ChangeLogTag:Wed Mar 10 11:29:13 UTC 2004 Johnny Willemsen <jwillemsen@remedy.nl>

1 files changed, 19 insertions, 22 deletions

diff --git a/protocols/ace/TMCast/README b/protocols/ace/TMCast/README
index 43e35c52388..9e6299d8c2c 100644
--- a/protocols/ace/TMCast/README
+++ b/protocols/ace/TMCast/README
@@ -1,17 +1,15 @@
-
-
 Architecture
 
 TMCast (stands for Transaction MultiCast) is an implementation of a
 transactional multicast protocol. In essence, the idea is to represent
-each message delivery to members of a multicast group as a transaction - 
-an atomic, consistent and isolated action. A multicast transaction can
-be viewed as an atomic transition of the group members to a new state. 
-If we define [Mo] as a set of operational (non-faulty) members of the 
-group, [Mf] as a set of faulty members of the group, [Ma] as a set of 
-members that view transition [Tn] as aborted and [Mc] as a set of members 
-that view transition [Tn] as committed, then this atomic transition [Tn]
-should satisfy one of the following equations:
+each message delivery to members of a multicast group as a transaction
+- an atomic, consistent and isolated action. A multicast transaction
+can be viewed as an atomic transition of the group members to a new
+state.  If we define [Mo] as a set of operational (non-faulty) members
+of the group, [Mf] as a set of faulty members of the group, [Ma] as a
+set of members that view transition [Tn] as aborted and [Mc] as a set
+of members that view transition [Tn] as committed, then this atomic
+transition [Tn] should satisfy one of the following equations:
 
 Mo(Tn-1) = Ma(T) U Mf(T)
 Mo(Tn-1) = Mc(T) U Mf(T)
@@ -20,21 +18,20 @@ Or, in other words, after transaction T has been committed (aborted),
 all operational (before transaction T) members are either in the
 committed (aborted) or failed state.
 
-Thus, for each member of the group, outcome of the transaction can
-be commit, abort or a member failure. It is important for a member
-to exhibit a failfast (error latency is less than transaction cycle) 
-behavior. Or, in other words, if a member transitioned into a wrong 
+Thus, for each member of the group, outcome of the transaction can be
+commit, abort or a member failure. It is important for a member to
+exhibit a failfast (error latency is less than transaction cycle)
+behavior. Or, in other words, if a member transitioned into a wrong
 state, it is guaranteed to fail instead of delivering a wrong result.
 
-In order to achieve such an error detection in a decentralized 
-environment, certain limitations were imposed. One of the most 
-user-visible limitation is the fact that the lifetime of the group 
-with only one member is very short. This is because there is not way 
+In order to achieve such an error detection in a decentralized
+environment, certain limitations were imposed. One of the most
+user-visible limitation is the fact that the lifetime of the group
+with only one member is very short. This is because there is not way
 for a member to distinguish "no members yet" case from "my link to the
-group is down". In such a situation, the member assumes the latter case. 
-There is also a military saying that puts it quite nicely: two is one, 
-one is nothing.
-
+group is down". In such a situation, the member assumes the latter
+case.  There is also a military saying that puts it quite nicely: two
+is one, one is nothing.
 
 State of Implementation