diff --git a/src/main/java/org/gcube/data/spd/resources/Executor.java b/src/main/java/org/gcube/data/spd/resources/Executor.java
index baa0b92..4339f81 100644
--- a/src/main/java/org/gcube/data/spd/resources/Executor.java
+++ b/src/main/java/org/gcube/data/spd/resources/Executor.java
@@ -48,7 +48,7 @@ public class Executor {
 
 	private static Logger logger = LoggerFactory.getLogger(Executor.class);
 
-
+	private static final String ID_SEPARATOR = "_"; 
 
 	AppInitializer initializer = (AppInitializer)ApplicationManagerProvider.get(AppInitializer.class);
 
@@ -216,7 +216,7 @@ public class Executor {
 
 	private static String extractNode(String key) throws IdNotValidException{
 		logger.trace("id arrived is {}", key );
-		String[] splitted = key.split("_");
+		String[] splitted = key.split(ID_SEPARATOR);
 		if (splitted.length==2)
 			return splitted[0];
 		else throw new IdNotValidException();
@@ -224,7 +224,7 @@ public class Executor {
 
 	private static String extractId(String key) throws IdNotValidException{
 		logger.trace("id arrived is {}", key );
-		String[] splitted = key.split("_");
+		String[] splitted = key.split(ID_SEPARATOR);
 		if (splitted.length==2)
 			return splitted[1];
 		else throw new IdNotValidException();
@@ -233,7 +233,7 @@ public class Executor {
 	private String createKey(String id){
 		logger.trace("id arrived is {}", id );
 		String node = cxt.container().profile(HostingNode.class).id();
-		return node+"_"+id;
+		return node+ID_SEPARATOR+id;
 	}
 	/*
 	private Executor remoteJobCall(String riId) throws InvalidIdentifierException{