chore: add additional logging for efm

Author: crystall-bitquill

wrapper/src/main/java/software/amazon/jdbc/plugin/efm/MonitorImpl.java

@@ -94,6 +94,9 @@ public MonitorImpl(
 
   @Override
   public void startMonitoring(final MonitorConnectionContext context) {
+    if (this.stopped) {
+      LOGGER.warning(() -> Messages.get("MonitorImpl.monitorIsStopped"));
+    }
     final long currentTimeNano = this.getCurrentTimeNano();
     context.setStartMonitorTimeNano(currentTimeNano);
     this.contextLastUsedTimestampNano = currentTimeNano;
@@ -222,12 +225,24 @@ public void run() {
       }
     } catch (final InterruptedException intEx) {
       // do nothing; exit thread
+      LOGGER.warning(
+          () -> Messages.get(
+              "MonitorImpl.interruptedExceptionDuringMonitoring",
+              new Object[] {this.hostSpec.getHost(), intEx.getMessage()}));
+    } catch (final Exception ex) {
+      // do nothing; exit thread
+      LOGGER.warning(
+          () -> Messages.get(
+              "MonitorImpl.exceptionDuringMonitoring",
+              new Object[] {this.hostSpec.getHost(), ex.getMessage()}));
     } finally {
       if (this.monitoringConn != null) {
         try {
           this.monitoringConn.close();
         } catch (final SQLException ex) {
           // ignore
+          LOGGER.warning(
+              () -> Messages.get("MonitorImpl.exceptionClosingMonitoringConn", new Object[] {ex.getMessage()}));
         }
       }
       this.stopped = true;

wrapper/src/main/resources/aws_advanced_jdbc_wrapper_messages.properties

@@ -188,6 +188,10 @@ MonitorThreadContainer.emptyNodeKeys=Provided node keys are empty.
 
 # Monitor Impl
 MonitorImpl.contextNullWarning=Parameter 'context' should not be null.
+MonitorImpl.exceptionClosingMonitoringConn=An exception was thrown when trying to close the monitoring connection: {0}
+MonitorImpl.interruptedExceptionDuringMonitoring=Monitoring thread for node {0} was interrupted: {1}
+MonitorImpl.exceptionDuringMonitoring=Unhandled exception in monitoring thread for node {0}: {1}
+MonitorImpl.monitorIsStopped=Monitor has already stopped.
 
 # Monitor Service Impl
 MonitorServiceImpl.nullMonitorParam=Parameter 'monitor' should not be null.