[Spread-users] problem re-using private names with 3.17.0

Yair Amir yairamir at cnds.jhu.edu
Mon Oct 28 15:05:53 EST 2002

Hi Sean,

I am not sure I understand your message.

Assuming you mean "joining the group" when you write "logging into the
group" then we currently are not using the same service for
connecting to Spread and for joining/leaving a group.

It is sufficient to use an AGREED message for the join and leave
events. Until a version or two ago we used the SAFE service for this
but this was not necessary. AGREED is much faster (about 4 times...)
and is absolutely correct to use in this implementation of Spread.

In terms of the connect/disconnect, we currently are using the
SAFE service, which is absolutely correct to do and should provide
more information in terms of when you disconnected in terms of the
stream of messages. Note that the safe and agreed services provide
exactly the same ordering guarantee so there is no issue in using
connect/disconnect as safe while join/leave as agreed.


        :) Yair.

>> If you disconnect and immediately connect with the same name, it is
>> very likely to get the not-unique rejection and this is perfectly
>> normal and is the intended outcome (and not a bug).
>> Upon disconnection, Spread passes a safe message to let everyone
>> knows that this guy disconnected and only upon delivery of this
>> message it actually clears this guy out. In the meantime, connecting
>> with the same name will be rejected. Usually this should take a
>> small amount of time, very likely less than a second in local area
>> networks.

Sean> Does it not use a safe message for logging into the group?  I'd think
Sean> with ordered delivery that this wouldn't be an issue.  What's the
Sean> message type used on a login attempt?  If the message type is anything
Sean> but the same as the disconnection message... well...  that behavior
Sean> doesn't make sense to me.  In what cases/situations would this be
Sean> desired?  -sc

More information about the Spread-users mailing list