do not create a new ObjectMapper per entry

also read value with MappingIterator.
This made reading 20-30 times faster. 
We can now read and index 100k-500k per second.
The varianz might be due to LuDB slowness.

performanceDb/src/main/java/org/lucares/performance/db/PerformanceDb.java

@@ -91,7 +91,7 @@ public class PerformanceDb implements AutoCloseable {
 				writer.write(entry);
 				count++;
 
-				if (count == 10000) {
+				if (count == 100000) {
 					final long end = System.nanoTime();
 					final double duration = (end - start) / 1_000_000.0;
 					LOGGER.info("inserting the last " + count + " took " + duration + " ms; " + durationInManager

performanceDb/src/main/java/org/lucares/performance/db/TagsToFile.java

@@ -65,6 +65,7 @@ public class TagsToFile implements AutoCloseable, CollectionUtils {
 			}
 		} catch (final NullPointerException e) {
 			// TODO @ahr ludb should handle unknown fields better
+			e.printStackTrace();
 		}
 
 		Collections.sort(result, PdbFileByTimeAsc.INSTANCE);

recommind-logs/src/main/java/org/lucares/recommind/logs/TcpIngestor.java

@@ -25,7 +25,9 @@ import org.lucares.performance.db.PerformanceDb;
 import org.lucares.performance.db.Tags;
 
 import com.fasterxml.jackson.core.type.TypeReference;
+import com.fasterxml.jackson.databind.MappingIterator;
 import com.fasterxml.jackson.databind.ObjectMapper;
+import com.fasterxml.jackson.databind.ObjectReader;
 
 public class TcpIngestor implements AutoCloseable {
 
@@ -37,11 +39,14 @@ public class TcpIngestor implements AutoCloseable {
 
 	private final ExecutorService workerThreadPool = Executors.newCachedThreadPool();
 
-	private final ObjectMapper objectMapper = new ObjectMapper();
-
 	private final PerformanceDb db;
 
-	private final class Handler implements Callable<Void> {
+	public final static class Handler implements Callable<Void> {
+
+		private final ObjectMapper objectMapper = new ObjectMapper();
+
+		private final TypeReference<Map<String, Object>> typeReferenceForMap = new TypeReference<Map<String, Object>>() {
+		};
 
 		final Socket clientSocket;
 		private final ArrayBlockingQueue<Entry> queue;
@@ -56,24 +61,28 @@ public class TcpIngestor implements AutoCloseable {
 			Thread.currentThread().setName("worker-" + clientSocket.getInetAddress());
 			System.out.println("opening streams to client");
 			try (PrintWriter out = new PrintWriter(clientSocket.getOutputStream(), true);
-					BufferedReader in = new BufferedReader(new InputStreamReader(clientSocket.getInputStream()));) {
+					BufferedReader in = new BufferedReader(new InputStreamReader(clientSocket.getInputStream()));
+
+			) {
+				final ObjectReader objectReader = objectMapper.readerFor(typeReferenceForMap);
+				final MappingIterator<Object> iterator = objectReader.readValues(in);
 
 				double duration = 0.0;
 				int count = 0;
 				System.out.println("reading from stream");
-				String line;
-				while ((line = in.readLine()) != null) {
+				while (iterator.hasNext()) {
 
 					// System.out.println("read: " + line);
-					final long start = System.nanoTime();
+					final Map<String, Object> object = (Map<String, Object>) iterator.next();
 
-					final Optional<Entry> entry = createEntry(line);
+					final long start = System.nanoTime();
+					final Optional<Entry> entry = createEntry(object);
 					final long end = System.nanoTime();
 					duration += (end - start) / 1_000_000.0;
 
 					count++;
-					if (count == 10000) {
-						System.out.println("reading 10k took " + duration + "ms");
+					if (count == 100000) {
+						System.out.println("reading " + count + " took " + duration + "ms");
 						duration = 0.0;
 						count = 0;
 					}
@@ -89,12 +98,9 @@ public class TcpIngestor implements AutoCloseable {
 			return null;
 		}
 
-		private Optional<Entry> createEntry(final String line) {
+		public Optional<Entry> createEntry(final Map<String, Object> map) {
 			try {
 
-				final Map<String, Object> map = objectMapper.readValue(line, new TypeReference<Map<String, Object>>() {
-				});
-
 				final OffsetDateTime date = getDate(map);
 				final long duration = (int) map.get("duration");
 
@@ -147,7 +153,7 @@ public class TcpIngestor implements AutoCloseable {
 
 	public void start() throws Exception {
 
-		final ArrayBlockingQueue<Entry> queue = new ArrayBlockingQueue<>(1000);
+		final ArrayBlockingQueue<Entry> queue = new ArrayBlockingQueue<>(100000);
 
 		serverThreadPool.submit(() -> {
 			Thread.currentThread().setName("db-ingestion");