Supported Java EE 6 and 7 feature combinations

Some combinations of Java™ EE 7 and Java EE 6 Liberty features in a server configuration are compatible. However, many combinations are not compatible and cause an error when the server starts.

The error message resembles:

CWWKF0033E: The singleton features com.ibm.websphere.appserver.javaeeCompatible-6.0 and 
com.ibm.websphere.appserver.javaeeCompatible-7.0 cannot be loaded at the same time.  The configured 
features servlet-3.0 and ejbLite-3.2 include one or more features that cause the conflict. Your 
configuration is not supported.

The following table marks compatible feature combinations with a checkmark (✔). Ensure that your server configuration does not contain incompatible features.

Table 1. Supported combinations of Java EE 7 and Java EE 6 Liberty features. Java EE 7 features are listed vertically. Java EE 6 features are listed horizontally. A checkmark (✔) indicates that the combination of Java EE 7 and 6 features is supported and a server configuration can contain both features. An empty cell (no ✔) indicates that the combination of Java EE 7 and 6 features is not supported.
  Java EE 6 features
beanValida- tion-1.0 cdi-1.0 ejbLite-3.1 jaxb-2.2 jaxrs-1.1 jaxws-2.2 jca-1.6 jms-1.1 jpa-2.0 jsf-2.0 jsp-2.2 managed- Beans-1.0 mdb-3.1 servlet-3.0
Java EE 7 features  
batch-1.0                    
beanValidation-1.1                    
cdi-1.2                    
concurrent-1.0
el-3.0  
ejb-3.2                    
ejbLite-3.2                    
javaMail-1.5
jacc-1.5
jaspic1.1
jaxrs-2.0                    
jca-1.7                    
jms-2.0                    
jpa-2.1                      
jsf-2.2                    
jsonp-1.0
jsp-2.3    
mdb-3.2                    
servlet-3.1  
websocket-1.0  
websocket-1.1  

The table shows that the servlet-3.0 feature of Java EE 6 is incompatible with the websocket-1.1 feature of Java EE 7. Thus, a server configuration with the following features causes an error:

<featureManager>
   <feature>servlet-3.0</feature>
   <feature>websocket-1.1</feature>
</featureManager>

To resolve the error, use servlet-3.1 instead of servlet-3.0 in the server configuration. The servlet-3.1 feature is compatible with the websocket-1.1 feature.

For more information on compatibility, or toleration, of features, see Tolerating features.