoodleCourseAccessTest.java

@@ -15,6 +15,9 @@ import static org.mockito.Mockito.*;
 import java.util.TreeMap;
 
 import org.junit.Test;
+import org.mockito.Mock;
+import org.springframework.core.env.Environment;
+import org.springframework.mock.env.MockEnvironment;
 import org.springframework.util.LinkedMultiValueMap;
 import org.springframework.util.MultiValueMap;
 
@@ -28,6 +31,9 @@ import ch.ethz.seb.sebserver.webservice.servicelayer.lms.impl.moodle.MoodleRestT
 
 public class MoodleCourseAccessTest {
 
+    @Mock
+    Environment env = new MockEnvironment();
+
     @Test
     public void testGetExamineeAccountDetails() {
 
@@ -68,7 +74,8 @@ public class MoodleCourseAccessTest {
                 null,
                 moodleRestTemplateFactory,
                 null,
-                mock(AsyncService.class));
+                mock(AsyncService.class),
+                this.env);
 
         final String examId = "123";
         final Result<ExamineeAccountDetails> examineeAccountDetails =
@@ -116,7 +123,8 @@ public class MoodleCourseAccessTest {
                 null,
                 moodleRestTemplateFactory,
                 null,
-                mock(AsyncService.class));
+                mock(AsyncService.class),
+                this.env);
 
         final LmsSetupTestResult initAPIAccess = moodleCourseAccess.initAPIAccess();
         assertNotNull(initAPIAccess);
@@ -138,7 +146,8 @@ public class MoodleCourseAccessTest {
                 null,
                 moodleRestTemplateFactory,
                 null,
-                mock(AsyncService.class));
+                mock(AsyncService.class),
+                this.env);
 
         final LmsSetupTestResult initAPIAccess = moodleCourseAccess.initAPIAccess();
         assertNotNull(initAPIAccess);
@@ -159,7 +168,8 @@ public class MoodleCourseAccessTest {
                 null,
                 moodleRestTemplateFactory,
                 null,
-                mock(AsyncService.class));
+                mock(AsyncService.class),
+                this.env);
 
         final LmsSetupTestResult initAPIAccess = moodleCourseAccess.initAPIAccess();
         assertNotNull(initAPIAccess);

src/test/resources/application-test.properties

@@ -12,6 +12,9 @@ server.servlet.context-path=/
 spring.main.allow-bean-definition-overriding=true
 sebserver.password=test-password
 
+spring.cache.jcache.provider=
+spring.cache.jcache.config=classpath:config/ehcache.xml
+
 spring.h2.console.enabled=true
 spring.datasource.platform=h2
 spring.datasource.url=jdbc:h2:mem:test;MODE=MySQL;DB_CLOSE_DELAY=-1;DB_CLOSE_ON_EXIT=FALSE