Handling boot time elastic search connect exception more robust

src/main/java/at/ac/uibk/gitsearch/config/ElasticsearchConfiguration.java

@@ -189,7 +189,7 @@ public class ElasticsearchConfiguration extends ElasticsearchConfigurationSuppor
     }
 
     @Bean
-    public ElasticsearchClient getElasticsearchAPIClient() throws MalformedURLException {
+    ElasticsearchClient getElasticsearchAPIClient() throws MalformedURLException {
         // Create the transport with a Jackson mapper
         final JacksonJsonpMapper mapper = new JacksonJsonpMapper();
 

src/main/java/at/ac/uibk/gitsearch/repository/search/MetaDataRepository.java

@@ -46,6 +46,7 @@ import java.util.Spliterators;
 import java.util.StringTokenizer;
 import java.util.TreeMap;
 import java.util.concurrent.ConcurrentHashMap;
+import java.util.concurrent.Executor;
 import java.util.concurrent.atomic.AtomicBoolean;
 import java.util.concurrent.atomic.AtomicInteger;
 import java.util.function.Consumer;
@@ -55,6 +56,7 @@ import java.util.stream.Collectors;
 import java.util.stream.Stream;
 import java.util.stream.StreamSupport;
 import javax.annotation.PostConstruct;
+import javax.inject.Named;
 import javax.ws.rs.NotFoundException;
 import org.apache.commons.lang3.StringUtils;
 import org.apache.logging.log4j.LogManager;
@@ -110,6 +112,10 @@ public class MetaDataRepository {
     @Autowired
     private StatisticsRepository statisticsRepository;
 
+    @Autowired
+    @Named("taskExecutor")
+    private Executor asyncExecutor;
+
     /**
      * contains for each Field, a list of Strings mapped to a completion. Together
      * with hit counts E.g. "metadata.creator" -> Kerstin -> {"Kerstin Limbeck" ->
@@ -254,6 +260,25 @@ public class MetaDataRepository {
 
     @Scheduled(cron = "0 */10 * * * ?") // should run every 10 minutes
     @PostConstruct
+    public void triggerUpdateAutocompletionCache() {
+        Runnable tryUpdate = () -> {
+            for (int i = 0; i < 10; i++) {
+                try {
+                    updateAutocompletionCache();
+                    return;
+                } catch (IOException e) {
+                    LOGGER.info("Connect for update failed: {}. Retrying {}", e, i);
+                    try {
+                        Thread.sleep(2000L);
+                    } catch (InterruptedException e1) {
+                        LOGGER.info("Someone interupted  update : {}. Retrying {}", e1, i);
+                    }
+                }
+            }
+        };
+        asyncExecutor.execute(tryUpdate);
+    }
+
     public void updateAutocompletionCache() throws IOException {
         synchronized (this) {
             Map<String, Map<String, Map<String, Integer>>> reloadedCachedCompletions = new ConcurrentHashMap<>();
@@ -306,7 +331,10 @@ public class MetaDataRepository {
                     });
 
                 cachedCompletions = reloadedCachedCompletions;
-            } catch (co.elastic.clients.elasticsearch._types.ElasticsearchException | ElasticsearchException | ConnectException ex) {
+            } catch (ConnectException e) {
+                // just rethrow silently
+                throw e;
+            } catch (co.elastic.clients.elasticsearch._types.ElasticsearchException | ElasticsearchException ex) {
                 // this may happen mainly during testing, when
                 // test elasticsearch server is not setup correctly
                 LOGGER.error("Cannot update completion Cache", ex);

src/main/java/at/ac/uibk/gitsearch/service/MonitoringService.java

@@ -6,6 +6,7 @@ import io.micrometer.core.instrument.Metrics;
 import io.micrometer.core.instrument.Tag;
 import io.micrometer.core.instrument.Tags;
 import java.io.IOException;
+import java.net.ConnectException;
 import java.util.Arrays;
 import java.util.List;
 import java.util.Map;
@@ -118,14 +119,17 @@ public class MonitoringService {
         AtomicInteger exerciseCounter = new AtomicInteger(0);
         try {
             Map<String, Integer> languageCount = new ConcurrentHashMap<>();
-            final Stream<SearchResultDTO> searchResults = this.getAllSearchResults();
+            try {
+                final Stream<SearchResultDTO> searchResults = this.getAllSearchResults();
 
-            searchResults.forEach(exercise -> {
-                exerciseCounter.addAndGet(1);
-                updateLanguageCount(exercise, languageCount);
-            });
-
-            this.setExercisesLanguageCount(languageCount);
+                searchResults.forEach(exercise -> {
+                    exerciseCounter.addAndGet(1);
+                    updateLanguageCount(exercise, languageCount);
+                });
+                this.setExercisesLanguageCount(languageCount);
+            } catch (ConnectException e) {
+                LOGGER.warn("An Connection Exception occurred {}", e.getMessage());
+            }
         } catch (IOException | ElasticsearchException exception) {
             LOGGER.warn("An IOException occurred", exception);
             return;