fix missing/wrong logging

1. Log the exception in PdbFileIterator with a logger instead
   of just printing it to stderr.
2. Increase log level for exceptions when inserting entries.
3. Log exception when creation of entry failed in TcpIngestor.

pdb-ui/src/main/java/org/lucares/pdbui/TcpIngestor.java

@@ -124,6 +124,7 @@ public class TcpIngestor implements Ingestor, AutoCloseable, DisposableBean {
 				final Entry entry = new Entry(date, duration, tags);
 				return Optional.of(entry);
 			} catch (final Exception e) {
+				LOGGER.error("Failed to create entry.", e);
 				return Optional.empty();
 			}
 		}

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

@@ -8,9 +8,13 @@ import java.util.Queue;
 import java.util.function.Supplier;
 
 import org.lucares.pdb.api.Entry;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 
 public class PdbFileIterator implements Iterator<Entry>, AutoCloseable {
 
+	private final static Logger LOGGER = LoggerFactory.getLogger(PdbFileIterator.class);
+
 	private static final class EntrySupplier implements Supplier<Entry>, AutoCloseable {
 
 		private final Queue<PdbReader> pdbFiles;
@@ -65,7 +69,7 @@ public class PdbFileIterator implements Iterator<Entry>, AutoCloseable {
 				try {
 					pdbFiles.poll().close();
 				} catch (final Exception e) {
-					e.printStackTrace();
+					LOGGER.warn("Closing pdb file failed.", e);
 				}
 			}
 		}

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

@@ -103,7 +103,7 @@ public class PerformanceDb implements AutoCloseable {
 				} catch (final InvalidValueException | SyntaxException e) {
 
 					LOGGER.info("skipping entry: " + e.getMessage() + " : " + entry);
-					LOGGER.debug("", e);
+					LOGGER.info("", e);
 				}
 			}