diff --git a/data-store/src/main/java/org/lucares/pdb/datastore/internal/FolderStorage.java b/data-store/src/main/java/org/lucares/pdb/datastore/internal/FolderStorage.java
index e937b79..34a0899 100644
--- a/data-store/src/main/java/org/lucares/pdb/datastore/internal/FolderStorage.java
+++ b/data-store/src/main/java/org/lucares/pdb/datastore/internal/FolderStorage.java
@@ -45,11 +45,11 @@ public class FolderStorage {
 
 		ensureCapacity();
 
-		String filename = filenamePrefix + filenameSuffix;
+		String filename = filenamePrefix + "$" + filenameSuffix;
 		int index = 1;
 		Path newFile = currentDirectory.resolve(filename);
 		while (Files.exists(newFile)) {
-			filename = filenamePrefix + index++ + filenameSuffix;
+			filename = filenamePrefix + "$" + index++ + filenameSuffix;
 			newFile = currentDirectory.resolve(filename);
 		}
 		Files.createFile(newFile);
diff --git a/pdb-ui/src/main/java/org/lucares/pdbui/TcpIngestor.java b/pdb-ui/src/main/java/org/lucares/pdbui/TcpIngestor.java
index 5a0d9c7..b5aee92 100644
--- a/pdb-ui/src/main/java/org/lucares/pdbui/TcpIngestor.java
+++ b/pdb-ui/src/main/java/org/lucares/pdbui/TcpIngestor.java
@@ -142,7 +142,7 @@ public class TcpIngestor implements Ingestor, AutoCloseable, DisposableBean {
 				default:
 					if (value instanceof String) {
 						tags.add(key, (String) value);
-					} else {
+					} else if (value != null) {
 						tags.add(key, String.valueOf(value));
 					}
 					break;
diff --git a/performanceDb/src/main/java/org/lucares/performance/db/PerformanceDb.java b/performanceDb/src/main/java/org/lucares/performance/db/PerformanceDb.java
index 064f100..fa53c11 100644
--- a/performanceDb/src/main/java/org/lucares/performance/db/PerformanceDb.java
+++ b/performanceDb/src/main/java/org/lucares/performance/db/PerformanceDb.java
@@ -63,7 +63,7 @@ public class PerformanceDb implements AutoCloseable {
 
 	public void put(final BlockingIterator<Entry> entries) throws WriteException {
 
-		final Duration timeBetweenSyncs = Duration.ofSeconds(1);
+		final Duration timeBetweenSyncs = Duration.ofSeconds(10);
 		long count = 0;
 		long insertionsSinceLastSync = 0;