--- a/stress-tester/src/main/java/com/passus/st/emitter/raw/DpdkUnidirectionalRawPacketEmitter.java	Thu Jul 09 14:15:53 2020 +0200
+++ b/stress-tester/src/main/java/com/passus/st/emitter/raw/DpdkUnidirectionalRawPacketEmitter.java	Thu Jul 09 15:11:35 2020 +0200
@@ -53,7 +53,7 @@
             MapNodeDefinition def = super.create();
             def.add(
                     tupleDef("bufferSize", INT_GREATER_EQUAL_ZERO_DEF).setRequired(false),
-                    tupleDef("bufferFlushPeriod", LONG_GREATER_THAN_ZERO_DEF).setRequired(false),
+                    tupleDef("bufferFlushPeriod", LONG_GREATER_EQUAL_ZERO_DEF).setRequired(false),
                     tupleDef("verbosity", INT_GREATER_EQUAL_ZERO_DEF).setRequired(false)
             );
             return def;

--- a/stress-tester/src/main/java/com/passus/st/emitter/raw/DpdkUnidirectionalRawPacketWorker.java	Thu Jul 09 14:15:53 2020 +0200
+++ b/stress-tester/src/main/java/com/passus/st/emitter/raw/DpdkUnidirectionalRawPacketWorker.java	Thu Jul 09 15:11:35 2020 +0200
@@ -19,7 +19,7 @@
 
     public static final int MAX_BUFFER_SIZE = DpdkAO.sendBuffSize();
     public static final int DEFAULT_BUFFER_SIZE = 0;
-    public static final long DEFAULT_FLUSH_PERIOD = 50;
+    public static final long DEFAULT_FLUSH_PERIOD = 0;
     public static final int DEFAULT_VERBOSITY = 1;
 
     private DpdkAO dpdkAO;
@@ -132,24 +132,39 @@
                 bufferLengths = new int[bufferSize];
                 bufferPkts = 0;
 
-//                scheduler = new DefaultScheduledTimerService(getClass().getSimpleName() + "-Scheduler", bufferFlushPeriod, this::flushBuffer);
-//                scheduler.start();
+                if (bufferFlushPeriod > 0) {
+                    scheduler = new DefaultScheduledTimerService(getClass().getSimpleName() + "-Scheduler", bufferFlushPeriod, this::flushBuffer);
+                    scheduler.start();
+                }
             }
         }
     }
 
     @Override
     protected void onFinish() {
-        if (scheduler != null) {
-            scheduler.stop();
-            scheduler = null;
+        synchronized (this) {
+            if (scheduler != null) {
+                scheduler.stop();
+                scheduler = null;
+            }
+        }
+
+        synchronized (DpdkAO.class) {
+            if (dpdkInitCalls > 0) {
+                dpdkInitCalls--;
+                if (dpdkInitCalls == 0) {
+                    DpdkAO.cleanApp();
+                }
+            }
         }
     }
 
     private void flushBuffer() {
-        synchronized (this) {
-            DpdkAO.sendPackets0(bufferBytes, bufferLengths, bufferPkts);
-            bufferPkts = 0;
+        if (bufferPkts > 0) {
+            synchronized (this) {
+                DpdkAO.sendPackets0(bufferBytes, bufferLengths, bufferPkts);
+                bufferPkts = 0;
+            }
         }
     }
 
@@ -180,13 +195,5 @@
         if (bufferSize > 0) {
             flushBuffer();
         }
-        synchronized (DpdkAO.class) {
-            if (dpdkInitCalls > 0) {
-                dpdkInitCalls--;
-                if (dpdkInitCalls == 0) {
-                    DpdkAO.cleanApp();
-                }
-            }
-        }
     }
 }