diff --git a/src/main/java/ch/ethz/seb/sebserver/webservice/servicelayer/session/impl/SEBClientEventBatchService.java b/src/main/java/ch/ethz/seb/sebserver/webservice/servicelayer/session/impl/SEBClientEventBatchService.java
index 7a262eca..a7674577 100644
--- a/src/main/java/ch/ethz/seb/sebserver/webservice/servicelayer/session/impl/SEBClientEventBatchService.java
+++ b/src/main/java/ch/ethz/seb/sebserver/webservice/servicelayer/session/impl/SEBClientEventBatchService.java
@@ -161,10 +161,10 @@ public class SEBClientEventBatchService {
             }
 
             ClientConnectionDataInternal clientConnection = null;
-            synchronized (ExamSessionCacheService.CLIENT_CONNECTION_CREATION_LOCK) {
-                clientConnection = this.examSessionCacheService
-                        .getClientConnection(eventData.connectionToken);
-            }
+            //synchronized (ExamSessionCacheService.CLIENT_CONNECTION_CREATION_LOCK) {
+            clientConnection = this.examSessionCacheService
+                    .getClientConnection(eventData.connectionToken);
+            //}
 
             if (clientConnection == null) {
                 log.error("Failed to get ClientConnectionDataInternal for: {}", eventData.connectionToken);
@@ -208,10 +208,10 @@ public class SEBClientEventBatchService {
         try {
 
             ClientConnectionDataInternal clientConnection = null;
-            synchronized (ExamSessionCacheService.CLIENT_CONNECTION_CREATION_LOCK) {
-                clientConnection = this.examSessionCacheService
-                        .getClientConnection(eventData.connectionToken);
-            }
+            //synchronized (ExamSessionCacheService.CLIENT_CONNECTION_CREATION_LOCK) {
+            clientConnection = this.examSessionCacheService
+                    .getClientConnection(eventData.connectionToken);
+            //}
 
             if (clientConnection == null) {
                 log.warn("Failed to retrieve ClientConnection for token {}. Skip this event",
diff --git a/src/main/java/ch/ethz/seb/sebserver/webservice/servicelayer/session/impl/SEBClientPingBatchService.java b/src/main/java/ch/ethz/seb/sebserver/webservice/servicelayer/session/impl/SEBClientPingBatchService.java
index 44a86a95..f0e69a81 100644
--- a/src/main/java/ch/ethz/seb/sebserver/webservice/servicelayer/session/impl/SEBClientPingBatchService.java
+++ b/src/main/java/ch/ethz/seb/sebserver/webservice/servicelayer/session/impl/SEBClientPingBatchService.java
@@ -92,10 +92,10 @@ public class SEBClientPingBatchService {
         }
 
         ClientConnectionDataInternal activeClientConnection = null;
-        synchronized (ExamSessionCacheService.CLIENT_CONNECTION_CREATION_LOCK) {
-            activeClientConnection = this.examSessionCacheService
-                    .getClientConnection(connectionToken);
-        }
+        //synchronized (ExamSessionCacheService.CLIENT_CONNECTION_CREATION_LOCK) {
+        activeClientConnection = this.examSessionCacheService
+                .getClientConnection(connectionToken);
+        //}
 
         if (activeClientConnection != null) {
             activeClientConnection.notifyPing(timestamp);