I am working on new features in the AMQP Protocol Handler, and I would
like to explain here what I am doing:
I needed to go beyond what we do now with AMQP, and use it connect
brokers, and eventually with qpid-dispatch for more elaborate
networking on datacenters.
First part:
The first issue I had while implementing something protocol specific
(other than Core) was to use the classes within the protocol package.
As the broker is agnostic to the protocols (exception is core ATM), I
needed the whole initialization to take place within
artemis-amqp-protocol.
To get around that I added what I called ProtocolServices. So when you
implement a protocol service the interface will be called within
broker start.
Second part:
As the broker is now taking action on connecting to other brokers (or
other AMQP servers), I needed to change out Netty bootstrapping to
allow outgoing connections with a given protocol. With that I'm
inverting everything we had for server, and I am abusing the power of
AMQP here. Since AMQP is totally symmetrical I can now connect brokers
directly. So, a Consumer on the broker and be connected directly to a
producer on another broker. Acting like a bridge, but way more
lightweight.
Third part:
I am using that for replicas. At the moment these replicas will not
sync the client, but they are working quite nicely. and allowing
multiple replicas.
The configuration will take part as the following.
You define amqp connections with their URL and their reconnecting
information, for each connection you can define:
sender <matching addresses>: All addresses matching will have a
transfer sender. This will act like a push bridge
receiver < matching addresses>: All matching addresses on this broker
will create a consumer pulling messages. This will act like a pull
bridge
peer <matching addresses>: This will create both ways, but you can
only use this towards a special server that knows how to handle this.
(e.g. qpid-dispatch). otherwise you get ping pongs on transfers
copy <matching addresses> : This will create a replica, without
sending the acks, (You will be responsible to consume the messages
yourself at the target broker)
replica <matching addresses>: Just like copy, but acks are sent and
messages removed upong ack (or accept)
This is an example of the configuration:
<amqp-connections>
<!-- the connection towards another broker -->
<amqp-connection uri="tcp://otherNode:5671" name="myconnection"
retry-interval="333" reconnect-attempts="33">
<sender match="TEST-SENDER" />
<receiver match="TEST-RECEIVER" />
<peer match="TEST-PEER"/>
<copy match="TEST-COPY"/>
<replica match="TEST-REPLICA"/>
</amqp-connection>
</amqp-connections>
so far these are being worked on a my github fork/ but it's not really
meant for a review at this point as I have some cleanup to do (some
logging messages and stuff I have to remove).
I am getting ready to send a Pull Request early next week. but you
have the concepts here already to review them.
--
Clebert Suconic
