Java Reference
In-Depth Information
While this session creation request is going on,
NodeA
will also send back an asynchron-
ous message that contains the cluster topology. The JBoss
EJB Client
implementation
will take note of this topology information and will later use it to create connections to the
nodes within the cluster and route invocations to those nodes, whenever necessary.
Now let's assume that
NodeA
goes down and the client application subsequently invokes
on the proxy. At this stage, the
JBoss EJB Client
implementation will be aware of the
cluster topology; therefore, it knows that the cluster has two nodes:
NodeA
and
NodeB
.
Now when the invocation arrives, it detects that
NodeA
is down, so it uses a selector to
fetch a suitable node from among the cluster nodes. This exchange is shown in the follow-
ing diagram:
If a suitable node is found, the
JBoss EJB Client
implementation creates a connection to
that node (in our case
NodeB
) and creates an EJB receiver out of it. At the end of this pro-
cess, the invocation has now been effectively failed over to a different node within the
cluster.
