In the suite file example, there was a parameter set for the environment property file. In order to keep the parallel sessions from interfering with each other, different sets of servers and/or users must be used, and the thread that holds the properties during the test must also run in parallel. The following method extends the Java Properties class to accomplish that:

/**
 * ParallelProps method - extends Properties class to isolate 
   each thread instance
 * 
 */
public class ParallelProps extends Properties {
    public static final long serialVerionUID = 12345678L;
    private final ThreadLocal<Properties> localProperties = 
                                          new ThreadLocal<Properties>() {
        @Override
        protected Properties initialValue() {
            return new Properties();
        }
    };

    public ParallelProps(Properties properties) {
        super(properties);
    }

    @Override
    public String getProperty(String key) {
        String localValue = localProperties.get().getProperty(key);
        return localValue == null ? super.getProperty(key) : 
        localValue;
    }

    @Override
    public Object setProperty(String key, String value) {
        return localProperties.get().setProperty(key, value);
    }
}