diff --git a/headless-services/spring-boot-language-server/src/main/java/org/springframework/ide/vscode/boot/app/BootLanguageServerBootApp.java b/headless-services/spring-boot-language-server/src/main/java/org/springframework/ide/vscode/boot/app/BootLanguageServerBootApp.java
index 759184d766..ad88033b5b 100644
--- a/headless-services/spring-boot-language-server/src/main/java/org/springframework/ide/vscode/boot/app/BootLanguageServerBootApp.java
+++ b/headless-services/spring-boot-language-server/src/main/java/org/springframework/ide/vscode/boot/app/BootLanguageServerBootApp.java
@@ -42,7 +42,7 @@
 import org.springframework.ide.vscode.boot.common.RelaxedNameConfig;
 import org.springframework.ide.vscode.boot.index.SpringMetamodelIndex;
 import org.springframework.ide.vscode.boot.index.cache.IndexCache;
-import org.springframework.ide.vscode.boot.index.cache.IndexCacheOnDisc;
+import org.springframework.ide.vscode.boot.index.cache.IndexCacheOnDiscDeltaBased;
 import org.springframework.ide.vscode.boot.index.cache.IndexCacheVoid;
 import org.springframework.ide.vscode.boot.java.JavaDefinitionHandler;
 import org.springframework.ide.vscode.boot.java.beans.DependsOnDefinitionProvider;
@@ -150,7 +150,7 @@ public static void main(String[] args) throws Exception {
 	@Bean
 	IndexCache symbolCache(BootLsConfigProperties props) {
 		if (props.isSymbolCacheEnabled()) {
-			return new IndexCacheOnDisc(new File(props.getSymbolCacheDir()));
+			return new IndexCacheOnDiscDeltaBased(new File(props.getSymbolCacheDir()));
 		} else {
 			return new IndexCacheVoid();
 		}
diff --git a/headless-services/spring-boot-language-server/src/main/java/org/springframework/ide/vscode/boot/index/cache/IndexCacheOnDiscDeltaBased.java b/headless-services/spring-boot-language-server/src/main/java/org/springframework/ide/vscode/boot/index/cache/IndexCacheOnDiscDeltaBased.java
index fb94bc082e..12d02ae5c2 100644
--- a/headless-services/spring-boot-language-server/src/main/java/org/springframework/ide/vscode/boot/index/cache/IndexCacheOnDiscDeltaBased.java
+++ b/headless-services/spring-boot-language-server/src/main/java/org/springframework/ide/vscode/boot/index/cache/IndexCacheOnDiscDeltaBased.java
@@ -292,6 +292,8 @@ private boolean isFileMatch(SortedMap<String, Long> files1, SortedMap<String, Lo
 	
 	private <T extends IndexCacheable> void compact(IndexCacheKey cacheKey, Class<T> type) {
 		if (this.compactingCounter.get(cacheKey) > this.compactingCounterBoundary) {
+			log.info("compacting...");
+			
 			IndexCacheStore<T> compactedData = retrieveStoreFromIncrementalStorage(cacheKey, type).getLeft();
 			persist(cacheKey, new DeltaSnapshot<T>(compactedData), false);
 			this.compactingCounter.put(cacheKey, 0);
diff --git a/headless-services/spring-boot-language-server/src/main/java/org/springframework/ide/vscode/boot/java/utils/SpringFactoriesIndexer.java b/headless-services/spring-boot-language-server/src/main/java/org/springframework/ide/vscode/boot/java/utils/SpringFactoriesIndexer.java
index 0be39ac6e8..84118bcf8e 100644
--- a/headless-services/spring-boot-language-server/src/main/java/org/springframework/ide/vscode/boot/java/utils/SpringFactoriesIndexer.java
+++ b/headless-services/spring-boot-language-server/src/main/java/org/springframework/ide/vscode/boot/java/utils/SpringFactoriesIndexer.java
@@ -60,7 +60,7 @@ public class SpringFactoriesIndexer implements SpringIndexer {
 	
 	// whenever the implementation of the indexer changes in a way that the stored data in the cache is no longer valid,
 	// we need to change the generation - this will result in a re-indexing due to no up-to-date cache data being found
-	private static final String GENERATION = "GEN-6";
+	private static final String GENERATION = "GEN-7";
 	
 	private static final String FILE_PATTERN = "**/META-INF/spring/*.factories";
 	
diff --git a/headless-services/spring-boot-language-server/src/main/java/org/springframework/ide/vscode/boot/java/utils/SpringIndexerJava.java b/headless-services/spring-boot-language-server/src/main/java/org/springframework/ide/vscode/boot/java/utils/SpringIndexerJava.java
index 3e1aabaa28..07d2c54971 100644
--- a/headless-services/spring-boot-language-server/src/main/java/org/springframework/ide/vscode/boot/java/utils/SpringIndexerJava.java
+++ b/headless-services/spring-boot-language-server/src/main/java/org/springframework/ide/vscode/boot/java/utils/SpringIndexerJava.java
@@ -93,7 +93,7 @@ public static enum SCAN_PASS {
 
 	// whenever the implementation of the indexer changes in a way that the stored data in the cache is no longer valid,
 	// we need to change the generation - this will result in a re-indexing due to no up-to-date cache data being found
-	private static final String GENERATION = "GEN-7";
+	private static final String GENERATION = "GEN-8";
 	private static final String INDEX_FILES_TASK_ID = "index-java-source-files-task-";
 
 	private static final String SYMBOL_KEY = "symbols";
diff --git a/headless-services/spring-boot-language-server/src/main/java/org/springframework/ide/vscode/boot/java/utils/SpringIndexerXML.java b/headless-services/spring-boot-language-server/src/main/java/org/springframework/ide/vscode/boot/java/utils/SpringIndexerXML.java
index 10a4428c6c..798dc11c7f 100644
--- a/headless-services/spring-boot-language-server/src/main/java/org/springframework/ide/vscode/boot/java/utils/SpringIndexerXML.java
+++ b/headless-services/spring-boot-language-server/src/main/java/org/springframework/ide/vscode/boot/java/utils/SpringIndexerXML.java
@@ -54,7 +54,7 @@ public class SpringIndexerXML implements SpringIndexer {
 	
 	// whenever the implementation of the indexer changes in a way that the stored data in the cache is no longer valid,
 	// we need to change the generation - this will result in a re-indexing due to no up-to-date cache data being found
-	private static final String GENERATION = "GEN-5";
+	private static final String GENERATION = "GEN-6";
 
 	private static final String SYMBOL_KEY = "symbols";
 	private static final String BEANS_KEY = "beans";