diff --git a/performanceDb/src/main/java/org/lucares/performance/db/TagsToFile.java b/performanceDb/src/main/java/org/lucares/performance/db/TagsToFile.java
index a8749c8..ae96346 100644
--- a/performanceDb/src/main/java/org/lucares/performance/db/TagsToFile.java
+++ b/performanceDb/src/main/java/org/lucares/performance/db/TagsToFile.java
@@ -26,6 +26,7 @@ import org.slf4j.LoggerFactory;
 public class TagsToFile implements AutoCloseable {
 
 	private static final Logger LOGGER = LoggerFactory.getLogger(TagsToFile.class);
+	private final static Logger METRICS_LOGGER = LoggerFactory.getLogger("org.lucares.metrics.ingestion.tagsToFile");
 
 	private static class WriterCache {
 		final List<PdbWriter> writers = new ArrayList<>();
@@ -93,6 +94,7 @@ public class TagsToFile implements AutoCloseable {
 			result = optionalWriter.get();
 			LOGGER.trace("using existing pdbWriter: {}", result);
 		} else {
+			final long start = System.nanoTime();
 			final List<PdbFile> pdbFiles = getFilesMatchingTagsExactly(tags);
 
 			assertAllFilesHaveSameFolder(pdbFiles);
@@ -102,6 +104,9 @@ public class TagsToFile implements AutoCloseable {
 			final List<Optional<PdbWriter>> existingWriters = CollectionUtils.filter(optionalWriters,
 					Optional::isPresent);
 			final List<PdbWriter> writers = CollectionUtils.map(existingWriters, Optional::get);
+			
+			METRICS_LOGGER.debug("find writers took {}ms for tags {}", (System.nanoTime() - start)
+					/ 1_000_000.0, tags);
 
 			final Optional<PdbWriter> optionalFirst = chooseBestMatchingWriter(writers, date);