"Unknown option: -hostfile" when using distributed TestNG

i'd like to set up a distributed TestNG with 1 master PC and several slave PCs. But when i start the master with follwing command:

java org.testng.TestNG -hostfile hosts.properties testng1.xml

TestNG returns the error:

Unknown option: -hostfile

TestNG version is 6.1.1, 开发者_如何转开发haven't tried other version yet.

is this feature removed in this version?

any idea? thanks

checked TestNG codes, the option has been changed to "-master"