Closes #62: logs for index checking, explicit commit on close

docs-core/pom.xml

@@ -93,6 +93,12 @@
       <artifactId>lucene-queryparser</artifactId>
     </dependency>
     
+    <!-- Only there to read old index and rebuild them -->
+    <dependency>
+      <groupId>org.apache.lucene</groupId>
+      <artifactId>lucene-backward-codecs</artifactId>
+    </dependency>
+    
     <dependency>
       <groupId>org.imgscalr</groupId>
       <artifactId>imgscalr-lib</artifactId>

docs-core/src/main/java/com/sismics/docs/core/service/IndexingService.java

@@ -9,9 +9,9 @@ import org.apache.lucene.index.CheckIndex.Status;
 import org.apache.lucene.index.CheckIndex.Status.SegmentInfoStatus;
 import org.apache.lucene.index.DirectoryReader;
 import org.apache.lucene.store.Directory;
+import org.apache.lucene.store.NoLockFactory;
 import org.apache.lucene.store.RAMDirectory;
 import org.apache.lucene.store.SimpleFSDirectory;
-import org.apache.lucene.store.SingleInstanceLockFactory;
 import org.apache.lucene.util.Version;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
@@ -63,29 +63,35 @@ public class IndexingService extends AbstractScheduledService {
             Path luceneDirectory = DirectoryUtil.getLuceneDirectory();
             log.info("Using file Lucene storage: {}", luceneDirectory);
             try {
-                directory = new SimpleFSDirectory(luceneDirectory, new SingleInstanceLockFactory());
+                directory = new SimpleFSDirectory(luceneDirectory, NoLockFactory.INSTANCE);
             } catch (IOException e) {
                 log.error("Error initializing Lucene index", e);
             }
         }
         
         // Check index version and rebuild it if necessary
+        try {
+            if (DirectoryReader.indexExists(directory)) {
                 log.info("Checking index health and version");
                 try (CheckIndex checkIndex = new CheckIndex(directory)) {
                     Status status = checkIndex.checkIndex();
                     if (status.clean) {
                         for (SegmentInfoStatus segmentInfo : status.segmentInfos) {
                             if (!segmentInfo.version.onOrAfter(Version.LATEST)) {
+                                log.info("Index is old (" + segmentInfo.version + "), rebuilding");
                                 RebuildIndexAsyncEvent rebuildIndexAsyncEvent = new RebuildIndexAsyncEvent();
                                 AppContext.getInstance().getAsyncEventBus().post(rebuildIndexAsyncEvent);
                                 break;
                             }
                         }
                     } else {
+                        log.info("Index is dirty, rebuilding");
                         RebuildIndexAsyncEvent rebuildIndexAsyncEvent = new RebuildIndexAsyncEvent();
                         AppContext.getInstance().getAsyncEventBus().post(rebuildIndexAsyncEvent);
                     }
-        } catch (IOException e) {
+                }
+            }
+        } catch (Exception e) {
             log.error("Error checking index", e);
         }
     }

docs-core/src/main/java/com/sismics/docs/core/util/LuceneUtil.java

@@ -33,6 +33,9 @@ public class LuceneUtil {
         // Standard analyzer
         IndexWriterConfig config = new IndexWriterConfig(new StandardAnalyzer());
         
+        // Automatically commit when closing this writer
+        config.setCommitOnClose(true);
+        
         // Merge sequentially, because Lucene writing is already done asynchronously 
         config.setMergeScheduler(new SerialMergeScheduler());
         
@@ -59,7 +62,7 @@ public class LuceneUtil {
         try {
             indexWriter.close();
         } catch (IOException e) {
-            log.error("Cannot close IndexWriter", e);
+            log.error("Cannot commit and close IndexWriter", e);
         }
     }
     

docs-parent/pom.xml

@@ -339,6 +339,12 @@
         <version>${org.apache.lucene.version}</version>
       </dependency>
       
+      <dependency>
+        <groupId>org.apache.lucene</groupId>
+        <artifactId>lucene-backward-codecs</artifactId>
+        <version>${org.apache.lucene.version}</version>
+      </dependency>
+      
       <dependency>
         <groupId>org.imgscalr</groupId>
         <artifactId>imgscalr-lib</artifactId>